Subject: RE: RE: Teres-Bearing & Platter - Open Items Date: Mon, 7 Feb 2000 10:25:23 -0700 From: Mackris, Thom G., Mackris, Thom G. To: Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Schei (h), Ken; Schei (w), Ken; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve Absolutely George! Thanks for pointing it out. Pricing the project definitely needs to take the possibility of subcontracting the acrylic bonding task. Thom -----Original Message----- From: George Munger [mailto:GMunger@mnr.org] Subject: Re: RE: Teres-Bearing & Platter - Open Items Maybe, if others agree and not already done (please forgive me if I missed it), add an action item to nail down labor and material costs for item #4 acrylic layers & bonding. GM ----- Original Message ----- From: Thom Mackris / Joan Panzella Sent: Saturday, February 05, 2000 8:47 AM Subject: Re: Teres-Bearing & Platter - Open Items All, As we were getting in the final days of solidifying the bearing and platter design (the first time around), Chris put together a list of issues, both open and closed. I think it's a good idea to do the same at this point. I don't really see any of the following items as true issues, more as requests for clarification as well as for "refinements" in the design. Correct me if I'm wrong on this one. There are indeed some action items arising from these "issues", which I've noted as best as I can. I have not plowed through the last week's e-mails, and so I may be missing something here. Additionally, I'm rushed to get out of the house at the moment, but I think this should get out as soon as possible - not waiting until tonight. Please don't be shy with your comments. Having said that, I continue to be amazed at the how the major elements of this design have held up the the scrutiny of this highly competent group. Let the group know if I've missed something or you have more to add. 1) Use of Delrin as a thrust plate: ## closed ## . We are using Bryce's vast experience in this area in conjunction with the experiences of Ken and Igor with this material. Delrin is an excellent compromise between quiet (teflon) and strong (brass/bronze) and may be the compromise that Hartmut was looking for when he replaced his teflon plate in his Scheu with a hard substance. It is more than robust enough for a 15 lb. platter, and it is field replacable (see below). 2) Field replacable thrust plate: ## closed ##. Bryce indicates that there is no problem with a drop-in thrust plate replacement with respect to bearing perfomrance (noise & chatter). Replacement will require no tools other than perhaps a pencil with a piece of "blu-tak" on the end of it to retrieve the plate from the bearing well. I suspect that this would be done by cooling down the bearing and allowing the differing thermal expansion coefficients to "loosen up" the fit. Action item: Make clear the specifics of replacing the thrust plate. 3) Decreasing the size of the bearing well ## closed ##. This must be done due to material costs. Bryce indicated that we have specified too large of a piece of brass as far as cost threshold is concerned. The price would jump significantly if we maintained the current size. We are only marginally above this dimensional threshold, and the space needs to be recoverd by sacrificing part of the bearing well. Igor would like to have as much oil damping as possible and suggested that some of the well volume be recovered by "necking down" the bearing shaft. Bryce indicated that this would compromise the excellent tolerances he expects to attain on the shaft. These tolerances are attributable to the thickiness (and hence rigidity) of the shaft. To date, we've had no one question that the #1 priority is to machine the absolute best tolerances possible. 4) Use of three layers of acrylic for platter ## closed ## Action items: (4a) We need to confirm that the glue will ensure a good weld, that is cosmetically and structurally acceptable with respect to the platter having a machined finish. (4b) We may learn that Bryce will need to subcontract out the task of making 3" thick blanks to work from. I have to sign off ... there may be more, but this will certainly get us started. Thanks for your feedback, Thom Subject: [teres] RE: Scheu Bearing Date: Mon, 7 Feb 2000 06:07:53 -0700 From: Tony Bombera, Tony Bombera To: teres@aiko.com Hi All, A day before I joined this group I have received the Scheu bearing and motor. The bearing is different from the one on my plans (and likely yours). (I think in metric, 1 inch=25.4mm.) It is an inverted bearing, the shaft is 16mm in diameter with a ball on top. The outer (female)part is 20mm in diameter, all one piece with record spindle. The record spindle has a threaded hole in it which is likely going all the way through(?) The thrust plate has a small hole on through it as well. The shaft is 39mm long out of which 35mm is in the famale part. There is M8 hole from the bottom of the shaft and the bearing attaches with a M8 hex socket cap screw. The shaft sits in an oil tub. From what I understood in German, capillary effect sends the oil up from the tub. I have priced Maxon motor in 1997 (Sound Practices type). 5-19 piece price was US $67.40. Regards, Tony Bombera tbombera@pathcom.com Subject: RE: Teres-Bearing & Platter Date: Mon, 7 Feb 2000 08:48:15 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'Chris Brady'; jhlane CC: Mackris, Thom G.; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Primrose, Roscoe; Schei (h), Ken; Schei, Kenneth; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve I agree with Bryce that a spiral groove isn't reauired. In fact if we had one, we would have to provide a return channel to prevent pumping most of the oil out of the bearing and onto our beautiful cherry veneer (or whatever) plinth. I also don't think that any other mechanism is needed to be added to the present design. If we have the reservoir filled with the proper oil, because of capillary action and the spinning action it will be impossible not to have oil in the upper bearing. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Chris Brady [SMTP:cbrady@sgi.com] > Sent: Friday, February 04, 2000 12:32 AM > To: jhlane > Cc: Mackris, Thom G.; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, > Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, > Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein > (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, > Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Mackris (h), Thom; > Martin (w), Thomas; Martin(h), Thomas; Mitaru, Alex; Mollard, William; > Munger (w), George; Ono, Stewart; Pao, Sammy; Primrose, Roscoe; Schei (h), > Ken; Schei (w), Ken; Sellek, Grant; Suess, David; Welborne, Ron; Wright, > Allen; Zettell, Steve > Subject: Re: Teres-Bearing & Platter > > I just had a long conversation with Bryce (our machinist) about > details of the turntable design. As usual he had some very good > insights and suggested some minor adjustments to the bearing design. > He also had some minor concerns that he wanted me to pass on to > the group. > > I confirmed with Bryce that the Delrin thrust plate will just > drop into the bottom of the bearing housing and will be trivial to > remove. There is no need for a press fit since the contact area > with the bottom of the bearing housing will be much larger than > the contact with the shaft (i.e.. it will not move at all). So if > anyone wants to try a different material it will be very easy. > Bryce also feels confident that Delrin is the best material for > the thrust plate, but we will be free to try anything we want. > > I talked to Bryce about the idea of the spiraled groove in the > bearing surface to "pump" oil to the top. He liked this idea but > thought it unnecessary since we have an oil bath. However, the > discussion got him thinking about how we could better insure > complete lubrication of the top portion of the bearing. He > suggested cutting a shallow well into the top of the bearing to > hold a small pool of oil at the top of the bearing. This would > insure liberal lubrication of the top bearing surfaces. This seems > like very very good idea. I will try to update the bearing drawing > soon to better illustrate this concept. He also indicated that the > diameter of the recessed area in the bearing needs to be reduced from > 1.0" to about .81" due to machining constraints. This seems to be > of little consequence especially since there will be an additional > oil reservoir at the top. > > For those new to the group the platters will be made from three > layers of 1" acrylic laminated together. The reason for this is > the huge cost of acrylic more than 1" thick. With proper glue and > clamping a joint in acrylic is invisible even when the acrylic is > polished. However, Bryce is uncertain about being able to force > all of the bubbles out of such a large surface area to make > an invisible joint. This is purely a cosmetic issue and with the > machined finish it is unlikely that small bubbles (if there are > any) would be visible. > > Also the raw material for the platter will be 3" thick but after > machining both sides the final thickness will be roughly 2 15/16 not > 3". An item of little consequence but we don't want anyone to be > surprised. > > A couple of list members have expressed interest in having Bryce do > some extra "one-off" machining for them. Bryce has too much on his > plate to do this kind of work and also thought that for one of a kind > machining we would be better served to use a local machinist. > > Bryce has been a valuable resource in the design process and has spent > a many hours providing us with free, expert advise. I for one am > grateful. > > Chris Subject: RE: Teres Bearing & Platter Date: Mon, 7 Feb 2000 08:53:05 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'Igor Kuznetsoff'; Thom Mackris / Joan Panzella; Tony Bombera; Tim Bailey; Thomas Martin(w); Thomas Martin (h); Thom Mackris (w); Terry Gesualdo; Stewart Ono; Steve Zettel; Stan Goudge; Sammy Pao; Roscoe Primrose; Ron Welborne; Peter Clark; Peter Boser; Mitaru, Alex; Schei, Kenneth; Ken Schei (h); Jon Lane; Joe Druley; Jeremy Epstein (w); Ivan Anderson; Grant Sellek; Grant Gassman (h); George Munger (w); Gary Bronner; Fred Humphrey; Don Carron; David Suess; Dave Collier (w); Chris Brady; Brian Day (h); Brian Boehler; Bill Mollard; Beck, Chris; Allen Wright; Gon, Martin I agree with Igor. I think "smooth" brass is better for our application. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Igor Kuznetsoff [SMTP:gorkuz@yahoo.com] > Sent: Friday, February 04, 2000 2:44 AM > To: Thom Mackris / Joan Panzella; Tony Bombera; Tim Bailey; Thomas > Martin(w); Thomas Martin (h); Thom Mackris (w); Terry Gesualdo; Stewart > Ono; Steve Zettel; Stan Goudge; Sammy Pao; Roscoe Primrose; Ron Welborne; > Peter Clark; Peter Boser; Mitaru, Alex; Ken Schei (w); Ken Schei (h); Jon > Lane; Joe Druley; Jeremy Epstein (w); Ivan Anderson; Grant Sellek; Grant > Gassman (h); George Munger (w); Gary Bronner; Fred Humphrey; Don Carron; > David Suess; Dave Collier (w); Chris Brady; Brian Day (h); Brian Boehler; > Bill Mollard; Beck, Chris; Allen Wright; Gon, Martin > Subject: Re: Teres Bearing & Platter > > > > I may be wrong about the brass vs. bronze sidewall > > issue, but if I recall, > > scintered bronze has advantages when lubrication is > > problematic. Maybe > > Chris or Igor or Ken can help my memory here. > > Ah, well this isn't exactly my subject, but it seems > that I do remember that Sintered Bronze is the > material that is known as "Oilite", and is used > commonly as a bearing surface because the sintering > process, one of heat + pressure applied to powdered > material, produces a somewhat porous result, which has > the capability of holding lubricant in a sponge-like > manner. This is desirable in harsh duty/low > maintenance app's. Whether this is desirable for us > vs. the smoothness of brass (or non-sintered bronze), > which I would think will produce a *stronger*, more > coherent, film of oil with a better capability of > keeping the surfaces separated, and the operation > quieter, is a question probably answered better by > Bryce. Or, perhaps, if we have an appropriate > engineer / expert on this subject. > > Igor > > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com Subject: RE: Teres-Bearing & Platter Date: Mon, 7 Feb 2000 08:58:15 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'Mackris, Thom G.'; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Primrose, Roscoe; Schei (h), Ken; Schei, Kenneth; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve There shouldn't be any appreciable residual stress from bonding flat pieces of identical material together. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Mackris, Thom G. [SMTP:tgmackris@vicorpinc.com] > Sent: Friday, February 04, 2000 10:44 AM > To: Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, > Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, > Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), > Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; > Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), > Thom; Martin (w), Thomas; Martin(h), Thomas; Mitaru, Alex; Mollard, > William; Munger (w), George; Ono, Stewart; Pao, Sammy; Primrose, Roscoe; > Schei (h), Ken; Schei (w), Ken; Sellek, Grant; Suess, David; Welborne, > Ron; Wright, Allen; Zettell, Steve > Subject: RE: Teres-Bearing & Platter > > If we're truly welding the layers together, is there really any stress? > Anyone? > > Thom > > -----Original Message----- > From: StepHydro@aol.com [mailto:StepHydro@aol.com] > Sent: Friday, February 04, 2000 10:28 AM > Subject: Re: Teres-Bearing & Platter > > > In a message dated 00-02-04 10:15:01 EST, briday@uswest.net writes: > > << A vacuum bag press would work best here. It would ensure no bubbles, > but > more importantly even distribution of the adhesive. With conventional > clamping, adhesive thickness variation and bubbles will make for possible > balance issues. >> > > > I think this stuff bonds too quickly for a vacuum press to help. I also > wonder about the possibility of building stress into the platter that will > > cause problems later...regardless of how it is bonded. > > Cheers/Carron Subject: RE: Teres-Bearing & Platter:misc thoughts Date: Mon, 7 Feb 2000 09:34:12 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'Mackris, Thom G.'; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Primrose, Roscoe; Schei, Kenneth; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve The coefficient of expansion of brass is about 9.8 X 10^-6, or 0.0000098 in/in/degree F. Stainless steel is 0.0000065. The difference is 0.0000033. For a change of 10 degrees F, the differential expansion would be 10 X 0.0000033 = 0.000033 in/in. The radius of the bearing is 0.375". Therefore the differential in dimensions at the bearing face will be 0.000033 X 0.375 = 0.0000124". Our 0.0002" tolerance will easily accommodate that differential. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Mackris, Thom G. [SMTP:tgmackris@vicorpinc.com] > Sent: Friday, February 04, 2000 2:29 PM > To: Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, > Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, > Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), > Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; > Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), > Thom; Martin (w), Thomas; Martin(h), Thomas; Mitaru, Alex; Mollard, > William; Munger (w), George; Ono, Stewart; Pao, Sammy; Primrose, Roscoe; > Schei (h), Ken; Schei (w), Ken; Sellek, Grant; Suess, David; Welborne, > Ron; Wright, Allen; Zettell, Steve > Subject: RE: Teres-Bearing & Platter:misc thoughts > > Hi Stu, > > If memory serves, the end of the LP 12 male bearing (spindle) is shaped > like > a tip toe (conical) rather than speherical, FWIW. > > You report yet one more reason to have an oil resevoir - cooling / > dimensional stability. Ken Schei (Structural Engineer) is our man with > respect to thermal expansion coefficents (brass female bearing vs. > stainless > steel male). I would have to guess that Bryce is cognizant of these > issues > and that in the case of Linn, the males were at opposite extremes of their > allowable tolerances, or perhaps machined at different room temperatures. > I > can see where at .0002 tolerances, this could make a difference. > Fortunately, ours will be machined in the same shop in a moderate climate > at > the same time of year. Take these rantings as not those of a bearing > expert, but just my humble prognostication. > > I had a brief conversation with Chris about the thrust plate and other > bearing related issues. I'll let him report back in full when he gets a > chance. If I understand him correctly, Bryce is comfortable with an > easily > removable delrin thrust plate from the perspective of: (a) It not > chattering or otherwise compromising the performance of the bearing. (b) > that delrin is plenty tough for this application. If (a) is true, we have > field replacable components so (b) is not an issue and everyone can > experiment to their heart's content. > > With respect to flame polished vs. a machined surface, you correctly > mention > the possibility of dimensional changes. Another concern we have about > going > to clear is one of providing a good frictional surface for the belt. With > a > rubber belt, this is probably not an issue, but it certainly would be > instructive to be able to experiment with string, floss, and magnetic > recording tape (Sound Practices #10 - "Turn Your Table" article). It > seems > as if while most of the early group liked the look of clear (flame > polished) > acrylic, the concern about friction as well as the eventual small > scratches > that will innevitablly get on the platter resulted in most of us nixing > the > idea of polished. Bryce had mentioned a concern about the cosmetics of > the > machined surface - if someone touches it with greasy fingers it might be > difficult to clean. I know, we all keep our records in a clean room and > wash our hands with distilled water before approaching the alter known as > our turntable stand . > > As far as a 3" vs. 2" platter is conerned. We