Subject: Re: [teres] FW: belts Date: Wed, 23 Feb 2000 01:38:56 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Roscoe, The cloth you describe sounds very much like a rubberized linen cloth used in some hospitals, for wetting problem areas. It (what I ran across) was white, had little or no stretch, and was coated on one side with a white rubber layer. This would constitute a non-stretchy, well damped material which, if used rubber-side-in, would also give the belt great grip on the platter, with very little tension! It would also be very easy to join the ends of, with simple contact cement, which is quite flexible. If it were, further, doubled up by running the join all the way around until the cut ends were contiguous with each other (but on the opposite sides of the strip), there would not even be a thickened area to speak of. Igor --- Roscoe Primrose wrote: > "Sellek, Grant (TSA)" wrote: > > > > forwarded: > > > > -----Original Message----- > > From: Stewart Ono [mailto:audiodir@gte.net] > > Sent: Wednesday, 23 February 2000 3:23 pm > > To: Sellek, Grant (TSA) > > Subject: belts > > > > Hi Grant: > > > > Sorry, but as you know I can't post to Teres yet. > > He should be able to now... > > > > > Micro Seiki favored a silk thread for their top > line TT and Forsell favored > > simple dental floss. Both TT's in my experience > have some slippage, > > especially in the start up mode. > > Leather is great stuff. I used to use a bandsaw > for metal cutting that used > > a leather belt and I could cut 1.5" sheet with the > 3 inch wide belt. Don't > > know how you're going to join the ends other than > glue, and that may have a > > problem with elasticity going over the pulleys. I > believe the old Rek-o-kut > > TT's may have used leather and come to think of it > so did the Edison rolls! > > The original belt from my Rek-o-Kut was some kind of > coated cloth (like > the white cloth first aid tape, but not sticky) that > had essentially no > stretch. > > Peace > -- > Roscoe Primrose > -- mailto:roscoe@aiko.com -- > http://www.aiko.com/roscoe -- > > "Once in a while you get shown the light > In the strangest of places if you look at it right." > Robert Hunter > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: [teres] FW: belts Date: Tue, 22 Feb 2000 23:19:48 -0700 From: Sellek, Grant (TSA), Sellek, Grant (TSA) To: 'teres@aiko.com' forwarded: -----Original Message----- From: Stewart Ono [mailto:audiodir@gte.net] Sent: Wednesday, 23 February 2000 3:23 pm To: Sellek, Grant (TSA) Subject: belts Hi Grant: Sorry, but as you know I can't post to Teres yet. Micro Seiki favored a silk thread for their top line TT and Forsell favored simple dental floss. Both TT's in my experience have some slippage, especially in the start up mode. Leather is great stuff. I used to use a bandsaw for metal cutting that used a leather belt and I could cut 1.5" sheet with the 3 inch wide belt. Don't know how you're going to join the ends other than glue, and that may have a problem with elasticity going over the pulleys. I believe the old Rek-o-kut TT's may have used leather and come to think of it so did the Edison rolls! Stu Subject: Re: [teres] FW: belts Date: Tue, 22 Feb 2000 23:23:52 -0700 From: Roscoe Primrose, Roscoe Primrose To: teres@aiko.com "Sellek, Grant (TSA)" wrote: > > forwarded: > > -----Original Message----- > From: Stewart Ono [mailto:audiodir@gte.net] > Sent: Wednesday, 23 February 2000 3:23 pm > To: Sellek, Grant (TSA) > Subject: belts > > Hi Grant: > > Sorry, but as you know I can't post to Teres yet. He should be able to now... > > Micro Seiki favored a silk thread for their top line TT and Forsell favored > simple dental floss. Both TT's in my experience have some slippage, > especially in the start up mode. > Leather is great stuff. I used to use a bandsaw for metal cutting that used > a leather belt and I could cut 1.5" sheet with the 3 inch wide belt. Don't > know how you're going to join the ends other than glue, and that may have a > problem with elasticity going over the pulleys. I believe the old Rek-o-kut > TT's may have used leather and come to think of it so did the Edison rolls! The original belt from my Rek-o-Kut was some kind of coated cloth (like the white cloth first aid tape, but not sticky) that had essentially no stretch. Peace -- Roscoe Primrose -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe -- "Once in a while you get shown the light In the strangest of places if you look at it right." Robert Hunter Subject: Re: [teres] belts Date: Tue, 22 Feb 2000 23:48:53 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com If you close your eyes and concentrate *real* hard, you'll find that belts will be totally superfuluous on our turntables ... reminds me of the Monty Python skit with the building that began to collapse when people stopped having faith ... sorry for the digression :-)) Seriously folks, this will be a helluva turntable if we can hear audible differences between dental floss / tape (waxed?), string, recording tape, fishing line, etc. One thing we'll all have to be on the lookout for is to attribute changes (for better or worse) to the correct cause. With a non-compliant belt we'll have to be impeccable with belt tension - too much will result in increased radial load on both the motor bearing and the platter bearing, potentially increasing noise - we'll blame the material when it is our setup that is at fault. Was it Dr. Wiliamzig (SP #10) who said that the proper tension is the one which drives the platter at the correct speed with the lowest voltage reading? Maybe we put a cheap volt meter on our motor pods - how retro can you go? Another thought is that perhaps our analog kits should include a light weight spring scale - something that measures in ounces - to check for repeatable belt tension. Fortunately, there are will be a lot of us out there to serve as reality checks on each other. Cheers, Thom ----- Original Message ----- From: Sellek, Grant (TSA) To: Sent: Tuesday, February 22, 2000 10:07 PM Subject: [teres] FW: belts forwarded: -----Original Message----- From: Stewart Ono [mailto:audiodir@gte.net] Sent: Wednesday, 23 February 2000 3:23 pm To: Sellek, Grant (TSA) Subject: belts Hi Grant: Sorry, but as you know I can't post to Teres yet. Micro Seiki favored a silk thread for their top line TT and Forsell favored simple dental floss. Both TT's in my experience have some slippage, especially in the start up mode. Leather is great stuff. I used to use a bandsaw for metal cutting that used a leather belt and I could cut 1.5" sheet with the 3 inch wide belt. Don't know how you're going to join the ends other than glue, and that may have a problem with elasticity going over the pulleys. I believe the old Rek-o-kut TT's may have used leather and come to think of it so did the Edison rolls! Stu Subject: Re: [teres] FW: belts Date: Tue, 22 Feb 2000 23:53:45 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com Serious question ... Really ... What knot do you use on string, floss etc. Is the lump caused by a knot audible? Can string / floss be spliced or glued? I remember seeing one of those "believe it or not" type of TV shows as a kid where some lunatic carved an elaborate sculpture on a grain of rice. Some nut has probably spliced fishing line somewhere, but was he an audio nut? Thom -----Original Message----- From: Stewart Ono [mailto:audiodir@gte.net] Sent: Wednesday, 23 February 2000 3:23 pm Subject: belts Hi Grant: Sorry, but as you know I can't post to Teres yet. Micro Seiki favored a silk thread for their top line TT and Forsell favored simple dental floss. Both TT's in my experience have some slippage, especially in the start up mode. Leather is great stuff. I used to use a bandsaw for metal cutting that used a leather belt and I could cut 1.5" sheet with the 3 inch wide belt. Don't know how you're going to join the ends other than glue, and that may have a problem with elasticity going over the pulleys. I believe the old Rek-o-kut TT's may have used leather and come to think of it so did the Edison rolls! Stu Subject: Re: [teres] FW: belts Date: Wed, 23 Feb 2000 01:59:16 -0700 From: phclark, phclark To: teres@aiko.com Hear, hear. Peter C ----- Original Message ----- From: "Igor Kuznetsoff" To: Sent: Wednesday, February 23, 2000 12:37 AM Subject: Re: [teres] FW: belts > Roscoe, > The cloth you describe sounds very much like a > rubberized linen cloth used in some hospitals, for > wetting problem areas. It (what I ran across) was > white, had little or no stretch, and was coated on one > side with a white rubber layer. This would constitute > a non-stretchy, well damped material which, if used > rubber-side-in, would also give the belt great grip on > the platter, with very little tension! It would also > be very easy to join the ends of, with simple contact > cement, which is quite flexible. If it were, further, > doubled up by running the join all the way around > until the cut ends were contiguous with each other > (but on the opposite sides of the strip), there would > not even be a thickened area to speak of. > > Igor > > > --- Roscoe Primrose wrote: > > "Sellek, Grant (TSA)" wrote: > > > > > > forwarded: > > > > > > -----Original Message----- > > > From: Stewart Ono [mailto:audiodir@gte.net] > > > Sent: Wednesday, 23 February 2000 3:23 pm > > > To: Sellek, Grant (TSA) > > > Subject: belts > > > > > > Hi Grant: > > > > > > Sorry, but as you know I can't post to Teres yet. > > > > He should be able to now... > > > > > > > > Micro Seiki favored a silk thread for their top > > line TT and Forsell favored > > > simple dental floss. Both TT's in my experience > > have some slippage, > > > especially in the start up mode. > > > Leather is great stuff. I used to use a bandsaw > > for metal cutting that used > > > a leather belt and I could cut 1.5" sheet with the > > 3 inch wide belt. Don't > > > know how you're going to join the ends other than > > glue, and that may have a > > > problem with elasticity going over the pulleys. I > > believe the old Rek-o-kut > > > TT's may have used leather and come to think of it > > so did the Edison rolls! > > > > The original belt from my Rek-o-Kut was some kind of > > coated cloth (like > > the white cloth first aid tape, but not sticky) that > > had essentially no > > stretch. > > > > Peace > > -- > > Roscoe Primrose > > -- mailto:roscoe@aiko.com -- > > http://www.aiko.com/roscoe -- > > > > "Once in a while you get shown the light > > In the strangest of places if you look at it right." > > Robert Hunter > > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com > Subject: Re: [teres] FW: belts Date: Wed, 23 Feb 2000 02:21:12 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Weeeeeel... I don't know about the string splice, but, Thom, if you'll think back to our skiing days, you'll recall how they join the ends of stranded steel lift cables.... I remember seeing the process once, from a distance. A high-paid imported specialist actually loosens the ends of the cable he is to join, and *interbraids* the ends together in a special weave to form what is essentially then a continuous loop of steel cable. While this won't work on a monofilament, it should be theoretically possible to micro-adapt the process to dental floss, which is stranded. All you have to do is some industrial espionage, or hack into a major cable company's database for the secret proprietary weave (I understand this is usually considered a trade secret), and you can become the world's first turntable dental floss tycoon. Igor --- Thom Mackris / Joan Panzella wrote: > Serious question ... Really ... What knot do you > use on string, floss etc. > Is the lump caused by a knot audible? Can string / > floss be spliced or > glued? > > I remember seeing one of those "believe it or not" > type of TV shows as a kid > where some lunatic carved an elaborate sculpture on > a grain of rice. Some > nut has probably spliced fishing line somewhere, but > was he an audio nut? > > Thom > > -----Original Message----- > From: Stewart Ono [mailto:audiodir@gte.net] > Sent: Wednesday, 23 February 2000 3:23 pm > Subject: belts > > > Hi Grant: > > Sorry, but as you know I can't post to Teres yet. > > Micro Seiki favored a silk thread for their top line > TT and Forsell favored > simple dental floss. Both TT's in my experience have > some slippage, > especially in the start up mode. > Leather is great stuff. I used to use a bandsaw for > metal cutting that used > a leather belt and I could cut 1.5" sheet with the 3 > inch wide belt. Don't > know how you're going to join the ends other than > glue, and that may have a > problem with elasticity going over the pulleys. I > believe the old Rek-o-kut > TT's may have used leather and come to think of it > so did the Edison rolls! > > Stu > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: RE: belt material, was RE: [teres] synchronous vs. asynchronous motor s; Date: Wed, 23 Feb 2000 09:12:03 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Whatever coupling material we use, we need to consider the splice, if one is required. Thom and I mused about that while skiing last weekend. If we use string, would we want to do a micro-splice using fine tweezers and an eye-loupe, or is a carefully-tied knot adequate? Are there any fly-tiers in our group? As Grant points out, the problem with the coupling material is that it will store energy and release it according to it's elasticity. The frequency at which it does that is inversely proportional to its elasticity: a rubber belt will "boing" at a lower frequency than a string, which will be lower than mag tape. On the other hand, the amplitude of the boinging is proportional to the elasticity. Experimentation with different coupling materials seems to be in order. Ken Ken Schei, P.E. Project Engineer Antarctic Support Associates Email address: scheike@asa.org Phone: 303-643-0163 > -----Original Message----- > From: Sellek, Grant (TSA) [SMTP:Grant.Sellek@transport.sa.gov.au] > Sent: Tuesday, February 22, 2000 8:56 PM > To: 'teres@aiko.com' > Subject: belt material, was RE: [teres] synchronous vs. asynchronous > motor s; > > -----Original Message----- > From: phclark [mailto:phclark@uswest.net] > Subject: Re: [teres] synchronous vs. asynchronous motors > > 2. Elastic coupling is inevitable at some level. Non-compliant materials > like magnetic tape would seem to be preferable to, say, string. > =============================================================== > > Peter, I'm not entirely convinced about this, especially if we concede > that > the motor is not providing effective instantaneous speed correction. I > would > agree with the advantage of non-compliant materials if there were no > tradeoffs, however I reckon the danger of a mag tape drive is that it will > efficiently transmit any motor noise to the platter, either bearing-type > or > brush-type noise. We are trying to reduce that noise at its source with a > good choice of motor, but that doesn't mean we can ignore the tranmission > of > noise through the drivetrain. Like Chris Brady said, take every possible > measure. > > I don't want an elastic coupling either. Who wants the platter going boing > boing on the end of a rubber band? I think this is what Peter and others > who > favour mag tape are trying to avoid. > > So I am in favour of a stiff but lossy drivetrain. Mag tape is stiff but > not > lossy. Rubber is slightly lossy but not stiff. The best candidate that > comes > to mind is string, or cotton thread! Does anyone have a better suggestion > for a stiff, lossy material? What about leather? > > Grant > > Grant Sellek > Adelaide, Australia > grant.sellek@transport.sa.gov.au Subject: RE: [teres] FW: belts Date: Wed, 23 Feb 2000 09:31:05 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Igor: When I had my sailboat, I spliced line regularily by loosening the strands and interweaving them; it's a technique that any good sailor adopts. The process is fairly intuitive, and can be imputed by inspecting the weave of the line being considered. How-to knot books are very common. Doing it on the scale we need would be quite delicate but probably feasible with the proper tools (fine jeweler's tweezers and a 4X to 10X eye loupe), plenty of practice, and patience. I may give it a try. 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: Wednesday, February 23, 2000 1:19 AM > To: teres@aiko.com > Subject: Re: [teres] FW: belts > > Weeeeeel... I don't know about the string splice, but, > Thom, if you'll think back to our skiing days, you'll > recall how they join the ends of stranded steel lift > cables.... I remember seeing the process once, from a > distance. A high-paid imported specialist actually > loosens the ends of the cable he is to join, and > *interbraids* the ends together in a special weave to > form what is essentially then a continuous loop of > steel cable. While this won't work on a monofilament, > it should be theoretically possible to micro-adapt the > process to dental floss, which is stranded. All you > have to do is some industrial espionage, or hack into > a major cable company's database for the secret > proprietary weave (I understand this is usually > considered a trade secret), and you can become the > world's first turntable dental floss tycoon. > > Igor > > --- Thom Mackris / Joan Panzella > wrote: > > Serious question ... Really ... What knot do you > > use on string, floss etc. > > Is the lump caused by a knot audible? Can string / > > floss be spliced or > > glued? > > > > I remember seeing one of those "believe it or not" > > type of TV shows as a kid > > where some lunatic carved an elaborate sculpture on > > a grain of rice. Some > > nut has probably spliced fishing line somewhere, but > > was he an audio nut? > > > > Thom > > > > -----Original Message----- > > From: Stewart Ono [mailto:audiodir@gte.net] > > Sent: Wednesday, 23 February 2000 3:23 pm > > Subject: belts > > > > > > Hi Grant: > > > > Sorry, but as you know I can't post to Teres yet. > > > > Micro Seiki favored a silk thread for their top line > > TT and Forsell favored > > simple dental floss. Both TT's in my experience have > > some slippage, > > especially in the start up mode. > > Leather is great stuff. I used to use a bandsaw for > > metal cutting that used > > a leather belt and I could cut 1.5" sheet with the 3 > > inch wide belt. Don't > > know how you're going to join the ends other than > > glue, and that may have a > > problem with elasticity going over the pulleys. I > > believe the old Rek-o-kut > > TT's may have used leather and come to think of it > > so did the Edison rolls! > > > > Stu > > > > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com Subject: Re: [teres] FW: belts Date: Wed, 23 Feb 2000 10:08:30 -0700 From: Roscoe Primrose, Roscoe Primrose To: teres@aiko.com "Schei, Kenneth" wrote: > > Igor: > > When I had my sailboat, I spliced line regularily by loosening the strands > and interweaving them; it's a technique that any good sailor adopts. The > process is fairly intuitive, and can be imputed by inspecting the weave of > the line being considered. How-to knot books are very common. Doing it on > the scale we need would be quite delicate but probably feasible with the > proper tools (fine jeweler's tweezers and a 4X to 10X eye loupe), plenty of > practice, and patience. I may give it a try. > I'm just using a knot on mine at this point, and havn't heard anything that I could attribute to the knot. Verdier uses one too... I think that unless we use a VERY small pulley (which is bad for other reasons) on the motor it won't be an issue. Peace -- Roscoe Primrose -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe "Once in a while you get shown the light In the strangest of places if you look at it right." Robert Hunter "640K ought to be enough for anybody" , Bill Gates, 1981 Subject: Re: belt material, was RE: [teres] synchronous vs. asynchronous motor s; Date: Wed, 23 Feb 2000 10:17:55 -0700 From: Ron Welborne, Ron Welborne To: teres@aiko.com Flyfishing line might be a good choice since most new designs have some "give" designed into the material and the lines are generally woven. Some are also hollow on the inside thereby providing the possibility of joining the two ends together by the insertion of a flexible dowel of some type. Also, a visit to a fabric store might stir up a few possible fabrics as well as numerous types (and sizes) of thread material. A coated or "waxed" thread would provide some friction. I would think a polymer belt would be the easiest to join either by using superglue or melting the ends together with a flame. It seems to me that if one uses a belt that doesn't stretch (i.e. non rubber) this dictates that the motor assembly must be movable/adjustable in order to obtain the proper tension. Am I correct? Ron Welborne Labs wlabs@ix.netcom.com ph: 303.470.6585 fax: 303.791.5783 website --------------- www.welbornelabs.com ----------------- ----- Original Message ----- From: Schei, Kenneth To: Sent: Wednesday, February 23, 2000 8:13 AM Subject: RE: belt material, was RE: [teres] synchronous vs. asynchronous motor s; > Whatever coupling material we use, we need to consider the splice, if one is > required. Thom and I mused about that while skiing last weekend. If we use > string, would we want to do a micro-splice using fine tweezers and an > eye-loupe, or is a carefully-tied knot adequate? Are there any fly-tiers in > our group? As Grant points out, the problem with the coupling material is > that it will store energy and release it according to it's elasticity. The > frequency at which it does that is inversely proportional to its elasticity: > a rubber belt will "boing" at a lower frequency than a string, which will be > lower than mag tape. On the other hand, the amplitude of the boinging is > proportional to the elasticity. Experimentation with different coupling > materials seems to be in order. > > Ken > > Ken Schei, P.E. > Project Engineer > Antarctic Support Associates > Email address: scheike@asa.org > Phone: 303-643-0163 > > > > > -----Original Message----- > > From: Sellek, Grant (TSA) [SMTP:Grant.Sellek@transport.sa.gov.au] > > Sent: Tuesday, February 22, 2000 8:56 PM > > To: 'teres@aiko.com' > > Subject: belt material, was RE: [teres] synchronous vs. asynchronous > > motor s; > > > > -----Original Message----- > > From: phclark [mailto:phclark@uswest.net] > > Subject: Re: [teres] synchronous vs. asynchronous motors > > > > 2. Elastic coupling is inevitable at some level. Non-compliant materials > > like magnetic tape would seem to be preferable to, say, string. > > =============================================================== > > > > Peter, I'm not entirely convinced about this, especially if we concede > > that > > the motor is not providing effective instantaneous speed correction. I > > would > > agree with the advantage of non-compliant materials if there were no > > tradeoffs, however I reckon the danger of a mag tape drive is that it will > > efficiently transmit any motor noise to the platter, either bearing-type > > or > > brush-type noise. We are trying to reduce that noise at its source with a > > good choice of motor, but that doesn't mean we can ignore the tranmission > > of > > noise through the drivetrain. Like Chris Brady said, take every possible > > measure. > > > > I don't want an elastic coupling either. Who wants the platter going boing > > boing on the end of a rubber band? I think this is what Peter and others > > who > > favour mag tape are trying to avoid. > > > > So I am in favour of a stiff but lossy drivetrain. Mag tape is stiff but > > not > > lossy. Rubber is slightly lossy but not stiff. The best candidate that > > comes > > to mind is string, or cotton thread! Does anyone have a better suggestion > > for a stiff, lossy material? What about leather? > > > > Grant > > > > Grant Sellek > > Adelaide, Australia > > grant.sellek@transport.sa.gov.au Subject: Re: [teres] FW: belts Date: Wed, 23 Feb 2000 10:53:10 -0700 From: phclark, phclark To: teres@aiko.com Ken, I've done my share of splicing. Really, if you can braid, you can splice. I'm a little afraid of this for the application, though, because the splice has to "set." When splicing rope, cables and hawsers (they're all laid up differently) mallets are often used to pound the splice into submission, so to speak. Splices also stretch, until they have "set." There is such a beast as "the long splice," which is actually three separate operations on the same join, which is considered to be equivalent to unjoined line and has the advantage that, if properly executed, is the same size as the joined line (it's used for running through blocks.) I never did acquire the knack of getting, say two loops, the same size. Close, but not precise. Whether this is a big consideration with a movable motor mount, I don't know. At this point in the festivities, I plan to use a movable, at least separate, motor mount, so there would be a modicum of wiggle room for length. Just a few thoughts. Peter C ---- Original Message ----- From: "Schei, Kenneth" To: Sent: Wednesday, February 23, 2000 8:32 AM Subject: RE: [teres] FW: belts > Igor: > > When I had my sailboat, I spliced line regularily by loosening the strands > and interweaving them; it's a technique that any good sailor adopts. The > process is fairly intuitive, and can be imputed by inspecting the weave of > the line being considered. How-to knot books are very common. Doing