originally had spec'd out > the > platter at 2" for the reasons you state - making it out of one piece out > of > the thickest "reasonably" priced material. As we thought more about the > stability (teeter-toter) issues, we decided to drop the center of gravity > of > the platter lower by use of a 3" bearing. I'm guessing that from an > overall > stability viewpoint that this is still a superior choice. > > I think you are correct in stating that we should really get clear about > how > the platters will be bonded. The question of a frosted vs. machined > finish > came up and no one knew how the frosting was accomplished or whether it > would affect the precision of the machining. This is a piece of > information > we should obtain. ** Chris ** take ** note ** Perhaps this is a > question > for Bryce? > > A very real question arises here: If we agree that 3" is superior to 2" > from a dynamic balance perspective, are we willing to take the risk of > slight cosmetic imperfections, which for the most part will be masked by > the > machined (or frosted) surface? It seems to me that for reasons of form > following function, that the answer is yes to a 3", machined (or frosted) > surface. > > Thanks for the thoughts, Stu ... keep 'em comming. When we're all happy, > we'll either have a bullet proof design, or one that is hopelessly > compromised. I strongly suspect that it will be the former (bullet > proof), > however. > > Cheers, > Thom > > > -----Original Message----- > From: Stewart Ono [mailto:audiodir@gte.net] > Sent: Friday, February 04, 2000 11:10 AM > Subject: Re: Teres-Bearing & Platter:misc thoughts > > > In regards to Jon Lane's comments, I once received a Linn LP-12 brand new > where the bearing was machined 2/10,000th's oversized. It spun well when > cold but would actually freeze up solid (you couldn't pull the inner > platter > out without employing considerable force after playing just one side of an > album). This was with the recommended amount of oil inserted in the well > and > I believe the Linn uses Delrin inserts for the bearing well. I do not > claim > to be very cognizant of the temperature coefficients involved here, but > tight tolerances mean some consistent temperatures must be maintained. It > seems to me that a slight pumping action coupled with an oversized well > and > oversized bearings insures more of a temperature constant and also means > less long term maintenance. Of course, a large oil sump may probably be > equally effective. As for the problem of the bearing spindle radius to > thrust pad contact patch, my experience with other fields indicates that > the > bearing will quickly wear a pattern in the pad material large enough to > suspend the weight and, barring actual disintegration of the materials, > stop > wearing for a significantly long period of time. > > As far as a one shot project is concerned, as this one is, we ought to > plan > for every contingency, or, at least be aware of possibilities. However, it > is not necessary to have every option already built in. A spiral groove > can > be machined later and is not a necessity for initial production. A > replaceable thrust pad insert on the well bottom, if it involves simple > drilling and tapping, should still be able to be fairly easily > incorporated. > It can be machined in after the basic initial fabrication for those who > really want it. Again for Bryce, time is of essence. Most suggestions can > be > done in the field by any competent machine shop or many hobbyists with > decent bench tools. > > Laminating the thick pieces of acrylic calls for the use of a vacuum > chamber > or vacuum pump in order that no air be trapped between laminations. I > would > advise experimenting with smaller pieces and scraps first, before > attempting > the very expensive thick stuff. The bonding agent is something like > diethylene chloride and literally melts the mating surfaces. I built a TNT > table top by laminating 1/4 inch sheets of acrylic to a total of 1 1/4 > inch > thickness and have experimented with building arm boards of laminates. It > was difficult and really impossible to do it at home without trapping > varying amounts of air between layers, even though I predrilled a number > of > holes so as to be able to bolt the assemblies together (in lieu of > clamps). > On the other hand, I have some "bulletproof" glass, actually plastic, a > built up laminate with two 1/2 inch layers and two 1/8th inch layers of > polycarbonate. Commercially made, it is optically clear. Structurally, it > is > not very strong in that it is rather flexible, so I would not recommend it > for a platter. It feels much more 'dead' than acrylic and may be > interesting > to experiment at a later date as mentioned in previous posts (if bonded to > acrylic, however, be warned that the acrylic glue causes poly to turn > cloudy: no amount of drying time will clear it). The glue used to bond the > polycarbonate is very unusual in that it is much softer than the > polycarbonate which in turn is softer than acrylic. It is spread on very > thick (1 to 2 mm) and doesn't seem to dry hard. It reminds me of a thicker > version of RTV. Personally, I would be satisfied with two inch thick > platters in the machined finish. While laminating thinner sheets may be a > cheaper option, using one thicker sheet will be cosmetically much more > pleasing and probably easier on Bryce (except for moving a 4 x 8 sheet > around for the initial rough cuts). > Flaming the machined edges will obviously change the dimensional > tolerances. > The new 'clear' Basis models have a frosted finish rather than clear to > avoid the polishing and possible dimensional changes. Like many other > acrylic platters, they employ brass plugs fitted into holes drilled at the > peripheral edges of the platter in order to increase mass. Again this can > be > done by individuals with a good drill press in the field. > > regards > > Stu > > PS. Sorry if some of this is redundant, I wrote a day and a half ago, but > forgot to push send! Subject: RE: Teres-Bearing & Platter Date: Mon, 7 Feb 2000 09:38:33 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'jhlane'; StepHydro@aol.com; briday@uswest.net; cbrady@sgi.com CC: tgmackris@vicorpinc.com; ivan@win.co.nz; Tim_Bailey@medibank.com.au; n9zes@execpc.com; BBoehler@aol.com; tbombera@pathcom.com; pboser@yahoo.com; cbrady@hobbes.denver.sgi.com; gbron@worldnet.att.net; phclark@uswest.net; dcollier@arocorp.com; evergreengc@msn.com; jepstein@shwd.com; GRANTG10@aol.com; tadgesualdo@hotmail.com; Martin.Gon@kp.org; sgoudge@cisco.com; MHuber@t-online.de; afhumphrey@idirect.com; gorkuz@yahoo.com; tmackris@earthlink.net; thomas_r_martin@apl.com; tmartin033@earthlink.net; alexmi@omneon.com; wmollard@dowco.com; GMunger@mnr.org; audiodir@gte.net; sampao@home.com; roscoe@aiko.com; Grant.Sellek@transport.sa.gov.au; ds10760@medtronic.com; wlabs@ix.netcom.com; AllenVSE@compuserve.com; zettel@libby.org Repositioning is not an issue because we're going to machine the platters after the material is laminated to the proper thickness. As has been previously mentioned, the frosted finish will mask most if not all bonding imperfections. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: jhlane [SMTP:jhlane@email.msn.com] > Sent: Friday, February 04, 2000 6:15 PM > To: StepHydro@aol.com; briday@uswest.net; cbrady@sgi.com > Cc: tgmackris@vicorpinc.com; ivan@win.co.nz; Tim_Bailey@medibank.com.au; > n9zes@execpc.com; BBoehler@aol.com; tbombera@pathcom.com; > pboser@yahoo.com; cbrady@hobbes.denver.sgi.com; gbron@worldnet.att.net; > phclark@uswest.net; dcollier@arocorp.com; evergreengc@msn.com; > jepstein@shwd.com; GRANTG10@aol.com; tadgesualdo@hotmail.com; > Martin.Gon@kp.org; sgoudge@cisco.com; MHuber@t-online.de; > afhumphrey@idirect.com; gorkuz@yahoo.com; tmackris@earthlink.net; > thomas_r_martin@apl.com; tmartin033@earthlink.net; alexmi@omneon.com; > wmollard@dowco.com; GMunger@mnr.org; audiodir@gte.net; sampao@home.com; > roscoe@aiko.com; kenschei@compuserve.com; scheike@asa.org; > Grant.Sellek@transport.sa.gov.au; ds10760@medtronic.com; > wlabs@ix.netcom.com; AllenVSE@compuserve.com; zettel@libby.org > Subject: Re: Teres-Bearing & Platter > > > << A vacuum bag press would work best here. It would ensure no > bubbles, but > > more importantly even distribution of the adhesive. With > conventional > > clamping, adhesive thickness variation and bubbles will make > for possible > > balance issues. >> > > > I think this stuff bonds too quickly for a vacuum press to > help. I also > > wonder about the possibility of building stress into the > platter that will > > cause problems later...regardless of how it is bonded. > > > > Cheers/Carron > > My first instinct, also. We're not dealing with adhesives as > much as we're dealing with solvents. No margin for > repositioning, and given the fair amount of surface runout in raw > acrylics, this is an issue in need of resolution. Further, is a > cemented bond really visually absent or will there be an uneven > appearance to it as the cement seeks the high and low spots in > the bond? > > Jon Lane > > Subject: RE: Teres-Bearing & Platter - Open Items Date: Mon, 7 Feb 2000 09:49:25 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'Thom Mackris / Joan Panzella'; Tony Bombera; Tim Bailey; Thomas Martin(w); Thomas Martin (h); Thom Mackris (w); Terry Gesualdo; Stewart Ono; Steve Zettel; Stan Goudge; Sammy Pao; Roscoe Primrose; Ron Welborne; Peter Clark; Peter Boser; Mitaru, Alex; Schei, Kenneth; Ken Schei (h); Jon Lane; Joe Druley; Jeremy Epstein (w); Ivan Anderson; Igor Kuznetsoff; Grant Sellek; Grant Gassman (h); Gon, Martin; George Munger (w); Gary Bronner; Fred Humphrey; Don Carron; David Suess; Dave Collier (w); Chris Brady; Brian Day (h); Brian Boehler; Bob Pickwoad(h); Bill Mollard; Beck, Chris; Allen Wright; Steve Brooks Right on, Thom. Ken > -----Original Message----- > From: Thom Mackris / Joan Panzella [SMTP:tmackris@earthlink.net] > Sent: Saturday, February 05, 2000 8:48 AM > To: Tony Bombera; Tim Bailey; Thomas Martin(w); Thomas Martin (h); Thom > Mackris (w); Terry Gesualdo; Stewart Ono; Steve Zettel; Stan Goudge; Sammy > Pao; Roscoe Primrose; Ron Welborne; Peter Clark; Peter Boser; Mitaru, > Alex; Ken Schei (w); Ken Schei (h); Jon Lane; Joe Druley; Jeremy Epstein > (w); Ivan Anderson; Igor Kuznetsoff; Grant Sellek; Grant Gassman (h); Gon, > Martin; George Munger (w); Gary Bronner; Fred Humphrey; Don Carron; David > Suess; Dave Collier (w); Chris Brady; Brian Day (h); Brian Boehler; Bob > Pickwoad(h); Bill Mollard; Beck, Chris; Allen Wright; Steve Brooks > Subject: Re: Teres-Bearing & Platter - Open Items > > All, > > As we were getting in the final days of solidifying the bearing and > platter > design (the first time around), Chris put together a list of issues, both > open and closed. I think it's a good idea to do the same at this point. > I > don't really see any of the following items as true issues, more as > requests > for clarification as well as for "refinements" in the design. Correct me > if > I'm wrong on this one. > > There are indeed some action items arising from these "issues", which I've > noted as best as I can. I have not plowed through the last week's > e-mails, > and so I may be missing something here. Additionally, I'm rushed to get > out > of the house at the moment, but I think this should get out as soon as > possible - not waiting until tonight. Please don't be shy with your > comments. > > Having said that, I continue to be amazed at the how the major elements of > this design have held up the the scrutiny of this highly competent group. > Let the group know if I've missed something or you have more to add. > > 1) Use of Delrin as a thrust plate: ## closed ## . > > We are using Bryce's vast experience in this area in conjunction with the > experiences of Ken and Igor with this material. Delrin is an excellent > compromise between quiet (teflon) and strong (brass/bronze) and may be the > compromise that Hartmut was looking for when he replaced his teflon plate > in > his Scheu with a hard substance. It is more than robust enough for a 15 > lb. > platter, and it is field replacable (see below). > > 2) Field replacable thrust plate: ## closed ##. > > Bryce indicates that there is no problem with a drop-in thrust plate > replacement with respect to bearing perfomrance (noise & chatter). > Replacement will require no tools other than perhaps a pencil with a piece > of "blu-tak" on the end of it to retrieve the plate from the bearing well. > I suspect that this would be done by cooling down the bearing and allowing > the differing thermal expansion coefficients to "loosen up" the fit. > > Action item: Make clear the specifics of replacing the thrust plate. > > 3) Decreasing the size of the bearing well ## closed ##. > > This must be done due to material costs. Bryce indicated that we have > specified too large of a piece of brass as far as cost threshold is > concerned. The price would jump significantly if we maintained the > current > size. We are only marginally above this dimensional threshold, and the > space needs to be recoverd by sacrificing part of the bearing well. Igor > would like to have as much oil damping as possible and suggested that some > of the well volume be recovered by "necking down" the bearing shaft. > Bryce > indicated that this would compromise the excellent tolerances he expects > to > attain on the shaft. These tolerances are attributable to the thickiness > (and hence rigidity) of the shaft. To date, we've had no one question > that > the #1 priority is to machine the absolute best tolerances possible. > > 4) Use of three layers of acrylic for platter ## closed ## > > Action items: > (4a) We need to confirm that the glue will ensure a good weld, that is > cosmetically and structurally acceptable with respect to the platter > having > a machined finish. > > (4b) We may learn that Bryce will need to subcontract out the task of > making > 3" thick blanks to work from. > > I have to sign off ... there may be more, but this will certainly get us > started. > > Thanks for your feedback, > Thom > > > > Subject: Re: RE: Teres-Bearing & Platter - Open Items Date: Mon, 7 Feb 2000 10:08:56 -0700 From: George Munger, George Munger To: roscoe@aiko.com; BBoehler@aol.com; GRANTG10@aol.com; StepHydro@aol.com; thomas_r_martin@apl.com; dcollier@arocorp.com; SCHEIKE@asa.org; brookss@bellsouth.net; sgoudge@cisco.com; AllenVSE@compuserve.com; kenschei@compuserve.com; wmollard@dowco.com; tmackris@earthlink.net; tmartin033@earthlink.net; jhlane@email.msn.com; n9zes@execpc.com; audiodir@gte.net; sampao@home.com; tadgesualdo@hotmail.com; afhumphrey@idirect.com; wlabs@ix.netcom.com; Martin.Gon@kp.org; zettel@libby.org; grafique@mciworld.com; Tim_Bailey@medibank.com.au; ds10760@medtronic.com; evergreengc@msn.com; alexmi@omneon.com; tbombera@pathcom.com; cbrady@sgi.com; jepstein@shwd.com; Grant.Sellek@transport.sa.gov.au; briday@uswest.net; phclark@uswest.net; thom.mackris@vicorpinc.com; ivan@win.co.nz; gbron@worldnet.att.net; gorkuz@yahoo.com; pboser@yahoo.com Maybe, if others agree and not already done (please forgive me if I missed it), add an action item to nail down labor and material costs for item #4 acrylic layers & bonding. GM >>> "Schei, Kenneth" 02/07 10:51 AM >>> Right on, Thom. Ken > -----Original Message----- > From: Thom Mackris / Joan Panzella [SMTP:tmackris@earthlink.net] > Sent: Saturday, February 05, 2000 8:48 AM > To: Tony Bombera; Tim Bailey; Thomas Martin(w); Thomas Martin (h); Thom > Mackris (w); Terry Gesualdo; Stewart Ono; Steve Zettel; Stan Goudge; Sammy > Pao; Roscoe Primrose; Ron Welborne; Peter Clark; Peter Boser; Mitaru, > Alex; Ken Schei (w); Ken Schei (h); Jon Lane; Joe Druley; Jeremy Epstein > (w); Ivan Anderson; Igor Kuznetsoff; Grant Sellek; Grant Gassman (h); Gon, > Martin; George Munger (w); Gary Bronner; Fred Humphrey; Don Carron; David > Suess; Dave Collier (w); Chris Brady; Brian Day (h); Brian Boehler; Bob > Pickwoad(h); Bill Mollard; Beck, Chris; Allen Wright; Steve Brooks > Subject: Re: Teres-Bearing & Platter - Open Items > > All, > > As we were getting in the final days of solidifying the bearing and > platter > design (the first time around), Chris put together a list of issues, both > open and closed. I think it's a good idea to do the same at this point. > I > don't really see any of the following items as true issues, more as > requests > for clarification as well as for "refinements" in the design. Correct me > if > I'm wrong on this one. > > There are indeed some action items arising from these "issues", which I've > noted as best as I can. I have not plowed through the last week's > e-mails, > and so I may be missing something here. Additionally, I'm rushed to get > out > of the house at the moment, but I think this should get out as soon as > possible - not waiting until tonight. Please don't be shy with your > comments. > > Having said that, I continue to be amazed at the how the major elements of > this design have held up the the scrutiny of this highly competent group. > Let the group know if I've missed something or you have more to add. > > 1) Use of Delrin as a thrust plate: ## closed ## . > > We are using Bryce's vast experience in this area in conjunction with the > experiences of Ken and Igor with this material. Delrin is an excellent > compromise between quiet (teflon) and strong (brass/bronze) and may be the > compromise that Hartmut was looking for when he replaced his teflon plate > in > his Scheu with a hard substance. It is more than robust enough for a 15 > lb. > platter, and it is field replacable (see below). > > 2) Field replacable thrust plate: ## closed ##. > > Bryce indicates that there is no problem with a drop-in thrust plate > replacement with respect to bearing perfomrance (noise & chatter). > Replacement will require no tools other than perhaps a pencil with a piece > of "blu-tak" on the end of it to retrieve the plate from the bearing well. > I suspect that this would be done by cooling down the bearing and allowing > the differing thermal expansion coefficients to "loosen up" the fit. > > Action item: Make clear the specifics of replacing the thrust plate. > > 3) Decreasing the size of the bearing well ## closed ##. > > This must be done due to material costs. Bryce indicated that we have > specified too large of a piece of brass as far as cost threshold is > concerned. The price would jump significantly if we maintained the > current > size. We are only marginally above this dimensional threshold, and the > space needs to be recoverd by sacrificing part of the bearing well. Igor > would like to have as much oil damping as possible and suggested that some > of the well volume be recovered by "necking down" the bearing shaft. > Bryce > indicated that this would compromise the excellent tolerances he expects > to > attain on the shaft. These tolerances are attributable to the thickiness > (and hence rigidity) of the shaft. To date, we've had no one question > that > the #1 priority is to machine the absolute best tolerances possible. > > 4) Use of three layers of acrylic for platter ## closed ## > > Action items: > (4a) We need to confirm that the glue will ensure a good weld, that is > cosmetically and structurally acceptable with respect to the platter > having > a machined finish. > > (4b) We may learn that Bryce will need to subcontract out the task of > making > 3" thick blanks to work from. > > I have to sign off ... there may be more, but this will certainly get us > started. > > Thanks for your feedback, > Thom > > > > Subject: RE: Teres-Bearing & Platter Date: Mon, 7 Feb 2000 14:52:06 -0700 From: Martin Gon, Martin Gon To: tgmackris CC: ivan; Tim_Bailey; n9zes; BBoehler; tbombera; pboser; cbrady; gbron; StepHydro; phclark; dcollier; briday; evergreengc; jepstein; grantg10; tadgesualdo; sgoudge; MHuber; afhumphrey; gorkuz; jhlane; tmackris; thomas_r_martin; tmartin033; alexmi; wmollard; GMunger; audiodir; sampao; roscoe; kenschei; scheike; Grant.Sellek; ds10760; wlabs; AllenVSE; zettel Gang, I second Jon Lane's ideas regarding a flat end of the spindle. Delrin, or perhaps nitrile rubber ( whhich are used as seals for car engines ) maybe used as a thrust pad at the bottom of the spindle well. The lubricant as a thin oil layer versus Dow silcone fluid 200 could be used to aid in the loss of vibrational energy via drag. The Platine Verdier I believe uses magnetic drag to provide this lossiness. I had mentioned to Thom Makris an interesting interview in a 1987 Stereophile(anyone still have a copy of this?) with William Firebaugh, the inventor/designer of theWell Tempered Table. I think if someone has this article an could scan it for the Group may be worthwhile reading (I can't find mine at this time) as well as the articles from Sound Practices as previously mentioned Martin. Subject: RE: Teres-Bearing & Platter Date: Mon, 7 Feb 2000 16:58:00 -0700 From: Mackris, Thom G., Mackris, Thom G. To: Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Schei (h), Ken; Schei (w), Ken; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve Hi Martin, Jon Both of your posts are provocative and really get me to thinking, but in the end I strongly believe that your proposals have the potential to limit our lubrication choices as well as to degrade the overall performance of the bearing. When we put this design out to the greater Joe List community we were indeed soliciting suggestions, comments, and the possibility of enhancing the design for the greater analog good. There are now 5 digests out there representing a compilation of over 250 e-mails on the bearing and platter design. The first four digests are a compilation of the dialog up to the time I posted the announcement to the Joe List. The rationale for our bearing is explained quite well there. At the risk of boring everyone who has absorbed these digests, let me re-state that Delrin is *extremely* tough stuff. It's used in race car suspension bushings. I owned a bicycle in 1968 that had it's rear derailleur made of delrin. I'm not certain how you equate delrin with nitrile rubber. Perhaps this was not your intent, and you were mentioning a range of materials to be tried from hard (delrin) to lossy (rubber). The common knowledge in the area of thrust bearing design is to sink vibrations from the bearing into the subchassis. I don't see how nitrile rubber will accomplish this. One of the weaknesses of the Verdier (in comparison with the Scheu) is that the magnetic suspension of the Verdier is thought to kill bass response. Granted, this is a bit of pontification on the part of the people who have posted this to the Joe List, but my main point here is that the Scheu is a very strong design and I'm not in the least bit inclined to deviate from a ball bearing thrust delrin pad approach based on the success that many have had with this approach. Additionally, I personally have a problem with designing a thrust bearing which is totally dependent on lubrication technology in order to make it float. We are designing state of the art tolerances in this bearing and the possibility exists that the viscosity required to float the thrust plate in your proposed design will not work with the tolerances we are machining. In the digests, we had extensive discussions about oil viscosity and how we will determine what oil to use. The conclusion was to machine the best bearing we could, and to experiment with viscosities. Your design would compromise our ability to do so. Thomas Scheu among others are strong advocates of extremely thin oil. While it is indeed possible that your idea is superior from a thrust plate perspective it could end up limiting our lubrication choices with respect to optimizing the bearing's performance as a whole. The Well Tempered is a unique and imaginative design and I have not read the Stereophile article you reference in over 10 years. Last year I did a "spiritual cleansing" and disposed of all of my Stereophiles and Absolute Sounds. Ron Welborne is an advocate of this turntable and his 'table certainly is a good performer, as is my Merrill. I want more. A major weakness in the Well Tempered bearing as well as in most conventional, non-inverted bearings is addressed by our design - limiting the teeter totering of the platter. In the case of the Well Tempered, the bearing is located by the belt! It's bearing is most certainly quiet, but I want more stability than this bearing offers & hence our low center of gravity design. Keep 'em coming ... Cheers, Thom -----Original Message----- From: Martin Gon [mailto:Martin.Gon@kp.org] Sent: Monday, February 07, 2000 10:57 AM Subject: RE: Teres-Bearing & Platter Gang, I second Jon Lane's ideas regarding a flat end of the spindle. Delrin, or perhaps nitrile rubber ( whhich are used as seals for car engines ) maybe used as a thrust pad at the bottom of the spindle well. The lubricant as a thin oil layer versus Dow silcone fluid 200 could be used to aid in the loss of vibrational energy via drag. The Platine Verdier I believe uses magnetic drag to provide this lossiness. I had mentioned to Thom Makris an interesting interview in a 1987 Stereophile(anyone still have a copy of this?) with William Firebaugh, the inventor/designer of theWell Tempered Table. I think if someone has this article an could scan it for the Group may be worthwhile reading (I can't find mine at this time) as well as the articles from Sound Practices as previously mentioned Martin. Subject: RE: Teres-Bearing & Platter Date: Mon, 7 Feb 2000 17:50:56 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'Mackris, Thom G.'; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve There have been a lot of questions in the past regarding the use of a Delrin bearing pad. Most of these questions seem to stem from the conception that Delrin may be too soft for the intended purpose. Delrin is a DuPont trade name for acetyl plastic. It is extremely tough and one of its most recommended applications is for bearing components. In bearing applications it will outwear nylon by a factor of 4. The two most important characteristics of Delrin for our use are its natural lubricity and its surface hardness. Surface hardness is commonly measured by a durometer test, which measures the indentation by a calibrated probe. Delrin actually has a greater surface hardness than brass, which is another common bearing material. In our application, Delrin would be harder and more slippery than brass. If we wanted to discard Delrin as a bearing pad, it would be more likely because it was too hard, not too soft. I believe Delrin is the ideal material for our bearing pad. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Mackris, Thom G. [SMTP:tgmackris@vicorpinc.com] > Sent: Monday, February 07, 2000 3:46 PM > To: Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, > Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, > Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), > Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; > Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), > Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, > Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; > Pickwoad (h), Bob; Primrose, Roscoe; Schei (h), Ken; Schei (w), Ken; > Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve > Subject: RE: Teres-Bearing & Platter > > Hi Martin, Jon > > Both of your posts are provocative and really get me to thinking, but in > the > end I strongly believe that your proposals have the potential to limit our > lubrication choices as well as to degrade the overall performance of the > bearing. > > When we put this design out to the greater Joe List community we were > indeed > soliciting suggestions, comments, and the possibility of enhancing the > design for the greater analog good. There are now 5 digests out there > representing a compilation of over 250 e-mails on the bearing and platter > design. The first four digests are a compilation of the dialog up to the > time I posted the announcement to the Joe List. The rationale for our > bearing is explained quite well there. > > At the risk of boring everyone who has absorbed these digests, let me > re-state that Delrin is *extremely* tough stuff. It's used in race car > suspension bushings. I owned a bicycle in 1968 that had it's rear > derailleur made of delrin. I'm not certain how you equate delrin with > nitrile rubber. Perhaps this was not your intent, and you were mentioning > a > range of materials to be tried from hard (delrin) to lossy (rubber). > > The common knowledge in the area of thrust bearing design is to sink > vibrations from the bearing into the subchassis. I don't see how nitrile > rubber will accomplish this. One of the weaknesses of the Verdier (in > comparison with the Scheu) is that the magnetic suspension of the Verdier > is > thought to kill bass response. Granted, this is a bit of pontification on > the part of the people who have posted this to the Joe List, but my main > point here is that the Scheu is a very strong design and I'm not in the > least bit inclined to deviate from a ball bearing thrust delrin pad > approach > based on the success that many have had with this approach. > > Additionally, I personally have a problem with designing a thrust bearing > which is totally dependent on lubrication technology in order to make it > float. We are designing state of the art tolerances in this bearing and > the > possibility exists that the viscosity required to float the thrust plate > in > your proposed design will not work with the tolerances we are machining. > > In the digests, we had extensive discussions about oil viscosity and how > we > will determine what oil to use. The conclusion was to machine the best > bearing we could, and to experiment with viscosities. Your design would > compromise our ability to do so. Thomas Scheu among others are strong > advocates of extremely thin oil. While it is indeed possible that your > idea > is superior from a thrust plate perspective it could end up limiting our > lubrication choices with respect to optimizing the bearing's performance > as > a whole. > > The Well Tempered is a unique and imaginative design and I have not read > the > Stereophile article you reference in over 10 years. Last year I did a > "spiritual cleansing" and disposed of all of my Stereophiles and Absolute > Sounds. Ron Welborne is an advocate of this turntable and his 'table > certainly is a good performer, as is my Merrill. I want more. A major > weakness in the Well Tempered bearing as well as in most conventional, > non-inverted bearings is addressed by our design - limiting the teeter > totering of the platter. In the case of the Well Tempered, the bearing is > located by the belt! It's bearing is most certainly quiet, but I want > more > stability than this bearing offers & hence our low center of gravity > design. > > Keep 'em coming ... > > Cheers, > Thom > > -----Original Message----- > From: Martin Gon [mailto:Martin.Gon@kp.org] > Sent: Monday, February 07, 2000 10:57 AM > Subject: RE: Teres-Bearing & Platter > > > Gang, > I second Jon Lane's ideas regarding a flat end of the spindle. Delrin, or > perhaps nitrile rubber ( whhich are used as seals for car engines ) maybe > used as a thrust pad at the bottom of the spindle well. The lubricant as a > thin oil layer versus Dow silcone fluid 200 could be used to aid in the > loss > of vibrational energy via drag. The Platine Verdier I believe uses > magnetic > drag to provide this lossiness. I had mentioned to Thom Makris an > interesting interview in a 1987 Stereophile(anyone still have a copy of > this?) with William Firebaugh, the inventor/designer of theWell Tempered > Table. I think if someone has this article an could scan it for the Group > may be worthwhile reading (I can't find mine at this time) as well as the > articles from Sound Practices as previously mentioned > > Martin. Subject: Re: Teres-Bearing & Platter Date: Mon, 7 Feb 2000 18:09:14 -0700 From: root, root To: Mackris, Thom G. CC: Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Schei (h), Ken; Schei (w), Ken; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve There has been some discussion on the bearing and platter design that I need to comment on. Forgive the delayed response but I have been a bit busy. 1) Lamination of the platter. I discussed this issue with Bryce and he had already concluded that vacuum bagging would be the best way to do the lamination (as usual a step ahead of us). Bryce is also negotiating a price with a local plastic supplier to do the rough cutting and laminating of the acrylic. Regardless of who ends up doing the lamination we can be certain that the platters will be stable accurate, balanced, etc. However, there will be a possibility of small bubbles in the joints. The cost of making the platters from 3" material is extremely high and is not being considered for the group purchase. 2) Platter finish. The finish that is planned for the platters is simply what we have after the machining is complete. The appearance will be a smooth "frosty" look that I expect will be quite attractive. We will all be free to do additional finishing (bead blasting, polishing) but this will not be done by Bryce. 3) The package will include the following: - 3" acrylic platter - Brass bearing body - Stainless steel bearing spindle with a bearing pressed into the end - 2 threaded inserts (one smooth on the top and one threaded on both ends) - A delrin thrust plate - 1-1/8" nut that has been split to provide a lower 1/2" height. 4) Price. There is good and bad news regarding the price. The bad news is that Bryce discovered that his calculations for the platter price were for a 2" thick platter. This has a small impact on labor, but a big impact on material cost. But the good news is that we now have commitments for more than 20 units. With 20+ units the volume discount will make up for the additional material costs. Hiring out the acrylic cutting and lamination will probably have a small impact on the price, but we don't know if it will be more or less. Chris Subject: Re: Teres-Bearing & Platter Date: Mon, 7 Feb 2000 20:34:59 -0700 From: Jon Lane [h], Jon Lane [h] To: Schei, Kenneth; 'Mackris, Thom G.'; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve > There have been a lot of questions in the past regarding the use of a Delrin > bearing pad. Most of these questions seem to stem from the conception that > Delrin may be too soft for the intended purpose. Delrin is a DuPont trade > name for acetyl plastic. It is extremely tough and one of its most > recommended applications is for bearing components. In bearing applications > it will outwear nylon by a factor of 4. The two most important > characteristics of Delrin for our use are its natural lubricity and its > surface hardness. Surface hardness is commonly measured by a durometer > test, which measures the indentation by a calibrated probe. Delrin actually > has a greater surface hardness than brass, which is another common bearing > material. In our application, Delrin would be harder and more slippery than > brass. If we wanted to discard Delrin as a bearing pad, it would be more > likely because it was too hard, not too soft. I believe Delrin is the ideal > material for our bearing pad. > > Ken Good post, Ken, you've summed up the advantages of Delrin perfectly. In fact, this material is specifically intended as a bearing surface... I think the only point against Delrin would be argued for another reason entirely. That is, not that Delrin is a poor bearing with finite wear capability, but that it could be improved on in the areas of noise and the transmission of such. Many 'tables have specifically been designed with means of mechanical coupling, of which perhaps the Goldmund was, when it appeared, the most notable. These designs relied on extremely hard bearings to complete the mechanical ground between components. The thinking, apparently, was that micro-information could only be retrieved by extreme coupling and the mechanical grounding of vibration. Given the successes of everything from the Linn thru SOTA even to today's better sounding designs, this concept has been proven time and again. Personally, I am going to experiment with a carbide ball and jeweled thrust plate right off in my Teres. There is no doubt in my mind but that the differences between hard and relatively soft interfaces at this critical location will indeed be audible, even if the subjective preferences will probably vary all over the map. It should be an interesting experiment. While I did once build a Delrin-bearing 'table, and it was reasonably good, I also fear for the long-term variability as the Delrin deforms to the extreme pressure presented by a heavy platter through a point contact area. As the Delrin "cups" imperceptibly (just as brass would over time, to use your example) the mechanical sinking will also vary and the possibility for minute amounts of frictional noise to creep into the system may rise. Again, the sonic result is hard to predict but is still likely to be audible as the pieces wear in. One last comment: The Oracle and, I think, the Linn both use hard thrust surfaces but rather cheap sleeve bearings. The Oracle used a manufactured sleeve of bearing plastic in a metal shell in two places and I think the Linn may also. In this regard, I expect the Teres to be far superior. Its likely that the machined female part of the Teres will be to a far tighter tolerance. Jon Lane Subject: RE: Teres-Bearing & Platter Date: Tue, 8 Feb 2000 01:56:49 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'jhlane'; StepHydro@aol.com; briday@uswest.net; cbrady@sgi.com CC: tgmackris@vicorpinc.com; ivan@win.co.nz; Tim_Bailey@medibank.com.au; n9zes@execpc.com; BBoehler@aol.com; tbombera@pathcom.com; pboser@yahoo.com; cbrady@hobbes.denver.sgi.com; gbron@worldnet.att.net; phclark@uswest.net; dcollier@arocorp.com; evergreengc@msn.com; jepstein@shwd.com; GRANTG10@aol.com; tadgesualdo@hotmail.com; Martin.Gon@kp.org; sgoudge@cisco.com; MHuber@t-online.de; afhumphrey@idirect.com; gorkuz@yahoo.com; tmackris@earthlink.net; thomas_r_martin@apl.com; tmartin033@earthlink.net; alexmi@omneon.com; wmollard@dowco.com; GMunger@mnr.org; audiodir@gte.net; sampao@home.com; roscoe@aiko.com; Grant.Sellek@transport.sa.gov.au; ds10760@medtronic.com; wlabs@ix.netcom.com; AllenVSE@compuserve.com; zettel@libby.org Repositioning is not an issue because we're going to machine the platters after the material is laminated to the proper thickness. As has been previously mentioned, the frosted finish will mask most if not all bonding imperfections. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: jhlane [SMTP:jhlane@email.msn.com] > Sent: Friday, February 04, 2000 6:15 PM > To: StepHydro@aol.com; briday@uswest.net; cbrady@sgi.com > Cc: tgmackris@vicorpinc.com; ivan@win.co.nz; Tim_Bailey@medibank.com.au; > n9zes@execpc.com; BBoehler@aol.com; tbombera@pathcom.com; > pboser@yahoo.com; cbrady@hobbes.denver.sgi.com; gbron@worldnet.att.net; > phclark@uswest.net; dcollier@arocorp.com; evergreengc@msn.com; > jepstein@shwd.com; GRANTG10@aol.com; tadgesualdo@hotmail.com; > Martin.Gon@kp.org; sgoudge@cisco.com; MHuber@t-online.de; > afhumphrey@idirect.com; gorkuz@yahoo.com; tmackris@earthlink.net; > thomas_r_martin@apl.com; tmartin033@earthlink.net; alexmi@omneon.com; > wmollard@dowco.com; GMunger@mnr.org; audiodir@gte.net; sampao@home.com; > roscoe@aiko.com; kenschei@compuserve.com; scheike@asa.org; > Grant.Sellek@transport.sa.gov.au; ds10760@medtronic.com; > wlabs@ix.netcom.com; AllenVSE@compuserve.com; zettel@libby.org > Subject: Re: Teres-Bearing & Platter > > > << A vacuum bag press would work best here. It would ensure no > bubbles, but > > more importantly even distribution of the adhesive. With > conventional > > clamping, adhesive thickness variation and bubbles will make > for possible > > balance issues. >> > > > I think this stuff bonds too quickly for a vacuum press to > help. I also > > wonder about the possibility of building stress into the > platter that will > > cause problems later...regardless of how it is bonded. > > > > Cheers/Carron > > My first instinct, also. We're not dealing with adhesives as > much as we're dealing with solvents. No margin for > repositioning, and given the fair amount of surface runout in raw > acrylics, this is an issue in need of resolution. Further, is a > cemented bond really visually absent or will there be an uneven > appearance to it as the cement seeks the high and low spots in > the bond? > > Jon Lane > > Subject: RE: Teres-Bearing & Platter Date: Tue, 8 Feb 2000 08:52:38 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'Jon Lane [h]'; 'Mackris, Thom G.'; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve Jon: Thanks for the valuable input - your points are well thought out and quite interesting. Since the delrin bearing is removable, we have the options to make modifications just as you plan to do. Where can you obtain a jeweled thrust plate and how much would one cost? I may want to experiment with one myself. One of my other interests is old Swiss watches, which of course use jewels (synthetic rubys) for bearings, but mainly for extended wear-resistance, rather than any audible reasons, although a fine Swiss watch sounds much smoother than a cheaper one. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Jon Lane [h] [SMTP:jhlane@email.msn.com] > Sent: Monday, February 07, 2000 7:23 PM > To: Schei, Kenneth; 'Mackris, Thom G.'; Anderson, Ivan; Bailey, Tim; > Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; > Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), > Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, > Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; > Kuznetsoff, Igor; Mackris (h), Thom; Martin (w), Thomas; Martin(h), > Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), > George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; > Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve > Subject: Re: Teres-Bearing & Platter > > > There have been a lot of questions in the past regarding the > use of a Delrin > > bearing pad. Most of these questions seem to stem from the > conception that > > Delrin may be too soft for the intended purpose. Delrin is a > DuPont trade > > name for acetyl plastic. It is extremely tough and one of its > most > > recommended applications is for bearing components. In bearing > applications > > it will outwear nylon by a factor of 4. The two most important > > characteristics of Delrin for our use are its natural lubricity > and its > > surface hardness. Surface hardness is commonly measured by a > durometer > > test, which measures the indentation by a calibrated probe. > Delrin actually > > has a greater surface hardness than brass, which is another > common bearing > > material. In our application, Delrin would be harder and more > slippery than > > brass. If we wanted to discard Delrin as a bearing pad, it > would be more > > likely because it was too hard, not too soft. I believe Delrin > is the ideal > > material for our bearing pad. > > > > Ken > > Good post, Ken, you've summed up the advantages of Delrin > perfectly. In fact, this material is specifically intended as a > bearing surface... > > I think the only point against Delrin would be argued for another > reason entirely. That is, not that Delrin is a poor bearing with > finite wear capability, but that it could be improved on in the > areas of noise and the transmission of such. > > Many 'tables have specifically been designed with means of > mechanical coupling, of which perhaps the Goldmund was, when it > appeared, the most notable. These designs relied on extremely > hard bearings to complete the mechanical ground between > components. The thinking, apparently, was that micro-information > could only be retrieved by extreme coupling and the mechanical > grounding of vibration. Given the successes of everything from > the Linn thru SOTA even to today's better sounding designs, this > concept has been proven time and again. > > Personally, I am going to experiment with a carbide ball and > jeweled thrust plate right off in my Teres. There is no doubt in > my mind but that the differences between hard and relatively soft > interfaces at this critical location will indeed be audible, even > if the subjective preferences will probably vary all over the > map. It should be an interesting experiment. > > While I did once build a Delrin-bearing 'table, and it was > reasonably good, I also fear for the long-term variability as the > Delrin deforms to the extreme pressure presented by a heavy > platter through a point contact area. As the Delrin "cups" > imperceptibly (just as brass would over time, to use your > example) the mechanical sinking will also vary and the > possibility for minute amounts of frictional noise to creep into > the system may rise. Again, the sonic result is hard to predict > but is still likely to be audible as the pieces wear in. > > One last comment: The Oracle and, I think, the Linn both use > hard thrust surfaces but rather cheap sleeve bearings. The > Oracle used a manufactured sleeve of bearing plastic in a metal > shell in two places and I think the Linn may also. In this > regard, I expect the Teres to be far superior. Its likely that > the machined female part of the Teres will be to a far tighter > tolerance. > > Jon Lane > > Subject: RE: Teres-Bearing & Platter Date: Tue, 8 Feb 2000 09:38:21 -0700 From: Mackris, Thom G., Mackris, Thom G. To: 'Jon Lane [h]'; Schei, Kenneth; Mackris, Thom G.; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve It sounds as if the area of flexibility with respect to the changable thrust plate resolves this issue. I love the overall flexibility of this design and opporunity for tweaking that this provides... something that probably would not have occurred if there were only one or two people involved. It seems as if we have one remaining action item in this area: to clarify with Bryce how the Delrin thrust plate can be removed. - Will it just drop out by turning the bearing uside down? - Will a little cooling be required (differential contraction of the brass vs delrin) in order to allow it to fall out? Tonight, I will re-summarize where the design sits (all substantial issues are closed, IMHO). And remaining action items such as the one above, as well as what we can expect from the cosmetics of the platter. With respect to cosmetics, I'm hoping that we can present a worst case scenario so that all surprises are pleasant ones. Cheers, Thom -----Original Message----- From: Jon Lane [h] [mailto:jhlane@email.msn.com] Sent: Monday, February 07, 2000 7:23 PM Subject: Re: Teres-Bearing & Platter Good post, Ken, you've summed up the advantages of Delrin perfectly. In fact, this material is specifically intended as a bearing surface... I think the only point against Delrin would be argued for another reason entirely. That is, not that Delrin is a poor bearing with finite wear capability, but that it could be improved on in the areas of noise and the transmission of such. Many 'tables have specifically been designed with means of mechanical coupling, of which perhaps the Goldmund was, when it appeared, the most notable. These designs relied on extremely hard bearings to complete the mechanical ground between components. The thinking, apparently, was that micro-information could only be retrieved by extreme coupling and the mechanical grounding of vibration. Given the successes of everything from the Linn thru SOTA even to today's better sounding designs, this concept has been proven time and again. Personally, I am going to experiment with a carbide ball and jeweled thrust plate right off in my Teres. There is no doubt in my mind but that the differences between hard and relatively soft interfaces at this critical location will indeed be audible, even if the subjective preferences will probably vary all over the map. It should be an interesting experiment. While I did once build a Delrin-bearing 'table, and it was reasonably good, I also fear for the long-term variability as the Delrin deforms to the extreme pressure presented by a heavy platter through a point contact area. As the Delrin "cups" imperceptibly (just as brass would over time, to use your example) the mechanical sinking will also vary and the possibility for minute amounts of frictional noise to creep into the system may rise. Again, the sonic result is hard to predict but is still likely to be audible as the pieces wear in. One last comment: The Oracle and, I think, the Linn both use hard thrust surfaces but rather cheap sleeve bearings. The Oracle used a manufactured sleeve of bearing plastic in a metal shell in two places and I think the Linn may also. In this regard, I expect the Teres to be far superior. Its likely that the machined female part of the Teres will be to a far tighter tolerance. Jon Lane Subject: RE: Teres-Bearing & Platter Date: Tue, 8 Feb 2000 10:00:23 -0700 From: Mackris, Thom G., Mackris, Thom G. To: Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Schei (h), Ken; Schei (w), Ken; Sellek, Grant; Suess, David; Welborne, Ron; Zettell, Steve Jon, Your question is definitely an action item that we need to answer in the next couple of days. Perhaps answering this question will delay our time schedule by a week or so. I don't know, as Chris is the one who is working with Bryce. We have an obligation to all of you to obtain the best possible information, in order to make an informed purchase decision. The last thing anyone wants to do is to raise expections beyond what is possible. I trust that everyone recognizes that this is a hobbyest venture. There is no startup money as such for which to run prototypes in order to inspect the bonding. Is this important enough to consider a step in the process? I don't think so, but your comments are welcome. To put things into perspective, let me paraphrase a comment that was made to me privately. Anyone who wants cosmetic perfection should buy a Verdier and deal with the loan payments and the inferior sound :-)) Seriously though, you can tell from looking at Chris' web site that he has a high standard for the appearance of his projects. They look better in person! It still remains to be seen how perfect these platters will look with respect to bubbles. Cheers, Thom -----Original Message----- From: Jon Lane [h] [mailto:jhlane@email.msn.com] Subject: Re: Teres-Bearing & Platter > As has been previously mentioned, the frosted finish will mask most if not all bonding > imperfections. I've added my order to the list but this is my only point of concern. Machining will NOT hide internal blemishes unless the machining marks are quite harsh. I've built plexi platters and even through the surface lathe marks the opposite sides are quite visible... And the option of polishing the surfaces should be left open, if possible. Is this point open to a test? Jon Lane Subject: RE: Teres-Bearing & Platter Date: Tue, 8 Feb 2000 13:40:15 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: Schei, Kenneth; 'Jon Lane [h]'; 'Mackris, Thom G.'; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve Jon, Ken, These are interesting comments. I too am curious about where Carbide balls and jeweled thrust plates can be obtained from and cost. The jeweling is, if I understand correctly, a close relative of Ruby by way of (both) being an aluminun oxide with various trace elements. Aluminum oxide is, of course, extremely hard, which is why it is used in making sandpaper, among other things. My concern with using carbide on aluminum oxide would be with how quietly the two would interact. I had the good fortune to spend some hours listening to and playing with the Goldmund TT at Listen Up in Boulder back during the '80's, when I lived in Vail. An interesting & complicated machine, for that time. One of the things I was *not* impressed with was a quiet noise floor. To be sure, I have no way of determining the cause for this, I did not play with enough of that audio chain to to pin that down, only swapped the amps & some interconnects around. Still, I remember this about that rig well enough for it to have come to mind. There is no doubt that there is likely to be an audible difference between the Delrin and the Carbide/Alumina combination, though which is superior, and to whose tastes, would be a try it and hear. The nice thing about our design is that these & others can be tried interchangeably. Ken, do you have the Rockwell (hardness) numbers available for these materials, as well as Brass, for a curiousity satisfying comparison? --- "Schei, Kenneth" wrote: > Jon: > > Thanks for the valuable input - your points are well > thought out and quite > interesting. Since the delrin bearing is removable, > we have the options to > make modifications just as you plan to do. Where > can you obtain a jeweled > thrust plate and how much would one cost? I may > want to experiment with one > myself. One of my other interests is old Swiss > watches, which of course use > jewels (synthetic rubys) for bearings, but mainly > for extended > wear-resistance, rather than any audible reasons, > although a fine Swiss > watch sounds much smoother than a cheaper one. > > Ken > > Ken Schei, P.E. > Project Engineer > Antarctic Support Associates > Email address: scheike@asa.org > Phone: 303-643-0163 > > > -----Original Message----- > > From: Jon Lane [h] [SMTP:jhlane@email.msn.com] > > Sent: Monday, February 07, 2000 7:23 PM > > To: Schei, Kenneth; 'Mackris, Thom G.'; Anderson, > Ivan; Bailey, Tim; > > Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, > Peter; Brady, Chris; > > Bronner, Gary; Carron, Don; Clark, Peter; Collier > (w), Dave; Day (h), > > Brian; Druley, Joe; Epstein (w), Jeremy; Gassman > (h), Grant; Gesualdo, > > Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; > Humphrey, Fred; > > Kuznetsoff, Igor; Mackris (h), Thom; Martin (w), > Thomas; Martin(h), > > Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, > William; Munger (w), > > George; Ono, Stewart; Pao, Sammy; Pickwoad (h), > Bob; Primrose, Roscoe; > > Sellek, Grant; Suess, David; Welborne, Ron; > Wright, Allen; Zettell, Steve > > Subject: Re: Teres-Bearing & Platter > > > > > There have been a lot of questions in the past > regarding the > > use of a Delrin > > > bearing pad. Most of these questions seem to > stem from the > > conception that > > > Delrin may be too soft for the intended purpose. > Delrin is a > > DuPont trade > > > name for acetyl plastic. It is extremely tough > and one of its > > most > > > recommended applications is