it on > the scale we need would be quite delicate but probably feasible with the > proper tools (fine jeweler's tweezers and a 4X to 10X eye loupe), plenty of > practice, and patience. I may give it a try. > > 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: Wednesday, February 23, 2000 1:19 AM > > To: teres@aiko.com > > Subject: Re: [teres] FW: belts > > > > Weeeeeel... I don't know about the string splice, but, > > Thom, if you'll think back to our skiing days, you'll > > recall how they join the ends of stranded steel lift > > cables.... I remember seeing the process once, from a > > distance. A high-paid imported specialist actually > > loosens the ends of the cable he is to join, and > > *interbraids* the ends together in a special weave to > > form what is essentially then a continuous loop of > > steel cable. While this won't work on a monofilament, > > it should be theoretically possible to micro-adapt the > > process to dental floss, which is stranded. All you > > have to do is some industrial espionage, or hack into > > a major cable company's database for the secret > > proprietary weave (I understand this is usually > > considered a trade secret), and you can become the > > world's first turntable dental floss tycoon. > > > > Igor > > > > --- Thom Mackris / Joan Panzella > > wrote: > > > Serious question ... Really ... What knot do you > > > use on string, floss etc. > > > Is the lump caused by a knot audible? Can string / > > > floss be spliced or > > > glued? > > > > > > I remember seeing one of those "believe it or not" > > > type of TV shows as a kid > > > where some lunatic carved an elaborate sculpture on > > > a grain of rice. Some > > > nut has probably spliced fishing line somewhere, but > > > was he an audio nut? > > > > > > Thom > > > > > > -----Original Message----- > > > From: Stewart Ono [mailto:audiodir@gte.net] > > > Sent: Wednesday, 23 February 2000 3:23 pm > > > Subject: belts > > > > > > > > > Hi Grant: > > > > > > Sorry, but as you know I can't post to Teres yet. > > > > > > Micro Seiki favored a silk thread for their top line > > > TT and Forsell favored > > > simple dental floss. Both TT's in my experience have > > > some slippage, > > > especially in the start up mode. > > > Leather is great stuff. I used to use a bandsaw for > > > metal cutting that used > > > a leather belt and I could cut 1.5" sheet with the 3 > > > inch wide belt. Don't > > > know how you're going to join the ends other than > > > glue, and that may have a > > > problem with elasticity going over the pulleys. I > > > believe the old Rek-o-kut > > > TT's may have used leather and come to think of it > > > so did the Edison rolls! > > > > > > Stu > > > > > > > > __________________________________________________ > > Do You Yahoo!? > > Talk to your friends online with Yahoo! Messenger. > > http://im.yahoo.com > Subject: RE: [teres] FW: belts Date: Wed, 23 Feb 2000 11:21:24 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Good thoughts, Peter. Maybe we can compromise with a rudimentary micro-splice with a tiny touch of superglue to keep it from unravelling, but not yet becoming a hard spot. Ken > -----Original Message----- > From: phclark [SMTP:phclark@uswest.net] > Sent: Wednesday, February 23, 2000 9:19 AM > To: teres@aiko.com > Subject: Re: [teres] FW: belts > > Ken, > > I've done my share of splicing. Really, if you can braid, you can splice. > I'm a little afraid of this for the application, though, because the > splice > has to "set." When splicing rope, cables and hawsers (they're all laid up > differently) mallets are often used to pound the splice into submission, > so > to speak. Splices also stretch, until they have "set." There is such a > beast as "the long splice," which is actually three separate operations on > the same join, which is considered to be equivalent to unjoined line and > has > the advantage that, if properly executed, is the same size as the joined > line (it's used for running through blocks.) > > I never did acquire the knack of getting, say two loops, the same size. > Close, but not precise. Whether this is a big consideration with a > movable > motor mount, I don't know. At this point in the festivities, I plan to > use > a movable, at least separate, motor mount, so there would be a modicum of > wiggle room for length. Just a few thoughts. > > Peter C > > ---- Original Message ----- > From: "Schei, Kenneth" > To: > Sent: Wednesday, February 23, 2000 8:32 AM > Subject: RE: [teres] FW: belts > > > > Igor: > > > > When I had my sailboat, I spliced line regularily by loosening the > strands > > and interweaving them; it's a technique that any good sailor adopts. > The > > process is fairly intuitive, and can be imputed by inspecting the weave > of > > the line being considered. How-to knot books are very common. Doing > it > on > > the scale we need would be quite delicate but probably feasible with the > > proper tools (fine jeweler's tweezers and a 4X to 10X eye loupe), plenty > of > > practice, and patience. I may give it a try. > > > > 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: Wednesday, February 23, 2000 1:19 AM > > > To: teres@aiko.com > > > Subject: Re: [teres] FW: belts > > > > > > Weeeeeel... I don't know about the string splice, but, > > > Thom, if you'll think back to our skiing days, you'll > > > recall how they join the ends of stranded steel lift > > > cables.... I remember seeing the process once, from a > > > distance. A high-paid imported specialist actually > > > loosens the ends of the cable he is to join, and > > > *interbraids* the ends together in a special weave to > > > form what is essentially then a continuous loop of > > > steel cable. While this won't work on a monofilament, > > > it should be theoretically possible to micro-adapt the > > > process to dental floss, which is stranded. All you > > > have to do is some industrial espionage, or hack into > > > a major cable company's database for the secret > > > proprietary weave (I understand this is usually > > > considered a trade secret), and you can become the > > > world's first turntable dental floss tycoon. > > > > > > Igor > > > > > > --- Thom Mackris / Joan Panzella > > > wrote: > > > > Serious question ... Really ... What knot do you > > > > use on string, floss etc. > > > > Is the lump caused by a knot audible? Can string / > > > > floss be spliced or > > > > glued? > > > > > > > > I remember seeing one of those "believe it or not" > > > > type of TV shows as a kid > > > > where some lunatic carved an elaborate sculpture on > > > > a grain of rice. Some > > > > nut has probably spliced fishing line somewhere, but > > > > was he an audio nut? > > > > > > > > Thom > > > > > > > > -----Original Message----- > > > > From: Stewart Ono [mailto:audiodir@gte.net] > > > > Sent: Wednesday, 23 February 2000 3:23 pm > > > > Subject: belts > > > > > > > > > > > > Hi Grant: > > > > > > > > Sorry, but as you know I can't post to Teres yet. > > > > > > > > Micro Seiki favored a silk thread for their top line > > > > TT and Forsell favored > > > > simple dental floss. Both TT's in my experience have > > > > some slippage, > > > > especially in the start up mode. > > > > Leather is great stuff. I used to use a bandsaw for > > > > metal cutting that used > > > > a leather belt and I could cut 1.5" sheet with the 3 > > > > inch wide belt. Don't > > > > know how you're going to join the ends other than > > > > glue, and that may have a > > > > problem with elasticity going over the pulleys. I > > > > believe the old Rek-o-kut > > > > TT's may have used leather and come to think of it > > > > so did the Edison rolls! > > > > > > > > Stu > > > > > > > > > > > __________________________________________________ > > > Do You Yahoo!? > > > Talk to your friends online with Yahoo! Messenger. > > > http://im.yahoo.com > > Subject: RE: [teres] FW: belts Date: Wed, 23 Feb 2000 13:30:11 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Great! Or, if not super glue, on at least unwaxed floss, or other stranded material, a little contact cement, one of my all-time favorite all- purpose glues wiil work nicely, as it remauns quite flexible. Just be sure to use a minimum, and squeeze out as much of the excess as possible to avoid a stiff spot. Igor --- "Schei, Kenneth" wrote: > Good thoughts, Peter. Maybe we can compromise with > a rudimentary > micro-splice with a tiny touch of superglue to keep > it from unravelling, but > not yet becoming a hard spot. > > Ken > > > > -----Original Message----- > > From: phclark [SMTP:phclark@uswest.net] > > Sent: Wednesday, February 23, 2000 9:19 AM > > To: teres@aiko.com > > Subject: Re: [teres] FW: belts > > > > Ken, > > > > I've done my share of splicing. Really, if you > can braid, you can splice. > > I'm a little afraid of this for the application, > though, because the > > splice > > has to "set." When splicing rope, cables and > hawsers (they're all laid up > > differently) mallets are often used to pound the > splice into submission, > > so > > to speak. Splices also stretch, until they have > "set." There is such a > > beast as "the long splice," which is actually > three separate operations on > > the same join, which is considered to be > equivalent to unjoined line and > > has > > the advantage that, if properly executed, is the > same size as the joined > > line (it's used for running through blocks.) > > > > I never did acquire the knack of getting, say two > loops, the same size. > > Close, but not precise. Whether this is a big > consideration with a > > movable > > motor mount, I don't know. At this point in the > festivities, I plan to > > use > > a movable, at least separate, motor mount, so > there would be a modicum of > > wiggle room for length. Just a few thoughts. > > > > Peter C > > > > ---- Original Message ----- > > From: "Schei, Kenneth" > > To: > > Sent: Wednesday, February 23, 2000 8:32 AM > > Subject: RE: [teres] FW: belts > > > > > > > Igor: > > > > > > When I had my sailboat, I spliced line > regularily by loosening the > > strands > > > and interweaving them; it's a technique that any > good sailor adopts. > > The > > > process is fairly intuitive, and can be imputed > by inspecting the weave > > of > > > the line being considered. How-to knot books > are very common. Doing > > it > > on > > > the scale we need would be quite delicate but > probably feasible with the > > > proper tools (fine jeweler's tweezers and a 4X > to 10X eye loupe), plenty > > of > > > practice, and patience. I may give it a try. > > > > > > 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: Wednesday, February 23, 2000 1:19 AM > > > > To: teres@aiko.com > > > > Subject: Re: [teres] FW: belts > > > > > > > > Weeeeeel... I don't know about the string > splice, but, > > > > Thom, if you'll think back to our skiing days, > you'll > > > > recall how they join the ends of stranded > steel lift > > > > cables.... I remember seeing the process once, > from a > > > > distance. A high-paid imported specialist > actually > > > > loosens the ends of the cable he is to join, > and > > > > *interbraids* the ends together in a special > weave to > > > > form what is essentially then a continuous > loop of > > > > steel cable. While this won't work on a > monofilament, > > > > it should be theoretically possible to > micro-adapt the > > > > process to dental floss, which is stranded. > All you > > > > have to do is some industrial espionage, or > hack into > > > > a major cable company's database for the > secret > > > > proprietary weave (I understand this is > usually > > > > considered a trade secret), and you can become > the > > > > world's first turntable dental floss tycoon. > > > > > > > > Igor > > > > > > > > --- Thom Mackris / Joan Panzella > > > > wrote: > > > > > Serious question ... Really ... What knot > do you > > > > > use on string, floss etc. > > > > > Is the lump caused by a knot audible? Can > string / > > > > > floss be spliced or > > > > > glued? > > > > > > > > > > I remember seeing one of those "believe it > or not" > > > > > type of TV shows as a kid > > > > > where some lunatic carved an elaborate > sculpture on > > > > > a grain of rice. Some > > > > > nut has probably spliced fishing line > somewhere, but > > > > > was he an audio nut? > > > > > > > > > > Thom > > > > > > > > > > -----Original Message----- > > > > > From: Stewart Ono [mailto:audiodir@gte.net] > > > > > Sent: Wednesday, 23 February 2000 3:23 pm > > > > > Subject: belts > > > > > > > > > > > > > > > Hi Grant: > > > > > > > > > > Sorry, but as you know I can't post to Teres > yet. > > > > > > > > > > Micro Seiki favored a silk thread for their > top line > > > > > TT and Forsell favored > > > > > simple dental floss. Both TT's in my > experience have > > > > > some slippage, > > > > > especially in the start up mode. > > > > > Leather is great stuff. I used to use a > bandsaw for > > > > > metal cutting that used > > > > > a leather belt and I could cut 1.5" sheet > with the 3 > > > > > inch wide belt. Don't > > > > > know how you're going to join the ends other > than > > > > > glue, and that may have a > > > > > problem with elasticity going over the > pulleys. I > > > > > believe the old Rek-o-kut > > > > > TT's may have used leather and come to think > of it > > > > > so did the Edison rolls! > > > > > > > > > > Stu > > > > > > > > > > > > > > > __________________________________________________ > > > > Do You Yahoo!? > > > > Talk to your friends online with Yahoo! > Messenger. > > > > http://im.yahoo.com > > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] FW: belts Date: Wed, 23 Feb 2000 15:58:50 -0700 From: Ivan Anderson, Ivan Anderson To: teres@aiko.com 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: RE: [teres] FW: belts Date: Wed, 23 Feb 2000 16:52:03 -0700 From: Schei, Kenneth, Schei, Kenneth To: 'teres@aiko.com' Putting a twist in the belt is also effective to reduce the belt vibrations between the pulley and the platter. Ken > -----Original Message----- > From: Ivan Anderson [SMTP:ivan@win.co.nz] > Sent: Wednesday, February 23, 2000 2:52 PM > To: teres@aiko.com > 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: Re: [teres] FW: belts Date: Wed, 23 Feb 2000 17:53:06 -0700 From: StepHydro@aol.com, StepHydro@aol.com To: teres@aiko.com That's the trick. In the US, Tandy leather stores have tubes of a cement called Barge. It is a super-contact-cement. I believe it is the right stuff for joining belts. Cheers/carron In a message dated 02/23/2000 2: Great! Or, if not super glue, on at least unwaxed > floss, or other stranded material, a little contact > cement, one of my all-time favorite all- purpose glues > wiil work nicely, as it remauns quite flexible. Just > be sure to use a minimum, and squeeze out as much of > the excess as possible to avoid a stiff spot. Subject: [teres] Re: belt material Date: Fri, 25 Feb 2000 03:09:11 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com Hi George, I've been thinking about your comments. My guess is that what we would need to some sort of transducer, like an acoustic guitar pickup which we could place on the subchassis while the various belts are spinning the platter. We could then pass this output through an amplifier and either listen to or measure the results as far as total output and frequency spectrum. I'm guessing that what we learn as far as the correlation between the noise we measure vs. good sound this will be equal combiations of engineering and magic :-)) Perhaps we will learn that some frequency spectrums are more benign and will sound better at a higher level than other frequencies do at a lower value. This would be interesting. This technique would be informative in terms of evaluating various suspension / damping schemes vs. audible results too. I wonder if on a cruder level of inquiry, that vibration levels at this level of sophistication are audible with a plain ol' stethescope? Comments? Cheers, Thom ----- Original Message ----- From: George Munger To: Sent: Wednesday, February 23, 2000 7:33 AM Subject: Re: belt material, was RE: [teres] synchronous vs.asynchronous motors; Hey there. I know not much, but Thom keeps saying to express ourselves so... Isn't there a way(s) we could try to perform some tests to obtain some quantitative data, once a list of possible belt materials is made? A) id the energy transmission levels of various belt materials to an acrylic platter (maybe we don't even need a Teres platter, just an acrylic one). 