for bearing > components. In bearing > > applications > > > it will outwear nylon by a factor of 4. The two > most important > > > characteristics of Delrin for our use are its > natural lubricity > > and its > > > surface hardness. Surface hardness is commonly > measured by a > > durometer > > > test, which measures the indentation by a > calibrated probe. > > Delrin actually > > > has a greater surface hardness than brass, which > is another > > common bearing > > > material. In our application, Delrin would be > harder and more > > slippery than > > > brass. If we wanted to discard Delrin as a > bearing pad, it > > would be more > > > likely because it was too hard, not too soft. I > believe Delrin > > is the ideal > > > material for our bearing pad. > > > > > > Ken > > > > Good post, Ken, you've summed up the advantages of > Delrin > > perfectly. In fact, this material is specifically > intended as a > > bearing surface... > > > > I think the only point against Delrin would be > argued for another > > reason entirely. That is, not that Delrin is a > poor bearing with > > finite wear capability, but that it could be > improved on in the > > areas of noise and the transmission of such. > > > > Many 'tables have specifically been designed with > means of > > mechanical coupling, of which perhaps the Goldmund > was, when it > > appeared, the most notable. These designs relied > on extremely > > hard bearings to complete the mechanical ground > between > > components. The thinking, apparently, was that > micro-information > > could only be retrieved by extreme coupling and > the mechanical > > grounding of vibration. Given the successes of > everything from > > the Linn thru SOTA even to today's better sounding > designs, this > > concept has been proven time and again. > > > > Personally, I am going to experiment with a > carbide ball and > > jeweled thrust plate right off in my Teres. There > is no doubt in > > my mind but that the differences between hard and > relatively soft > > interfaces at this critical location will indeed > be audible, even > > if the subjective preferences will probably vary > all over the > > map. It should be an interesting experiment. > > > > While I did once build a Delrin-bearing 'table, > and it was > > reasonably good, I also fear for the long-term > variability as the > > Delrin deforms to the extreme pressure presented > by a heavy > > platter through a point contact area. As the > Delrin "cups" > > imperceptibly (just as brass would over time, to > use your > > example) the mechanical sinking will also vary and > the > > possibility for minute amounts of frictional noise > to creep into > > the system may rise. Again, the sonic result is > hard to predict > > but is still likely to be audible as the pieces > wear in. > > > > One last comment: The Oracle and, I think, the > Linn both use > > hard thrust surfaces but rather cheap sleeve > bearings. The > > Oracle used a manufactured sleeve of bearing > plastic in a metal > > shell in two places and I think the Linn may also. > In this > > regard, I expect the Teres to be far superior. > Its likely that > > the machined female part of the Teres will be to a > far tighter > > tolerance. > > > > Jon Lane > > > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: RE: Teres-Bearing & Platter Date: Tue, 8 Feb 2000 15:41:55 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'Igor Kuznetsoff'; 'Jon Lane [h]'; 'Mackris, Thom G.'; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve Igor: You're right, ruby and sapphire are members of the corundum family, which is aluminum oxide, Al2O3. They are relatively easy to synthesize. The hardness of minerals is measured by the Mohs' scale rather than the Rockwell test. The Mohs' scale ranges from 1 to 10 with 10 being the hardest, represented by diamond. Corundum is 9, still extremely hard. I estimate that brass and delrin would be about 3 or possibly 4 on the scale, which is considerably softer. Carbide is similar to corundum in hardness, and traditional bearing theory says that you don't want mating surfaces to be similar in hardness. If I used a jeweled pad I would probably stay with the ball bearing (~6) for that reason. A classic test of the relative Mohs' hardness is to see what scratches what (just like the jeweler does in a bad mystery movie). In my mind, a quartz crystal (7) will scratch a ball bearing, so I rate the ball bearing a 6. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Igor Kuznetsoff [SMTP:gorkuz@yahoo.com] > Sent: Tuesday, February 08, 2000 12:40 PM > To: Schei, Kenneth; 'Jon Lane [h]'; 'Mackris, Thom G.'; Anderson, Ivan; > Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; > Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; > Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; > Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, > Fred; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, > Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; > Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, > David; Welborne, Ron; Wright, Allen; Zettell, Steve > Subject: RE: Teres-Bearing & Platter > > Jon, Ken, > These are interesting comments. I too am > curious about where Carbide balls and jeweled thrust > plates can be obtained from and cost. The jeweling > is, if I understand correctly, a close relative of > Ruby by way of (both) being an aluminun oxide with > various trace elements. Aluminum oxide is, of course, > extremely hard, which is why it is used in making > sandpaper, among other things. My concern with using > carbide on aluminum oxide would be with how quietly > the two would interact. I had the good fortune to > spend some hours listening to and playing with the > Goldmund TT at Listen Up in Boulder back during the > '80's, when I lived in Vail. An interesting & > complicated machine, for that time. One of the things > > I was *not* impressed with was a quiet noise floor. > To be sure, I have no way of determining the cause for > this, I did not play with enough of that audio chain > to > to pin that down, only swapped the amps & some > interconnects around. Still, I remember this about > that rig well enough for it to have come to mind. > There is no doubt that there is likely to be an > audible difference between the Delrin and the > Carbide/Alumina combination, though which is superior, > and to whose tastes, would be a try it and hear. The > nice thing about our design is that these & others can > be tried interchangeably. Ken, do you have the > Rockwell (hardness) numbers available for these > materials, as well as Brass, for a curiousity > satisfying comparison? > > --- "Schei, Kenneth" wrote: > > Jon: > > > > Thanks for the valuable input - your points are well > > thought out and quite > > interesting. Since the delrin bearing is removable, > > we have the options to > > make modifications just as you plan to do. Where > > can you obtain a jeweled > > thrust plate and how much would one cost? I may > > want to experiment with one > > myself. One of my other interests is old Swiss > > watches, which of course use > > jewels (synthetic rubys) for bearings, but mainly > > for extended > > wear-resistance, rather than any audible reasons, > > although a fine Swiss > > watch sounds much smoother than a cheaper one. > > > > Ken > > > > Ken Schei, P.E. > > Project Engineer > > Antarctic Support Associates > > Email address: scheike@asa.org > > Phone: 303-643-0163 > > > > > -----Original Message----- > > > From: Jon Lane [h] [SMTP:jhlane@email.msn.com] > > > Sent: Monday, February 07, 2000 7:23 PM > > > To: Schei, Kenneth; 'Mackris, Thom G.'; Anderson, > > Ivan; Bailey, Tim; > > > Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, > > Peter; Brady, Chris; > > > Bronner, Gary; Carron, Don; Clark, Peter; Collier > > (w), Dave; Day (h), > > > Brian; Druley, Joe; Epstein (w), Jeremy; Gassman > > (h), Grant; Gesualdo, > > > Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; > > Humphrey, Fred; > > > Kuznetsoff, Igor; Mackris (h), Thom; Martin (w), > > Thomas; Martin(h), > > > Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, > > William; Munger (w), > > > George; Ono, Stewart; Pao, Sammy; Pickwoad (h), > > Bob; Primrose, Roscoe; > > > Sellek, Grant; Suess, David; Welborne, Ron; > > Wright, Allen; Zettell, Steve > > > Subject: Re: Teres-Bearing & Platter > > > > > > > There have been a lot of questions in the past > > regarding the > > > use of a Delrin > > > > bearing pad. Most of these questions seem to > > stem from the > > > conception that > > > > Delrin may be too soft for the intended purpose. > > Delrin is a > > > DuPont trade > > > > name for acetyl plastic. It is extremely tough > > and one of its > > > most > > > > recommended applications is for bearing > > components. In bearing > > > applications > > > > it will outwear nylon by a factor of 4. The two > > most important > > > > characteristics of Delrin for our use are its > > natural lubricity > > > and its > > > > surface hardness. Surface hardness is commonly > > measured by a > > > durometer > > > > test, which measures the indentation by a > > calibrated probe. > > > Delrin actually > > > > has a greater surface hardness than brass, which > > is another > > > common bearing > > > > material. In our application, Delrin would be > > harder and more > > > slippery than > > > > brass. If we wanted to discard Delrin as a > > bearing pad, it > > > would be more > > > > likely because it was too hard, not too soft. I > > believe Delrin > > > is the ideal > > > > material for our bearing pad. > > > > > > > > Ken > > > > > > Good post, Ken, you've summed up the advantages of > > Delrin > > > perfectly. In fact, this material is specifically > > intended as a > > > bearing surface... > > > > > > I think the only point against Delrin would be > > argued for another > > > reason entirely. That is, not that Delrin is a > > poor bearing with > > > finite wear capability, but that it could be > > improved on in the > > > areas of noise and the transmission of such. > > > > > > Many 'tables have specifically been designed with > > means of > > > mechanical coupling, of which perhaps the Goldmund > > was, when it > > > appeared, the most notable. These designs relied > > on extremely > > > hard bearings to complete the mechanical ground > > between > > > components. The thinking, apparently, was that > > micro-information > > > could only be retrieved by extreme coupling and > > the mechanical > > > grounding of vibration. Given the successes of > > everything from > > > the Linn thru SOTA even to today's better sounding > > designs, this > > > concept has been proven time and again. > > > > > > Personally, I am going to experiment with a > > carbide ball and > > > jeweled thrust plate right off in my Teres. There > > is no doubt in > > > my mind but that the differences between hard and > > relatively soft > > > interfaces at this critical location will indeed > > be audible, even > > > if the subjective preferences will probably vary > > all over the > > > map. It should be an interesting experiment. > > > > > > While I did once build a Delrin-bearing 'table, > > and it was > > > reasonably good, I also fear for the long-term > > variability as the > > > Delrin deforms to the extreme pressure presented > > by a heavy > > > platter through a point contact area. As the > > Delrin "cups" > > > imperceptibly (just as brass would over time, to > > use your > > > example) the mechanical sinking will also vary and > > the > > > possibility for minute amounts of frictional noise > > to creep into > > > the system may rise. Again, the sonic result is > > hard to predict > > > but is still likely to be audible as the pieces > > wear in. > > > > > > One last comment: The Oracle and, I think, the > > Linn both use > > > hard thrust surfaces but rather cheap sleeve > > bearings. The > > > Oracle used a manufactured sleeve of bearing > > plastic in a metal > > > shell in two places and I think the Linn may also. > > In this > > > regard, I expect the Teres to be far superior. > > Its likely that > > > the machined female part of the Teres will be to a > > far tighter > > > tolerance. > > > > > > Jon Lane > > > > > > > > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com Subject: RE: Teres-Bearing & Platter Date: Tue, 8 Feb 2000 16:28:51 -0700 From: Mackris, Thom G., Mackris, Thom G. To: 'Schei, Kenneth'; 'Igor Kuznetsoff'; 'Jon Lane [h]'; Mackris, Thom G.; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve An argument for a replacable delrin pad ... no? The delrin wears after 5 or 10 or 20 years and it gets replaced, not the spindle. -----Original Message----- From: Schei, Kenneth [mailto:SCHEIKE@asa.org] Sent: Tuesday, February 08, 2000 2:44 PM T Subject: RE: Teres-Bearing & Platter Igor: You're right, ruby and sapphire are members of the corundum family, which is aluminum oxide, Al2O3. They are relatively easy to synthesize. The hardness of minerals is measured by the Mohs' scale rather than the Rockwell test. The Mohs' scale ranges from 1 to 10 with 10 being the hardest, represented by diamond. Corundum is 9, still extremely hard. I estimate that brass and delrin would be about 3 or possibly 4 on the scale, which is considerably softer. Carbide is similar to corundum in hardness, and traditional bearing theory says that you don't want mating surfaces to be similar in hardness. If I used a jeweled pad I would probably stay with the ball bearing (~6) for that reason. A classic test of the relative Mohs' hardness is to see what scratches what (just like the jeweler does in a bad mystery movie). In my mind, a quartz crystal (7) will scratch a ball bearing, so I rate the ball bearing a 6. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Igor Kuznetsoff [SMTP:gorkuz@yahoo.com] > Sent: Tuesday, February 08, 2000 12:40 PM > To: Schei, Kenneth; 'Jon Lane [h]'; 'Mackris, Thom G.'; Anderson, Ivan; > Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; > Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; > Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; > Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, > Fred; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, > Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; > Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, > David; Welborne, Ron; Wright, Allen; Zettell, Steve > Subject: RE: Teres-Bearing & Platter > > Jon, Ken, > These are interesting comments. I too am > curious about where Carbide balls and jeweled thrust > plates can be obtained from and cost. The jeweling > is, if I understand correctly, a close relative of > Ruby by way of (both) being an aluminun oxide with > various trace elements. Aluminum oxide is, of course, > extremely hard, which is why it is used in making > sandpaper, among other things. My concern with using > carbide on aluminum oxide would be with how quietly > the two would interact. I had the good fortune to > spend some hours listening to and playing with the > Goldmund TT at Listen Up in Boulder back during the > '80's, when I lived in Vail. An interesting & > complicated machine, for that time. One of the things > > I was *not* impressed with was a quiet noise floor. > To be sure, I have no way of determining the cause for > this, I did not play with enough of that audio chain > to > to pin that down, only swapped the amps & some > interconnects around. Still, I remember this about > that rig well enough for it to have come to mind. > There is no doubt that there is likely to be an > audible difference between the Delrin and the > Carbide/Alumina combination, though which is superior, > and to whose tastes, would be a try it and hear. The > nice thing about our design is that these & others can > be tried interchangeably. Ken, do you have the > Rockwell (hardness) numbers available for these > materials, as well as Brass, for a curiousity > satisfying comparison? > > --- "Schei, Kenneth" wrote: > > Jon: > > > > Thanks for the valuable input - your points are well > > thought out and quite > > interesting. Since the delrin bearing is removable, > > we have the options to > > make modifications just as you plan to do. Where > > can you obtain a jeweled > > thrust plate and how much would one cost? I may > > want to experiment with one > > myself. One of my other interests is old Swiss > > watches, which of course use > > jewels (synthetic rubys) for bearings, but mainly > > for extended > > wear-resistance, rather than any audible reasons, > > although a fine Swiss > > watch sounds much smoother than a cheaper one. > > > > Ken > > > > Ken Schei, P.E. > > Project Engineer > > Antarctic Support Associates > > Email address: scheike@asa.org > > Phone: 303-643-0163 > > > > > -----Original Message----- > > > From: Jon Lane [h] [SMTP:jhlane@email.msn.com] > > > Sent: Monday, February 07, 2000 7:23 PM > > > To: Schei, Kenneth; 'Mackris, Thom G.'; Anderson, > > Ivan; Bailey, Tim; > > > Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, > > Peter; Brady, Chris; > > > Bronner, Gary; Carron, Don; Clark, Peter; Collier > > (w), Dave; Day (h), > > > Brian; Druley, Joe; Epstein (w), Jeremy; Gassman > > (h), Grant; Gesualdo, > > > Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; > > Humphrey, Fred; > > > Kuznetsoff, Igor; Mackris (h), Thom; Martin (w), > > Thomas; Martin(h), > > > Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, > > William; Munger (w), > > > George; Ono, Stewart; Pao, Sammy; Pickwoad (h), > > Bob; Primrose, Roscoe; > > > Sellek, Grant; Suess, David; Welborne, Ron; > > Wright, Allen; Zettell, Steve > > > Subject: Re: Teres-Bearing & Platter > > > > > > > There have been a lot of questions in the past > > regarding the > > > use of a Delrin > > > > bearing pad. Most of these questions seem to > > stem from the > > > conception that > > > > Delrin may be too soft for the intended purpose. > > Delrin is a > > > DuPont trade > > > > name for acetyl plastic. It is extremely tough > > and one of its > > > most > > > > recommended applications is for bearing > > components. In bearing > > > applications > > > > it will outwear nylon by a factor of 4. The two > > most important > > > > characteristics of Delrin for our use are its > > natural lubricity > > > and its > > > > surface hardness. Surface hardness is commonly > > measured by a > > > durometer > > > > test, which measures the indentation by a > > calibrated probe. > > > Delrin actually > > > > has a greater surface hardness than brass, which > > is another > > > common bearing > > > > material. In our application, Delrin would be > > harder and more > > > slippery than > > > > brass. If we wanted to discard Delrin as a > > bearing pad, it > > > would be more > > > > likely because it was too hard, not too soft. I > > believe Delrin > > > is the ideal > > > > material for our bearing pad. > > > > > > > > Ken > > > > > > Good post, Ken, you've summed up the advantages of > > Delrin > > > perfectly. In fact, this material is specifically > > intended as a > > > bearing surface... > > > > > > I think the only point against Delrin would be > > argued for another > > > reason entirely. That is, not that Delrin is a > > poor bearing with > > > finite wear capability, but that it could be > > improved on in the > > > areas of noise and the transmission of such. > > > > > > Many 'tables have specifically been designed with > > means of > > > mechanical coupling, of which perhaps the Goldmund > > was, when it > > > appeared, the most notable. These designs relied > > on extremely > > > hard bearings to complete the mechanical ground > > between > > > components. The thinking, apparently, was that > > micro-information > > > could only be retrieved by extreme coupling and > > the mechanical > > > grounding of vibration. Given the successes of > > everything from > > > the Linn thru SOTA even to today's better sounding > > designs, this > > > concept has been proven time and again. > > > > > > Personally, I am going to experiment with a > > carbide ball and > > > jeweled thrust plate right off in my Teres. There > > is no doubt in > > > my mind but that the differences between hard and > > relatively soft > > > interfaces at this critical location will indeed > > be audible, even > > > if the subjective preferences will probably vary > > all over the > > > map. It should be an interesting experiment. > > > > > > While I did once build a Delrin-bearing 'table, > > and it was > > > reasonably good, I also fear for the long-term > > variability as the > > > Delrin deforms to the extreme pressure presented > > by a heavy > > > platter through a point contact area. As the > > Delrin "cups" > > > imperceptibly (just as brass would over time, to > > use your > > > example) the mechanical sinking will also vary and > > the > > > possibility for minute amounts of frictional noise > > to creep into > > > the system may rise. Again, the sonic result is > > hard to predict > > > but is still likely to be audible as the pieces > > wear in. > > > > > > One last comment: The Oracle and, I think, the > > Linn both use > > > hard thrust surfaces but rather cheap sleeve > > bearings. The > > > Oracle used a manufactured sleeve of bearing > > plastic in a metal > > > shell in two places and I think the Linn may also. > > In this > > > regard, I expect the Teres to be far superior. > > Its likely that > > > the machined female part of the Teres will be to a > > far tighter > > > tolerance. > > > > > > Jon Lane > > > > > > > > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com Subject: Teres Turntable - Lubrication Question Date: Tue, 8 Feb 2000 19:05:21 -0700 From: Mackris, Thom G., Mackris, Thom G. To: 'Mackris (h), Thom' > -----Original Message----- > From: Mackris, Thom G. > Sent: Tuesday, February 08, 2000 5:57 PM > To: 'nigel@home.com' > Subject: Teres Turntable - Lubrication Question > > Hi Nigel, > > Bob had referred me to you with the disclaimer that bearing design and > lubrication might not be your area of specialty. I thought that you'd > find our > project interesting nevertheless, and hence I'm writing this in the event > that > you might have some comments. > > A group of us (it started with a half dozen, and now it's up to three > dozen!) > are in the process of assaulting the state of the art in a turntable. > Check > out my friend Chris Brady's web page (click on the link - "Teres DIY > Turntable") ==> http://reality.sgi.com/cbrady_denver/audio/ > > I currently own a Merrill like Bob's, and originally this project was just > a matter > of curiosity. I have come to the opinion that we might be onto something > very > special here. > > This merry band of pranksters started out by considering building a kit > turntable designed by Thomas Scheu of Germany. It has been reported by > many > to be better than the $7500.00 Platine Verdier. Pretty soon we realized > that we had the talent on tap to design one ourselves. > > A recent post to the Joe List (Sound Practices list server) resulted in > the > number of 'tables committed to purchase approaching two dozen!! We have > an > electrical engineer who has designed a micro code controlled motor > controller for his Thomas Scheu turntable. He has volunteered to help us > adapt the design to our 'table. This controller promises to leave the > Linn > Lingo, Naim Armegeddon and VPI controllers in the dust from both a > performance standpoint as well as one of convenience. It will even have > motion sensing - if you give the platter a nudge, it will sense that you > want to start it up !!! All for a cost of ~ $100.00 !! > > Anyhow, we've been going back and forth about lubrication for the bearing. > My friend Chris's brother is a CNC machinist who has specialized in making > computer disk drives ... the breadth of talent on this project has me > dizzy > !! The bearing is going to be a male, stainless steel spindle with a ball > bearing > thrust surface. The female will be machined brass, with a delrin thrust > plate. > There will be a well in the central portion of the bearing to reduce > bearing > surface contact (lower noise) as well as to effect viscuous damping. > The drawings are on the web page. The male surface of the bearing will be > > polished, and the tolerances are being specified as the tightest possible > ... > in other words, we will most likely be using a light oil. > > Some have expressed concern about delrin's suitability to the task, but > our > machinist agrees with others in the group (including a structural engineer > and a former Formula 3 race car mechanic) that this is an ideal material > for > a thrust plate - extramely tough, natural lubricity, and most certainly > stronger than teflon (with less deformability) and quieter than brass or > scintered bronze. > > The question of toughness, specifying the correct lubricant as well as the > thrust surface interface arose. Note the quoted text immediately > following. The poster is advocating using a large contact area thrust > plate interface > which will float the spindle on a cushion of oil. Our feelings are that > the ball > bearing/delrin interface is just fine, and that depending on a lubricant > for the > thrust plate interface might compromise the lubricant we might otherwise > specify. It seems as if many fine turntables (including the Thomas Scheu) > have such tight bearing tolerances that they specify a very light oil, > contrary > for example to Linn & Merrill. > > We are quite confident of the design and in the absence of any > extroadinary information, will go with the Delrin thrust plate / ball > bearing > spindle arrangement. Does anything seem grossly out of wack to you? > Note, that we are talking about a 15 lb. acrylic platter. > > > Regards, > Thom > > ---------------------------------------- > Quoted text follows ...... > > Which brings me back to point one. Would a very large radius at > the end of the spindle actually support even Teres' thrust load > on a similar oil film? I don't know the math but presumably at > some larger contact area (maybe as would be formed if the entire > end of a large diameter shaft were contacting our Delrin thrust > pad) the oil will actually float the end load imposed by the > platter weight. Seems to me that an analysis of oil shear > strength, rotational speed, and bearing contact size would be the > only variables needing to calculate this problem. Any lubricant > engineers in the team? > > One of my reasons for asking for a removable end to the sleeve is > because I actually want to try metal-to-metal with only oil in > between. I think it may work if the end of the shaft is nearly > flat. Play around with a precision shaft in a precision sleeve > with your fingers sometime. With only fine machine oil, its > virtually impossible to make the two touch. Oil gives amazing > protection. The same is even true for air bearings under enough > pressure. > > > End quoted text > ---------------------------------------- > Subject: Re: Teres-Bearing & Platter Date: Tue, 8 Feb 2000 19:34:46 -0700 From: Jon Lane [h], Jon Lane [h] To: Schei, Kenneth; 'Mackris, Thom G.'; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve > Where can you obtain a jeweled > thrust plate and how much would one cost? I may want to experiment with one > myself. One of my other interests is old Swiss watches, which of course use > jewels (synthetic rubys) for bearings, but mainly for extended > wear-resistance, rather than any audible reasons, although a fine Swiss > watch sounds much smoother than a cheaper one. When the time comes, I'm just going to start searching. I do recall the name, Bird Precision with regard to jeweled bearing parts. Maybe a start there... More importantly, as has been already mentioned by Thom (thanks, sir, for asking this necessary question) is the need to have a removable Delrin puck. And conversely, an option to receive the spindle with the ball NOT - repeat NOT - permanently installed. Is this a possibility? Or is the ball already a carbide-type thingie ready for the rigors of life against a sapphire or ceramic pad...? Jon Lane Subject: Re: Teres-Bearing & Platter Date: Tue, 8 Feb 2000 22:55:12 -0700 From: Stewart Ono, Stewart Ono To: Jon Lane [h]; Schei, Kenneth; 'Mackris, Thom G.'; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, David; Welborne, Ron; Wright, Allen; Zettell, Steve Nothing serious here, as I believe the major aspects of the TT design are being very nicely handled. The Delrin thrust pad, with its high durometer rating seems more than acceptable. However, in an oil bath would the pad itself be prone to spinning? That would raise the noise floor a hair, I suppose. Of course we could easily make the Delrin pad to be a slight friction fit to counter the tendency. Any thoughts by the others on this? For ease of removal, I imagine we could scallop the edge so as to be able to slip a dental tool of some sort to pry the pad out. Bryce wouldn't even have to do that as it should be easy to do in the field. regards, Stu Subject: RE: Teres-Bearing & Platter Date: Wed, 9 Feb 2000 08:40:14 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'Thom Mackris / Joan Panzella'; Jon Lane [h]; 'Mackris, Thom G.'; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, David; Welborne, Ron; Zettell, Steve That's my understanding also. IMHO, the stainless ball bearing is an ideal solution. Ball bearings are readily available at easonable prices, high precision, and their hardness is a nice match to either brass or Delrin, which are softer, or to a jeweled pad, which is harder. I still believe that our initial design should adhere to bearing design philosophy which dictates that the mating surfaces be of different hardnesses. We can also experiment later with matching very hard surfaces if we desire. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Thom Mackris / Joan Panzella [SMTP:tmackris@earthlink.net] > Sent: Tuesday, February 08, 2000 8:07 PM > To: Jon Lane [h]; Schei, Kenneth; 'Mackris, Thom G.'; Anderson, Ivan; > Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; > Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; > Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; > Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, > Fred; Kuznetsoff, Igor; Martin (w), Thomas; Martin(h), Thomas; Maughan, > Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; > Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, > David; Welborne, Ron; Wright, Allen; Zettell, Steve > Subject: Re: Teres-Bearing & Platter > > My understanding is that it's stainless. > > Action item ? I smell questions for Bryce (poor guy). > > Thom > > ----- Original Message ----- > From: Jon Lane [h] > Sent: Tuesday, February 08, 2000 6:26 PM > Subject: Re: Teres-Bearing & Platter > > [Ken's question about sourcing jewelled bearings snipped] > > When the time comes, I'm just going to start searching. I do > recall the name, Bird Precision with regard to jeweled bearing > parts. Maybe a start there... > > More importantly, as has been already mentioned by Thom (thanks, > sir, for asking this necessary question) is the need to have a > removable Delrin puck. And conversely, an option to receive the > spindle with the ball NOT - repeat NOT - permanently installed. > Is this a possibility? Or is the ball already a carbide-type > thingie ready for the rigors of life against a sapphire or > ceramic pad...? > > Jon Lane > > > > Subject: RE: Teres-Bearing & Platter Date: Wed, 9 Feb 2000 09:39:45 -0700 From: Mackris, Thom G., Mackris, Thom G. To: Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Schei (h), Ken; Schei (w), Ken; Sellek, Grant; Suess, David; Welborne, Ron; Zettell, Steve So ... the stainless ball is field replacable (as apposed to a press fit)? Let's confirm this point if we can't get carbide. Reminder - let's try to keep poor Allen Wright off our distributions, per his request. Thom -----Original Message----- From: Schei, Kenneth [mailto:SCHEIKE@asa.org] Sent: Wednesday, February 09, 2000 7:43 AM Subject: RE: Teres-Bearing & Platter That's my understanding also. IMHO, the stainless ball bearing is an ideal solution. Ball bearings are readily available at easonable prices, high precision, and their hardness is a nice match to either brass or Delrin, which are softer, or to a jeweled pad, which is harder. I still believe that our initial design should adhere to bearing design philosophy which dictates that the mating surfaces be of different hardnesses. We can also experiment later with matching very hard surfaces if we desire. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 Subject: Re: Teres-Bearing & Platter Date: Wed, 9 Feb 2000 13:31:03 -0700 From: Chris Brady, Chris Brady To: Mackris, Thom G. CC: Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Schei (h), Ken; Schei (w), Ken; Sellek, Grant; Suess, David; Welborne, Ron; Zettell, Steve; wtmoy@pica.army.mil I have some new information and clarification regarding the bearing and platter. But before I get into the details I am announcing that this is my last e-mail to this e-mail list. It is just too difficult to keep track of new members. So if you want to keep getting updates please sign up with the Teres list server. Thanks Roscoe for setting this up for us. 1) Removal of the thrust plate - The thrust plate will not have a friction fit and will just drop in place. We don't need to worry at all about it moving around since there will be a large surface area contacting the bottom of the bearing well compared to the very small contact area of the ball bearing. The weight of the platter and spindle will hold it securely in place. 2) Removal of the ball bearing - I talked to Bryce and he is planning to make the ball bearing removable. He does not want to press the bearing into the shaft because it could interfere with the close tolerances on the bearing surfaces. The plan is for a close tolerance fit and use of a small amount of adhesive to keep the bearing in the shaft. 3) Ball Bearing - The plan is to use a hardened steel ball bearing and not carbide or ceramic. If the majority of the group would like to upgrade to a harder material we can do so. I would prefer staying with what we have and then individually experimenting with other materials as we see fit. 4) Lamination of the platter - Bryce will have the acrylic cut by his supplier and he will do the lamination using a vacuum bag. He is expecting that with this technique there will be no bubbles. If there are any bubbles they will be very small and few. With the vacuum bag the clamping pressure will be about 1800lbs so we need not be concerned in any way about the structural integrity of the joint. Bryce inquired about 3" material and the supplier said "You don't want to do that, the price is horrendous". The bottom line; we expect flawless cosmetics but can't guarantee it. 5) Shipping - There have been concerns expressed about shipping via UPS. However, Bryce has a setup that saves him time, money and headaches when he uses UPS. So his stated policy is that the shipping will be UPS unless it is to someplace outside of the US. For those outside of the US there will be an extra $10 shipping charge. Bryce is not being unreasonable. Going to the post office takes time and time is money. That's it for now. Chris Subject: [teres] Re: Teres-Bearing & Platter Date: Wed, 9 Feb 2000 13:47:47 -0700 From: Chris Brady, Chris Brady To: teres@aiko.com For a very hard thrust plate we could try using worn out carbide tooling inserts. They are triangular and about 1/8" thick. We may have to grind off the corners to make them fit. I think that carbide is harder than saphire or ruby and the price would be right. Chris "Schei, Kenneth" wrote: > > That's my understanding also. IMHO, the stainless ball bearing is an ideal > solution. Ball bearings are readily available at easonable prices, high > precision, and their hardness is a nice match to either brass or Delrin, > which are softer, or to a jeweled pad, which is harder. I still believe > that our initial design should adhere to bearing design philosophy which > dictates that the mating surfaces be of different hardnesses. We can also > experiment later with matching very hard surfaces if we desire. > > Ken > > Ken Schei, P.E. > Project Engineer > Antarctic Support Associates > Email address: scheike@asa.org > Phone: 303-643-0163 > > > -----Original Message----- > > From: Thom Mackris / Joan Panzella [SMTP:tmackris@earthlink.net] > > Sent: Tuesday, February 08, 2000 8:07 PM > > To: Jon Lane [h]; Schei, Kenneth; 'Mackris, Thom G.'; Anderson, Ivan; > > Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; > > Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; > > Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; > > Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, > > Fred; Kuznetsoff, Igor; Martin (w), Thomas; Martin(h), Thomas; Maughan, > > Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; > > Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, > > David; Welborne, Ron; Wright, Allen; Zettell, Steve > > Subject: Re: Teres-Bearing & Platter > > > > My understanding is that it's stainless. > > > > Action item ? I smell questions for Bryce (poor guy). > > > > Thom > > > > ----- Original Message ----- > > From: Jon Lane [h] > > Sent: Tuesday, February 08, 2000 6:26 PM > > Subject: Re: Teres-Bearing & Platter > > > > [Ken's question about sourcing jewelled bearings snipped] > > > > When the time comes, I'm just going to start searching. I do > > recall the name, Bird Precision with regard to jeweled bearing > > parts. Maybe a start there... > > > > More importantly, as has been already mentioned by Thom (thanks, > > sir, for asking this necessary question) is the need to have a > > removable Delrin puck. And conversely, an option to receive the > > spindle with the ball NOT - repeat NOT - permanently installed. > > Is this a possibility? Or is the ball already a carbide-type > > thingie ready for the rigors of life against a sapphire or > > ceramic pad...? > > > > Jon Lane > > > > > > > > Subject: RE: Teres-Bearing & Platter Date: Wed, 9 Feb 2000 14:34:40 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: Schei, Kenneth; 'Thom Mackris / Joan Panzella'; Jon Lane [h]; 'Mackris, Thom G.'; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Sellek, Grant; Suess, David; Welborne, Ron; Zettell, Steve I agree with Ken about the surface matches. And stainless steel sounds practical, unless, I suppose, we can find carbide. We should keep in mind that if the ball is not pressed into the spindle, we will have to fish it out from the bearing to remove it without turning everything upside down. This is not a big problem as that can be done with a drinking straw & a little suction. More important is another consideration. We would not want it wandering around inside of its (spindle) recess. This would not be conducive to stability or quiet. It would therefore *require* a snug / zero clearance fit (if not quite a press fit), with some provision for removal. Obviously, it would be simpler to just press it in & forget it, although replaceability is a plus. Alternately, the (top) contact surface within the bearing recess in the spindle would need a large radius concavity, as discussed some time ago, to effect auto centering in order to promote stability. This would be an inferior choice, IMHO. Igor --- "Schei, Kenneth" wrote: > That's my understanding also. IMHO, the stainless > ball bearing is an ideal > solution. Ball bearings are readily available at > easonable prices, high > precision, and their hardness is a nice match to > either brass or Delrin, > which are softer, or to a jeweled pad, which is > harder. I still believe > that our initial design should adhere to bearing > design philosophy which > dictates that the mating surfaces be of different > hardnesses. We can also > experiment later with matching very hard surfaces if > we desire. > > Ken > > Ken Schei, P.E. > Project Engineer > Antarctic Support Associates > Email address: scheike@asa.org > Phone: 303-643-0163 > > > -----Original Message----- > > From: Thom Mackris / Joan Panzella > [SMTP:tmackris@earthlink.net] > > Sent: Tuesday, February 08, 2000 8:07 PM > > To: Jon Lane [h]; Schei, Kenneth; 'Mackris, Thom > G.'; Anderson, Ivan; > > Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, > Tony; Boser, Peter; > > Brady, Chris; Bronner, Gary; Carron, Don; Clark, > Peter; Collier (w), Dave; > > Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; > Gassman (h), Grant; > > Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, > Manfred; Humphrey, > > Fred; Kuznetsoff, Igor; Martin (w), Thomas; > Martin(h), Thomas; Maughan, > > Gordon; Mitaru, Alex; Mollard, William; Munger > (w), George; Ono, Stewart; > > Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; > Sellek, Grant; Suess, > > David; Welborne, Ron; Wright, Allen; Zettell, > Steve > > Subject: Re: Teres-Bearing & Platter > > > > My understanding is that it's stainless. > > > > Action item ? I smell questions for Bryce (poor > guy). > > > > Thom > > > > ----- Original Message ----- > > From: Jon Lane [h] > > Sent: Tuesday, February 08, 2000 6:26 PM > > Subject: Re: Teres-Bearing & Platter > > > > [Ken's question about sourcing jewelled bearings > snipped] > > > > When the time comes, I'm just going to start > searching. I do > > recall the name, Bird Precision with regard to > jeweled bearing > > parts. Maybe a start there... > > > > More importantly, as has been already mentioned by > Thom (thanks, > > sir, for asking this necessary question) is the > need to have a > > removable Delrin puck. And conversely, an option > to receive the > > spindle with the ball NOT - repeat NOT - > permanently installed. > > Is this a possibility? Or is the ball already a > carbide-type > > thingie ready for the rigors of life against a > sapphire or > > ceramic pad...? > > > > Jon Lane > > > > > > > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: TERES ACTION ITEMS / PURCHASE / SCHEDULE Date: Wed, 9 Feb 2000 14:49:07 -0700 From: Mackris, Thom G., Mackris, Thom G. To: 'Teres_List'; Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Schei (h), Ken; Schei (w), Ken; Sellek, Grant; Suess, David; Welborne, Ron; Zettell, Steve All, This is great work, yet again. You're our hero Chris! I renamed the subject & placed it in CAPS to grab everyone's attention. Note: I sent this to both majordomo *and* to the mailing list. I think we should give the folks a couple of days to switch to majordomo - after we solidify the orders on Friday would be a good time to do this. We'd hate to miss someone due to a personal problem. As an extra failsafe, I will be sending all of these high priority messages (all CAPS in the subject) to both majordomo and the list - through the weekend. After that, it's majordomo or nothing. Tonight, I will be speaking with Chris, and we will re-state and re-publish exactly what's going to be coming from Bryce. I don't think there are any open items, especially with both thrust plate and ball bearing being removable and easily field replacable. With respect to bubbles in the laminations and everyone's risk tolerance for it, here's my take on the matter: Assume that you're hyper-finnicky and that a few bubbles end up in your platter. You still have (from a mechanical perspective) a world class platter and bearing at a price that Scheu charges for a bearing alone, and you can at your leisure experiment with other platters from a local machinist ... multiple materials are subsequently possible (i.e. laminations of different materials), and you have an acrylic platter as a baseline of comparison. Cheers, Thom -----Original Message----- From: Chris Brady [mailto:cbrady@sgi.com] Sent: Wednesday, February 09, 2000 12:30 PM Subject: Re: Teres-Bearing & Platter I have some new information and clarification regarding the bearing and platter. But before I get into the details I am announcing that this is my last e-mail to this e-mail list. It is just too difficult to keep track of new members. So if you want to keep getting updates please sign up with the Teres list server. Thanks Roscoe for setting this up for us. 1) Removal of the thrust plate - The thrust plate will not have a friction fit and will just drop in place. We don't need to worry at all about it moving around since there will be a large surface area contacting the bottom of the bearing well compared to the very small contact area of the ball bearing. The weight of the platter and spindle will hold it securely in place. 2) Removal of the ball bearing - I talked to Bryce and he is planning to make the ball bearing removable. He does not want to press the bearing into the shaft because it could interfere with the close tolerances on the bearing surfaces. The plan is for a close tolerance fit and use of a small amount of adhesive to keep the bearing in the shaft. 3) Ball Bearing - The plan is to use a hardened steel ball bearing and not carbide or ceramic. If the majority of the group would like to upgrade to a harder material we can do so. I would prefer staying with what we have and then individually experimenting with other materials as we see fit. 4) Lamination of the platter - Bryce will have the acrylic cut by his supplier and he will do the lamination using a vacuum bag. He is expecting that with this technique there will be no bubbles. If there are any bubbles they will be very small and few. With the vacuum bag the clamping pressure will be about 1800lbs so we need not be concerned in any way about the structural integrity of the joint. Bryce inquired about 3" material and the supplier said "You don't want to do that, the price is horrendous". The bottom line; we expect flawless cosmetics but can't guarantee it. 5) Shipping - There have been concerns expressed about shipping via UPS. However, Bryce has a setup that saves him time, money and headaches when he uses UPS. So his stated policy is that the shipping will be UPS unless it is to someplace outside of the US. For those outside of the US there will be an extra $10 shipping charge. Bryce is not being unreasonable. Going to the post office takes time and time is money. That's it for now. Chris Subject: Re: Teres-Bearing & Platter Date: Wed, 9 Feb 2000 14:58:38 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: Chris Brady; Mackris, Thom G. CC: Anderson, Ivan; Bailey, Tim; Beck, Chris; Boehler, Brian; Bombera, Tony; Boser, Peter; Brady, Chris; Bronner, Gary; Carron, Don; Clark, Peter; Collier (w), Dave; Day (h), Brian; Druley, Joe; Epstein (w), Jeremy; Gassman (h), Grant; Gesualdo, Terry; Gon, Martin; Goudge, Stan; Huber, Manfred; Humphrey, Fred; Kuznetsoff, Igor; Lane, Jon; Mackris (h), Thom; Martin (w), Thomas; Martin(h), Thomas; Maughan, Gordon; Mitaru, Alex; Mollard, William; Munger (w), George; Ono, Stewart; Pao, Sammy; Pickwoad (h), Bob; Primrose, Roscoe; Schei (h), Ken; Schei (w), Ken; Sellek, Grant; Suess, David; Welborne, Ron; Zettell, Steve; wtmoy@pica.army.mil One through five all in line with reality. Could those that wish to try other balls remove theirs, without risk of distorting the critical surfaces? I have no such plans, but the question has come up. Igor --- Chris Brady wrote: > I have some new information and clarification > regarding > the bearing and platter. > > But before I get into the details I am announcing > that > this is my last e-mail to this e-mail list. It is > just > too difficult to keep track of new members. So if > you > want to keep getting updates please sign up with the > Teres list server. Thanks Roscoe for setting this > up > for us. > > 1) Removal of the thrust plate - The thrust plate > will not > have a friction fit and will just drop in place. > We > don't need to worry at all about it moving around > since there will be a large surface area > contacting > the bottom of the bearing well compared to the > very > small contact area of the ball bearing. The > weight of > the platter and spindle will hold it securely in > place. > > 2) Removal of the ball bearing - I talked to Bryce > and he > is planning to make the ball bearing removable. > He does > not want to press the bearing into the shaft > because it > could interfere with the close tolerances on the > bearing > surfaces. The plan is for a close tolerance fit > and use > of a small amount of adhesive to keep the bearing > in the > shaft. > > 3) Ball Bearing - The plan is to use a hardened > steel ball > bearing and not carbide or ceramic. If the > majority of > the group would like to upgrade to a harder > material we > can do so. I would prefer staying with what we > have and > then individually experimenting with other > materials as > we see fit. > > 4) Lamination of the platter - Bryce will have the > acrylic > cut by his supplier and he will do the lamination > using a > vacuum bag. He is expecting that with this > technique > there will be no bubbles. If there are any > bubbles they > will be very small and few. With the vacuum bag > the > clamping pressure will be about 1800lbs so we > need not be > concerned in any way about the structural > integrity of the > joint. Bryce inquired about 3" material and the > supplier > said "You don't want to do that, the price is > horrendous". > The bottom line; we expect flawless cosmetics but > can't > guarantee it. > > 5) Shipping - There have been concerns expressed > about > shipping via UPS. However, Bryce has a setup > that saves > him time, money and headaches when he uses UPS. > So his > stated policy is that the shipping will be UPS > unless it is > to someplace outside of the US. For those > outside of the > US there will be an extra $10 shipping charge. > Bryce is > not being unreasonable. Going to the post office > takes time > and time is money. > > That's it for now. > > Chris > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: Teres-Bearing & Platter Date: Thu, 10 Feb 2000 10:16:27 -0700 From: Mackris, Thom G., Mackris, Thom G. To: 'Mackris (h), Thom' -----Original Message----- From: Steve Zettel [mailto:zettel@libby.org] Sent: Wednesday, February 09, 2000 9:30 PM To: Mackris, Thom G. Subject: Re: Teres-Bearing & Platter I agree that it is not a big deal to have it, and at the price increase to include a threaded hole, I would prefer to do it myself. My initial suggestion for including it was "wild assed idea" and it still falls in that catagory, or "gilding the lily". Certainly not necessary. If we clearly state what is included, then no one has any beef. I appreciate you, Chris and Ken keeping this on track with all the new folks. I would have taken a more pro-active role, but frankly, I have been overwhelmed with my Navy Reserve commitments while on active duty, and have barely had time to read my e-mail. Several comments about what has developed: My strongest recommendation that we pursue the elegant motor control circuitry proposed by Manfred Huber. Frankly, I doubt I could do any better, even if I devoted full time to it. His design is developed and proven, and we would be foolish not to take full advantage. Especially with Ron W. volunteering to get the boards done for such a reasonable price! About the boards, Ron quoted two prices, one slightly higher for having the board silk screened with component locations, etc. MOST HIGHLY recommended! Worth ten times the price in avoidance of problems, mis-wiring, etc. Manfred's comments about the motor are equally on the mark and consistant with the article about motor selection: avoid graphite brushes and ball bearings, both of which the Faulhauber has, as does the Pittman (brushes, at least). If we can get the specified Maxon for $50-60 per in a group buy, we should do it. Once we decide on the motor to go with the controller, then we can finalize the appropriate pulley diameter and style (narrow with flanges to fit a rubber band or round rubber belt, tall with one flange for magnetic tape or flat belts, etc). The can be purchased ready made for a nominal price. For folks not wanting to do the sophisticated motor control/power supply, we might be able to publish a detailed "how-to" article to get them in the right direction with easily available, generic parts (train power supply, or black box power supply and some suggestions for control etc. That's about it for now, I'll be back home sometime this coming Saturday, though I have to work Sunday. But things should be getting back to the normal chaos next week. Best regards, Steve Subject: Re: [teres] Re: My two cents after reading the attached digests Date: Sat, 12 Feb 2000 20:51:09 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: Stewart Ono; Micheal Larosa; teres@aiko.com Hi Michael, I think I addressed all but one item from your earlier e-mail. Note that I'm copying you and Stu Ono in addition to the list, as I believe that both of you have still not been successful in subscribing. Direct any questions or problems you might have to Roscoe at his "administrator's" address: owner-teres@aiko.com The only unanswered question has to do with the pulleys. The motor pulley will be addressed as part of the motor design, and it is highly probable that Bryce will be machining them. The original thinking was to make them of acrylic in order to maintain the same thermal expansion (relative speed accuracy) rate as the platter. With Manfred's design however, this may no longer be an issue. We will certainly kick this design around in the coming weeks. The whole issue of whether to incorporate idler pulley(s) into the design is also open at the moment, and will certainly play a part in the motor and subchassis dialogs. I think folks will split into a two camps: (a) one group favoring idlers and (b) the KISS group which won't. Fortunately, this part of the project is totally flexible. My concern about doing idler pulleys is that I think they must be done impeccably or not at all. I may just wait and stand on the shoulders of someone else's ambitious efforts before tackling it myself. It seems as if the safe bet is to machine the pulleys for later use even if one chooses to not explore this approach initially. Sourcing bearings for the pulleys will certainly be a challenge. Johannes Chiu (http://www.columbia.edu/~jsc19/turntable.html) used VCR heads as idler pulleys (in contact with the platter !!) to add rotational inertia to the platter without adding weight. These heads are apparently quite high quality as far as their bearings are concerned. Johannes has some interesting ideas, and it would be interesting to return to them two months after directing the list to his website. Cheers, Thom ----- Original Message ----- From: Micheal Larosa To: Sent: Friday, February 11, 2000 3:22 AM Subject: My two cents after reading the attached digests After reading through the digests I have a few questions and comments. questions: What size is the thread on the outside of the brass bearing? Will the spindle tips (threaded for clamp and non threaded versions) have flats machined on them to facilitate ease of insertion and removal? Any idea on the diameter of the pulley and idlers? comments: I worked in a plastics shop for three years. during wich i did most of the acrylic work there. Concerning cutting and forming:Cutting is best performed with a table saw and a carbide tipped blade with a two to three deg. negative rake.Care must be taken to feed the saw at the appropriate rate,otherwise binding,melting,or chipping may result.(binding is definitely a problem as 1" acrylic is extremely thick and is not recommended for beginners!)It's also very heavy. I.E. two people are a must when putting a 4'x8' sheet on the table saw! Forming can be done with a typical router and carbide bits used for woodworking, again assuming the proper feed rate so as not to chip or melt the plastic. Half inch shank bits are recommended as acrylic is remarkably tough stuff. Concerning "gluing" acrylic, the primary solvent used is metheleyne chloride, along with some other ingredients to speed up or slow down the setting process, and rid the process of bubbles. This "glue" is the consistency of water and if used properly needs no vacuum process to give excellent bubble free results. IMHO,the group may want to consider, (if they haven't already done so)having a plastics shop in the vicinity of the machinist's location rough cut and laminate the acrylic sheet.Unless of course the machinist is experienced in these things. The "gluing" process is a bit tricky, and poor results are easily achieved.(I speak from experience here.) ;-) Hope this sheds some light on the situation. The acrylic plinths being considered by some in the group can be easily achieved by cutting and shaping a pattern of wood. Use double sided masking tape attach the acrylic to the pattern. Trim closely to within 1/4" of the pattern. and then rout with a flush cut bit on your router table! I welcome any questions and comments ( jolly, rude or otherwise)concerning my sermon here. I would like to offer my greatest thanks for the opportunity to be a benificiary of this great collection of insights and ideas. Michael LaRosa Subject: Re: [teres] Re: My two cents after reading the attached digests Date: Sun, 13 Feb 2000 10:00:06 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com; Stewart Ono; Micheal Larosa Michael, A final(?) followup on your original comments/questions. Last night I returned to an action item I had tabled for this weekend - re-spec'ing the removeable spindles that thread into the bearing. I had noted a couple of changes to Chris two weeks ago when we did a walk-through at his house. One of the changes was that the spindle for the threaded record clamp did *not* reflect the step down from the diameter of the record hole (.280) to the threaded portion which the record clamp screws into (.25" x 20 pitch thread). Chris will be changing these dimensions on the final drawings going out to Bryce. I for one am truly grateful that Chris took on the task of these drawings. He is truly the man for this job - his attention to detail is incredible. This dimensional correction was the only change I found in his drawings. His dimensions were spot on perfect, other than this, and one reason he "slacked off" in this area was because he was waiting for me to travel to various local individuals' houses in order to take as many different spindle measurements as possible as a form of cross validation. I had not completed this task at the time and so he knew that these dimensions would be undergoing a final review. The total height of both of the spindles will be 0.80" which means a net height over the record playing surface of 0.75" (the label rebate is .05" deep). I suspect that this is what generated your question and I thank you for taking the time to review the drawings so carefully. Chris and I have received very little feedback from members of the group on the drawings and dimensions. We have as a result, taken it upon ourselves to do multiple reviews of them. The good news is that we're in the same town, so we weren't limited to e-mail conversations which could really make a review like this cumbersome as well as a test of verbal clarity :-) Cheers, Thom ---- Original Message ----- From: Micheal Larosa To: Sent: Friday, February 11, 2000 3:22 AM Subject: My two cents after reading the attached digests [ snip ] Will the spindle tips (threaded for clamp and non threaded versions) have flats machined on them to facilitate ease of insertion and removal? [ snip ] Michael LaRosa Subject: Re: [teres] Re: My two cents after reading the attached digests Date: Sun, 13 Feb 2000 10:04:50 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com; Stewart Ono; Micheal Larosa Michael, A final(?) followup on your original comments/questions. Last night I returned to an action item I had tabled for this weekend - re-spec'ing the removeable spindles that thread into the bearing. I had noted a couple of changes to Chris two weeks ago when we did a walk-through at his house. One of the changes was that the spindle for the threaded record clamp did *not* reflect the step down from the diameter of the record hole (.280) to the threaded portion which the record clamp screws into (.25" x 20 pitch thread). Chris will be changing these dimensions on the final drawings going out to Bryce. I for one am truly grateful that Chris took on the task of these drawings. He is truly the man for this job - his attention to detail is incredible. This dimensional correction was the only change I found in his drawings. His dimensions were spot on perfect, other than this, and one reason he "slacked off" in this area was because he was waiting for me to travel to various local individuals' houses in order to take as many different spindle measurements as possible as a form of cross validation. I had not completed this task at the time and so he knew that these dimensions would be undergoing a final review. The total height of both of the spindles will be 0.80" which means a net height over the record playing surface of 0.75" (the label rebate is .05" deep). I suspect that this is what generated your question and I thank you for taking the time to review the drawings so carefully. Chris and I have received very little feedback from members of the group on the drawings and dimensions. We have as a result, taken it upon ourselves to do multiple reviews of them. The good news is that we're in the same town, so we weren't limited to e-mail conversations which could really make a review like this cumbersome as well as a test of verbal clarity :-) Cheers, Thom ---- Original Message ----- From: Micheal Larosa To: Sent: Friday, February 11, 2000 3:22 AM Subject: My two cents after reading the attached digests [ snip ] Will the spindle tips (threaded for clamp and non threaded versions) have flats machined on them to facilitate ease of insertion and removal? [ snip ] Michael LaRosa Subject: [teres] Bearing question..off topic Date: Thu, 17 Feb 2000 12:12:33 -0700 From: steve brooks, steve brooks To: teres@aiko.com Gang I am working on a VPI JR. and took apart the bearing today. What I found was something very gelatinious inside..not like the bottle of very liquid bearing oil (they call it grease) I bought from VPI. My question to you bearing experts: Is that what happens to oil that just sits around (this bearing hasn't been used for probably 6 years) or did I screw something up by cleaning that stuff out? Steve Subject: Re: [teres] Sticky Bearing question..off topic Date: Thu, 17 Feb 2000 15:21:53 -0700 From: George Munger, George Munger To: teres@aiko.com I think, that I too, have come across a similar condition in some open-reel tape drive servo mechanisms, where the lube gummed-up over long periods of time (years) and sometimes to the point of malfunction (mechanism dormancy may hasten this condition). The recorder's construction complexity required a labor-intensive dismantling of the tape drive to access the part. After cleaning with pro-grade alcohol (97% pure or better), an oil from a company known then as Westlake Audio, in California was used. Techys had blamed the problem on both an overly volatile lube and a poorly designed mechanism. I finally rid myself of those units and now use wonderful Tandberg TD20As, without this problem. GM >>> "steve brooks" 02/17 4:10 PM >>> Gang I am working on a VPI JR. and took apart the bearing today. What I found was something very gelatinious inside..not like the bottle of very liquid bearing oil (they call it grease) I bought from VPI. My question to you bearing experts: Is that what happens to oil that just sits around (this bearing hasn't been used for probably 6 years) or did I screw something up by cleaning that stuff out? Steve Subject: Re: [teres] Bearing question..off topic Date: Thu, 17 Feb 2000 17:12:29 -0700 From: Scott Fraser, Scott Fraser To: teres@aiko.com According to Brooks Berdan - Mobile One oil is one of the few that won't gel or gum over time. I've tried it on the Scheu platter/bearing and it works as well as he says (although only a year has gone by) Scott >Gang >I am working on a VPI JR. and took apart the bearing today. What I found was >something very gelatinious inside..not like the bottle of very liquid >bearing oil (they call it grease) I bought from VPI. My question to you >bearing experts: Is that what happens to oil that just sits around (this >bearing hasn't been used for probably 6 years) or did I screw something up >by cleaning that stuff out? >Steve = = = = = = = = = = = = = = = = = Scott Fraser (sefraser@caltech.edu) Caltech, Beckman Institute (139-74) Pasadena, CA 91125 626 395-2790 telephone 626 449-5163 fax Subject: Re: [teres] FW: belts Date: Wed, 23 Feb 2000 19:10:34 -0700 From: phclark, phclark To: teres@aiko.com ----- Original Message ----- From: "Ivan Anderson" To: Sent: Wednesday, February 23, 2000 2:51 PM Subject: Re: [teres] FW: belts > Hi there, > > 2 thoughts: > > There could be an issue of the belt (depending on the stickiness of the > material) sticking to the platter at the point where it leaves that and > travels to the pully. I know it has been recommended by some, when using a > flat rubber belt, to put a twist in the belt before installing it over the > pully. This has the effect of peeling the belt off the platter rather than > having an irregular plucking effect. This could not be done with round > cross sectioned belts. > > Could there be some electrostatic effect between belt and platter? Would it > be wise to earth the bearing? > Not a terrible idea, considering the static charge that can magically appear on records themselves. > Ivan. > > Subject: Re: [teres] FW: belts Date: Wed, 23 Feb 2000 21:40:43 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com Good thinking, Ivan My Merrill 'table earths the bearing. It's been a couple of years since I crawled under there. I believe it's earthed to the tonearm mounting bolt. Thom ----- Original Message ----- From: Ivan Anderson To: Sent: Wednesday, February 23, 2000 2:51 PM Subject: Re: [teres] FW: belts Hi there, 2 thoughts: There could be an issue of the belt (depending on the stickiness of the material) sticking to the platter at the point where it leaves that and travels to the pully. I know it has been recommended by some, when using a flat rubber belt, to put a twist in the belt before installing it over the pully. This has the effect of peeling the belt off the platter rather than having an irregular plucking effect. This could not be done with round cross sectioned belts. Could there be some electrostatic effect between belt and platter? Would it be wise to earth the bearing? Ivan. Subject: [teres] demonic acrylic Date: Fri, 3 Mar 2000 05:33:53 -0700 From: Sellek, Grant (TSA), Sellek, Grant (TSA) To: 'Teres List' Did anyone note the recent Stereophile test of some $10,000 turntable which, upon proclaiming it one of the best decks available, put the blame for its few vices squarely on the use of acrylic for the platter? I recall words like "imagine how good it would be with some other platter material". Grant Sellek Adelaide, Australia grant.sellek@transport.sa.gov.au Subject: [Fwd: Plastics] Date: Tue, 21 Mar 2000 20:41:21 -0700 From: Chris Brady, Chris Brady To: tmackris@earthlink.net -------- Original Message -------- From: "Jon Lane" Subject: Plastics To: "Chris Brady" Chris, Briefly, this is list of relative plastic prices per sq ft from a '96 catalog of mine. FOB, Reno, NV. As we knew, laminated acrylic is cost effective, especially in 1". Acrylic, 1", domestic clear $40 Acrylic, 3", domestic clear $210 Acrylic, 3", domestic color $275 UHMW, 1" $28 UHMW, 3" $110 Nylon, 1" $65 Nylon, 3" $180 UHMW, (Ultra High Molecular Weight) is interesting stuff. Tough, easily machined, and sonically inert. A bit slippery and stringy, though, and a dull off-white color; not especially beautiful to look at. But maybe black nylon would work... Jon Lane Subject: Re: [teres] Teres-Bearing & Platter - Progress Report Date: Tue, 21 Mar 2000 21:58:22 -0700 From: MaughanAudio@aol.com, MaughanAudio@aol.com To: teres@aiko.com In a message dated 3/21/00 3:51:45 PM Mountain Standard Time, SCHEIKE@asa.org writes: << Either one piece (3") or color would cost about twice as much, which is what drove our original thinking. Also if we used 3" we would probably have to buy a full 4' X 8' sheet ($3519.36) which may not be cost efficient. Ken >> I already responded to comments and suggestions by Ron W. for a prototype viewing, but I should also state that what I saw from the jpg photos wasn't bad at all. I wonder if a larger circumference would be less or more visible. I'm committed to this design at the paid price and I am comfortable that I will be more than satisfied with the end results. Let's be quick about some decisions and try to stay with the original design of laminating 3 - 1" sheets. I for one do not want any grooves to try to hide a bond. Until again, Gordon. Subject: Re: [teres] Teres-Bearing & Platter - Progress Report Date: Wed, 22 Mar 2000 10:03:09 -0700 From: Thom Mackris, Thom Mackris To: teres@aiko.com Hi Stan, I would agree with you if the following two conditions are true: 1. If the plastic has not already been ordered and committed for. Chris has a call into Bryce to see if there's any way to change the order but I suspect that it's too late. Additionally, I believe that Bryce is out of town for a few days and might not be able to act on this. 2. If partial pieces can be ordered and we are not limited to ordering complete 4x8 sheets. The state of the order is 52 people, I believe - just over two complete sheets. IIRC, 25 circles can be cut out of a 32 sq foot piece - this allowing for the fact that they're slightly oversized to allow for machining. I may have the numbers wrong, but in principle, I know I heard that we'd be just into a new sheet. A little background... When we were researching the project and made the decision to go with 1" pieces, there were anywhere from 6 - 10 people involved in the project. The information we had at that time was that 3" stock was a special order item and had to be purchased in 4 x 8 sheets. Needless to say, we nixed the idea at the time because we'd have a huge amount of "waste" we'd have. If I'm correct, we still need to purchase in whole sheets & the current order status would put us into the beginning of a 3rd sheet - most of it being unused. Hopefully, I'm wrong about this. If this is true and if amortizing the extra acrylic bumps the price by more than the extra $30.00 which I suspect it would, then we'd be violating the trust placed in us by all of those folks who got into this project on a budget. I'd certainly like to explore our options if it's not too late, but at the same time, I'm willing to treat the few bubbles & partially visible seam as mistakes woven into our Persian Rug as a tribute to Allah. The way I see it, this is not all bad news. I truly don't see us stopping here & consider this to be Teres Phase I. Several folks have contacted Chris privately to suggest other materials for a platter. I'm looking at this platter as being a baseline for future testing, and a bargain at that. Cheers, Thom ----- Original Message ----- From: Stanley Goudge To: ; Sent: Wednesday, March 22, 2000 7:59 AM Subject: Re: [teres] Teres-Bearing & Platter - Progress Report According to my calculations for 3" 4' x 8' sheet @ $2300 vs 3 x 1" 4' x 8' @ $400 = about $35 more per platter for 3", plus there would be less labor involved and quality would be more assured. It's a no brainer guys, get the 3". Stan __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Teres-Bearing & Platter - Progress Report Date: Wed, 22 Mar 2000 14:17:25 -0700 From: Stanley Goudge, Stanley Goudge To: teres@aiko.com; teres@aiko.com Yea we could Steve, if well all wanted the Spj type subchassis. I however realize you wouldn't consider a redesign because you haven't thought *yet* of other options. I'm willing to go any route that the group decides. And I was merely suggesting yet another option that *fits* the ever changing situation, as perceived. We gotta be versatile in these group situations, hey I already giving up on a SS chassis and to throw in the towel to the lossies, man that's sacrifice! ;-) Stan At 11:23 AM 3/22/2000 -0700, Steve Zettel wrote: >on 3/22/00 09:45, Stanley Goudge at sgoudge@cisco.com wrote: > >> Hi Thom, >> >> Thanks for giving us some real numbers to look at. Lets see I should be able >> to get >> 3 sheets of 3" for $6000, which divides to $115 for 52pc. The extra material >> can be used for the chassis, I'm thinking right now how cool that Spj looks >> and with solid acrylic we could have it crystal clear. This would make me >> forget >> about SS, for now anyway. Have you seen the new Spj in the april issue >> of Stereopile, WOW!!! I bet it's over $25,000. >> >> Stan >> >Interesting math, Stan. We can get 52 chassis out of the leftover 3rd sheet >of acrylic? > >I personally have a problem paying more for my platter to fund your chassis. > >Steve Z >near Blunt, MT >