1) determine the various materials transmission values 2) determine if value changes relate to audible changes 3) determine other factors to check if stiff, lossy, available, etc. We then review the results. We could test an existing rubber TT/belt combo as a reference. Then make/obtain each available belt material, mag-tape, dental floss, etc. using ?? instrument(s) to determine quantitative values, then qualitative (listening) results. All other things being equal, we might get something of value here, maybe not... inquiring minds want to know. What to do? GM >>> "Sellek, Grant (TSA)" 02/22 10:55 PM >>> -----Original Message----- From: phclark [mailto:phclark@uswest.net] Subject: Re: [teres] synchronous vs. asynchronous motors 2. Elastic coupling is inevitable at some level. Non-compliant materials like magnetic tape would seem to be preferable to, say, string. =============================================================== Peter, I'm not entirely convinced about this, especially if we concede that the motor is not providing effective instantaneous speed correction. I would agree with the advantage of non-compliant materials if there were no tradeoffs, however I reckon the danger of a mag tape drive is that it will efficiently transmit any motor noise to the platter, either bearing-type or brush-type noise. We are trying to reduce that noise at its source with a good choice of motor, but that doesn't mean we can ignore the tranmission of noise through the drivetrain. Like Chris Brady said, take every possible measure. I don't want an elastic coupling either. Who wants the platter going boing boing on the end of a rubber band? I think this is what Peter and others who favour mag tape are trying to avoid. So I am in favour of a stiff but lossy drivetrain. Mag tape is stiff but not lossy. Rubber is slightly lossy but not stiff. The best candidate that comes to mind is string, or cotton thread! Does anyone have a better suggestion for a stiff, lossy material? What about leather? Grant Grant Sellek Adelaide, Australia grant.sellek@transport.sa.gov.au Subject: Re: belt material Date: Fri, 25 Feb 2000 03:13:31 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com Hi George, I've been thinking about your comments. My guess is that what we would need to some sort of transducer, like an acoustic guitar pickup which we could place on the subchassis while the various belts are spinning the platter. We could then pass this output through an amplifier and either listen to or measure the results as far as total output and frequency spectrum. I'm guessing that what we learn as far as the correlation between the noise we measure vs. good sound this will be equal combiations of engineering and magic :-)) Perhaps we will learn that some frequency spectrums are more benign and will sound better at a higher level than other frequencies do at a lower value. This would be interesting. This technique would be informative in terms of evaluating various suspension / damping schemes vs. audible results too. I wonder if on a cruder level of inquiry, that vibration levels at this level of sophistication are audible with a plain ol' stethescope? Comments? Cheers, Thom ----- Original Message ----- From: George Munger To: Sent: Wednesday, February 23, 2000 7:33 AM Subject: Re: belt material, was RE: [teres] synchronous vs.asynchronous motors; Hey there. I know not much, but Thom keeps saying to express ourselves so... Isn't there a way(s) we could try to perform some tests to obtain some quantitative data, once a list of possible belt materials is made? A) id the energy transmission levels of various belt materials to an acrylic platter (maybe we don't even need a Teres platter, just an acrylic one). 1) determine the various materials transmission values 2) determine if value changes relate to audible changes 3) determine other factors to check if stiff, lossy, available, etc. We then review the results. We could test an existing rubber TT/belt combo as a reference. Then make/obtain each available belt material, mag-tape, dental floss, etc. using ?? instrument(s) to determine quantitative values, then qualitative (listening) results. All other things being equal, we might get something of value here, maybe not... inquiring minds want to know. What to do? GM >>> "Sellek, Grant (TSA)" 02/22 10:55 PM >>> -----Original Message----- From: phclark [mailto:phclark@uswest.net] Subject: Re: [teres] synchronous vs. asynchronous motors 2. Elastic coupling is inevitable at some level. Non-compliant materials like magnetic tape would seem to be preferable to, say, string. =============================================================== Peter, I'm not entirely convinced about this, especially if we concede that the motor is not providing effective instantaneous speed correction. I would agree with the advantage of non-compliant materials if there were no tradeoffs, however I reckon the danger of a mag tape drive is that it will efficiently transmit any motor noise to the platter, either bearing-type or brush-type noise. We are trying to reduce that noise at its source with a good choice of motor, but that doesn't mean we can ignore the tranmission of noise through the drivetrain. Like Chris Brady said, take every possible measure. I don't want an elastic coupling either. Who wants the platter going boing boing on the end of a rubber band? I think this is what Peter and others who favour mag tape are trying to avoid. So I am in favour of a stiff but lossy drivetrain. Mag tape is stiff but not lossy. Rubber is slightly lossy but not stiff. The best candidate that comes to mind is string, or cotton thread! Does anyone have a better suggestion for a stiff, lossy material? What about leather? Grant Grant Sellek Adelaide, Australia grant.sellek@transport.sa.gov.au Subject: [teres] Re: belt material Date: Fri, 25 Feb 2000 03:15:26 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com Hi Ron, Fly fishing line could have great implications! Another cool thing about flyfishing line is that it has a foam-like coating. Back when I used to slip 'n slide around trout streams, I remember that the ends of the line were tapered, but I believe that the majority of the line was constant diameter. We certainly could come up with interesting possibilities in a fabric store as you also note. We are indeed coming up with many interesting choices! Yes, a non-stretchy belt would imply a motor-pod that is movable in order to adjust tension. I believe the "field knowledge" on this is that it should be loaded with at least 10 lbs of mass in order to keep it from moving around. Small spikes would seem to be an advantage (rubber feet??) to keep it from moving too. Cheers, Thom ----- Original Message ----- From: Ron Welborne To: Sent: Wednesday, February 23, 2000 9:17 AM Subject: Re: belt material, was RE: [teres] synchronous vs. asynchronous motor s; Flyfishing line might be a good choice since most new designs have some "give" designed into the material and the lines are generally woven. Some are also hollow on the inside thereby providing the possibility of joining the two ends together by the insertion of a flexible dowel of some type. Also, a visit to a fabric store might stir up a few possible fabrics as well as numerous types (and sizes) of thread material. A coated or "waxed" thread would provide some friction. I would think a polymer belt would be the easiest to join either by using superglue or melting the ends together with a flame. It seems to me that if one uses a belt that doesn't stretch (i.e. non rubber) this dictates that the motor assembly must be movable/adjustable in order to obtain the proper tension. Am I correct? Ron Welborne Labs wlabs@ix.netcom.com ph: 303.470.6585 fax: 303.791.5783 website --------------- www.welbornelabs.com ----------------- ----- Original Message ----- From: Schei, Kenneth To: Sent: Wednesday, February 23, 2000 8:13 AM Subject: RE: belt material, was RE: [teres] synchronous vs. asynchronous motor s; > Whatever coupling material we use, we need to consider the splice, if one is > required. Thom and I mused about that while skiing last weekend. If we use > string, would we want to do a micro-splice using fine tweezers and an > eye-loupe, or is a carefully-tied knot adequate? Are there any fly-tiers in > our group? As Grant points out, the problem with the coupling material is > that it will store energy and release it according to it's elasticity. The > frequency at which it does that is inversely proportional to its elasticity: > a rubber belt will "boing" at a lower frequency than a string, which will be > lower than mag tape. On the other hand, the amplitude of the boinging is > proportional to the elasticity. Experimentation with different coupling > materials seems to be in order. > > Ken > > Ken Schei, P.E. > Project Engineer > Antarctic Support Associates > Email address: scheike@asa.org > Phone: 303-643-0163 > > > > > -----Original Message----- > > From: Sellek, Grant (TSA) [SMTP:Grant.Sellek@transport.sa.gov.au] > > Sent: Tuesday, February 22, 2000 8:56 PM > > To: 'teres@aiko.com' > > Subject: belt material, was RE: [teres] synchronous vs. asynchronous > > motor s; > > > > -----Original Message----- > > From: phclark [mailto:phclark@uswest.net] > > Subject: Re: [teres] synchronous vs. asynchronous motors > > > > 2. Elastic coupling is inevitable at some level. Non-compliant materials > > like magnetic tape would seem to be preferable to, say, string. > > =============================================================== > > > > Peter, I'm not entirely convinced about this, especially if we concede > > that > > the motor is not providing effective instantaneous speed correction. I > > would > > agree with the advantage of non-compliant materials if there were no > > tradeoffs, however I reckon the danger of a mag tape drive is that it will > > efficiently transmit any motor noise to the platter, either bearing-type > > or > > brush-type noise. We are trying to reduce that noise at its source with a > > good choice of motor, but that doesn't mean we can ignore the tranmission > > of > > noise through the drivetrain. Like Chris Brady said, take every possible > > measure. > > > > I don't want an elastic coupling either. Who wants the platter going boing > > boing on the end of a rubber band? I think this is what Peter and others > > who > > favour mag tape are trying to avoid. > > > > So I am in favour of a stiff but lossy drivetrain. Mag tape is stiff but > > not > > lossy. Rubber is slightly lossy but not stiff. The best candidate that > > comes > > to mind is string, or cotton thread! Does anyone have a better suggestion > > for a stiff, lossy material? What about leather? > > > > Grant > > > > Grant Sellek > > Adelaide, Australia > > grant.sellek@transport.sa.gov.au Subject: RE: [teres] Re: belt material Date: Fri, 25 Feb 2000 09:54:39 -0700 From: Mackris, Thom G., Mackris, Thom G. To: 'teres@aiko.com' Further thoughts... Perhaps the best place to take readings would be at the bearing housing. This would elinate one variable - the damping effects of the subchassis. Thom -----Original Message----- From: Thom Mackris / Joan Panzella [mailto:tmackris@earthlink.net] Sent: Friday, February 25, 2000 2:14 AM To: teres@aiko.com Subject: [teres] Re: belt material Hi George, I've been thinking about your comments. My guess is that what we would need to some sort of transducer, like an acoustic guitar pickup which we could place on the subchassis while the various belts are spinning the platter. We could then pass this output through an amplifier and either listen to or measure the results as far as total output and frequency spectrum. I'm guessing that what we learn as far as the correlation between the noise we measure vs. good sound this will be equal combiations of engineering and magic :-)) Perhaps we will learn that some frequency spectrums are more benign and will sound better at a higher level than other frequencies do at a lower value. This would be interesting. This technique would be informative in terms of evaluating various suspension / damping schemes vs. audible results too. I wonder if on a cruder level of inquiry, that vibration levels at this level of sophistication are audible with a plain ol' stethescope? Comments? Cheers, Thom ----- Original Message ----- From: George Munger To: Sent: Wednesday, February 23, 2000 7:33 AM Subject: Re: belt material, was RE: [teres] synchronous vs.asynchronous motors; Hey there. I know not much, but Thom keeps saying to express ourselves so... Isn't there a way(s) we could try to perform some tests to obtain some quantitative data, once a list of possible belt materials is made? A) id the energy transmission levels of various belt materials to an acrylic platter (maybe we don't even need a Teres platter, just an acrylic one). 1) determine the various materials transmission values 2) determine if value changes relate to audible changes 3) determine other factors to check if stiff, lossy, available, etc. We then review the results. We could test an existing rubber TT/belt combo as a reference. Then make/obtain each available belt material, mag-tape, dental floss, etc. using ?? instrument(s) to determine quantitative values, then qualitative (listening) results. All other things being equal, we might get something of value here, maybe not... inquiring minds want to know. What to do? GM >>> "Sellek, Grant (TSA)" 02/22 10:55 PM >>> -----Original Message----- From: phclark [mailto:phclark@uswest.net] Subject: Re: [teres] synchronous vs. asynchronous motors 2. Elastic coupling is inevitable at some level. Non-compliant materials like magnetic tape would seem to be preferable to, say, string. =============================================================== Peter, I'm not entirely convinced about this, especially if we concede that the motor is not providing effective instantaneous speed correction. I would agree with the advantage of non-compliant materials if there were no tradeoffs, however I reckon the danger of a mag tape drive is that it will efficiently transmit any motor noise to the platter, either bearing-type or brush-type noise. We are trying to reduce that noise at its source with a good choice of motor, but that doesn't mean we can ignore the tranmission of noise through the drivetrain. Like Chris Brady said, take every possible measure. I don't want an elastic coupling either. Who wants the platter going boing boing on the end of a rubber band? I think this is what Peter and others who favour mag tape are trying to avoid. So I am in favour of a stiff but lossy drivetrain. Mag tape is stiff but not lossy. Rubber is slightly lossy but not stiff. The best candidate that comes to mind is string, or cotton thread! Does anyone have a better suggestion for a stiff, lossy material? What about leather? Grant Grant Sellek Adelaide, Australia grant.sellek@transport.sa.gov.au Subject: Re: [teres] Re: belt material Date: Fri, 25 Feb 2000 15:07:49 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com You could even use a cheap, beat up old cartridge as a super-sensitive pickup. Heaven knows, nobody in *this* group would have something like that around.... Igor --- Thom Mackris / Joan Panzella wrote: > Hi George, > > I've been thinking about your comments. My guess is > that what we would need > to some sort of transducer, like an acoustic guitar > pickup which we could > place on the subchassis while the various belts are > spinning the platter. > > We could then pass this output through an amplifier > and either listen to or > measure the results as far as total output and > frequency spectrum. I'm > guessing that what we learn as far as the > correlation between the noise we > measure vs. good sound this will be equal > combiations of engineering and > magic :-)) Perhaps we will learn that some > frequency spectrums are more > benign and will sound better at a higher level than > other frequencies do at > a lower value. This would be interesting. > > This technique would be informative in terms of > evaluating various > suspension / damping schemes vs. audible results > too. > > I wonder if on a cruder level of inquiry, that > vibration levels at this > level of sophistication are audible with a plain ol' > stethescope? > > Comments? > > Cheers, > Thom > > ----- Original Message ----- > From: George Munger > To: > Sent: Wednesday, February 23, 2000 7:33 AM > Subject: Re: belt material, was RE: [teres] > synchronous vs.asynchronous > motors; > > > Hey there. I know not much, but Thom keeps saying > to express ourselves > so... > Isn't there a way(s) we could try to perform some > tests to obtain some > quantitative data, once a list of possible belt > materials is made? > A) id the energy transmission levels of various > belt materials to an > acrylic platter (maybe we don't even need a Teres > platter, just an acrylic > one). > 1) determine the various materials transmission > values > 2) determine if value changes relate to audible > changes > 3) determine other factors to check if stiff, > lossy, available, etc. > We then review the results. We could test an > existing rubber TT/belt combo > as a reference. Then make/obtain each available belt > material, mag-tape, > dental floss, etc. using ?? instrument(s) to > determine quantitative values, > then qualitative (listening) results. All other > things being equal, we > might get something of value here, maybe not... > inquiring minds want to > know. What to do? GM > > >>> "Sellek, Grant (TSA)" > 02/22 10:55 PM > >>> > -----Original Message----- > From: phclark [mailto:phclark@uswest.net] > Subject: Re: [teres] synchronous vs. asynchronous > motors > > 2. Elastic coupling is inevitable at some level. > Non-compliant materials > like magnetic tape would seem to be preferable to, > say, string. > =============================================================== > > Peter, I'm not entirely convinced about this, > especially if we concede that > the motor is not providing effective instantaneous > speed correction. I would > agree with the advantage of non-compliant materials > if there were no > tradeoffs, however I reckon the danger of a mag tape > drive is that it will > efficiently transmit any motor noise to the platter, > either bearing-type or > brush-type noise. We are trying to reduce that noise > at its source with a > good choice of motor, but that doesn't mean we can > ignore the tranmission of > noise through the drivetrain. Like Chris Brady said, > take every possible > measure. > > I don't want an elastic coupling either. Who wants > the platter going boing > boing on the end of a rubber band? I think this is > what Peter and others who > favour mag tape are trying to avoid. > > So I am in favour of a stiff but lossy drivetrain. > Mag tape is stiff but not > lossy. Rubber is slightly lossy but not stiff. The > best candidate that comes > to mind is string, or cotton thread! Does anyone > have a better suggestion > for a stiff, lossy material? What about leather? > > Grant > > Grant Sellek > Adelaide, Australia > grant.sellek@transport.sa.gov.au > > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Belt Tensioning Date: Sat, 26 Feb 2000 00:17:28 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com All, The subject of belt tension & the difficulty of maintaining a consistent value in the absence of belt compliance, should we use any of the number of non-rubber compositions we have been discussing, has suggested to me a couple of simple solutions I would like to advance for consideration. 1) Consistent tension can be arranged easily using a simple pulley & weight arrangement, set up in opposition to the pull of the drive belt. This should be a considerably preferable solution to something like using a spring, which would reintroduce, to some degree, the resonant behavior which we are talking about avoiding by using a non-compliant belt. Simply depending on the mass of the motor pod set up to apply pressure will only cause to the pod to tip awkwardly, not a dependable means of accomplishing this. It will always creep out of adjustment, or the belt will stretch, and even a little of that, and that'll be that. A weight & pulley combo will work much more reliably. To continue with the non-compliant theme, it would also be good to use an equally stretchless, and preferably well damped string to hang the weight. An additional fine point would be to add some simple viscous damping to that system at the pulley. This could be done by arranging some simple means of applying greasy drag to that pulley. Alternately, if the pulley has a smooth working surface, it could be immobilized, or a smooth, relatively large radius right angle bend of some sort is arranged for the string to go over, then even friction will apply some damping, which could be amplified with a little lubricant. Silicone fluid or grease would probably the slick ticket for this unction function. 2) An even tidier, but, I suspect, slightly less effective technique could be arranged using either: a) An arm hanging off the top of the motor pod with a moveable weight arranged much like most arm counterweights. Or: b) A "boom" arm, pivoted at the pod base & angled upwards, with a weight on a string running over it much like a large version of a "Lenco" type anti-skate weight & monofilament-over corkscrew like arm arrangement, could be built onto the pod (only no "corkscrew" is needed for this). Just visualize one of those large construction cranes attached to the side of the motor pod. Either of these would be oriented away from the pull of the belt. With either of these types, we would be depending on the force generated by the weights to tip the motor pod against the pull of the belt in a constant fashion unaffected by creep. These methods are not as easily amenable to additional damping, unless, perhaps something was worked into the base. For any of these arrangements to work reliably, the pod base would have to be designed to allow enough compliance on an axis aligned with motor pulley & platter bearing to allow the weights to do their thing. These systems will automatically compensate for only minor belt stretch, and will require occasional touch up of pod placement. Igor __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Belt Tensioning Date: Sat, 26 Feb 2000 00:39:44 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com The idea of "tippy-ness" of the motor pod, even if ballasted with 10-15 pounds as been bugging my on a subliminal level for some time now, and I've been unable to verbalize it. Well done, Igor! If I understand you correctly, in both examples the weight is being used to balance out the tippy-ness of the motor and therefor to a great extent is controls the belt tension. After thinking about this, I decided to take this idea one step further (who me - extreme?). I considered mounting the motor on a plate which attaches to a separate plate through teflon lined rails. The rails/slots would be aligned with the pull of the belt and the string would be attached to the motor mounting plate. The idea being to tension the belt by sliding the motor assembly along these rails. After considering this for a while, I think I've nixed the idea because I think this would introduce more jitter than it removes. The only reason I'm mentioning it here is because (a) I'm not proud and (b) it might prompt further thought. Cheers, Thom ----- Original Message ----- From: Igor Kuznetsoff To: Sent: Friday, February 25, 2000 11:14 PM Subject: Re: [teres] Belt Tensioning All, The subject of belt tension & the difficulty of maintaining a consistent value in the absence of belt compliance, should we use any of the number of non-rubber compositions we have been discussing, has suggested to me a couple of simple solutions I would like to advance for consideration. 1) Consistent tension can be arranged easily using a simple pulley & weight arrangement, set up in opposition to the pull of the drive belt. This should be a considerably preferable solution to something like using a spring, which would reintroduce, to some degree, the resonant behavior which we are talking about avoiding by using a non-compliant belt. Simply depending on the mass of the motor pod set up to apply pressure will only cause to the pod to tip awkwardly, not a dependable means of accomplishing this. It will always creep out of adjustment, or the belt will stretch, and even a little of that, and that'll be that. A weight & pulley combo will work much more reliably. To continue with the non-compliant theme, it would also be good to use an equally stretchless, and preferably well damped string to hang the weight. An additional fine point would be to add some simple viscous damping to that system at the pulley. This could be done by arranging some simple means of applying greasy drag to that pulley. Alternately, if the pulley has a smooth working surface, it could be immobilized, or a smooth, relatively large radius right angle bend of some sort is arranged for the string to go over, then even friction will apply some damping, which could be amplified with a little lubricant. Silicone fluid or grease would probably the slick ticket for this unction function. 2) An even tidier, but, I suspect, slightly less effective technique could be arranged using either: a) An arm hanging off the top of the motor pod with a moveable weight arranged much like most arm counterweights. Or: b) A "boom" arm, pivoted at the pod base & angled upwards, with a weight on a string running over it much like a large version of a "Lenco" type anti-skate weight & monofilament-over corkscrew like arm arrangement, could be built onto the pod (only no "corkscrew" is needed for this). Just visualize one of those large construction cranes attached to the side of the motor pod. Either of these would be oriented away from the pull of the belt. With either of these types, we would be depending on the force generated by the weights to tip the motor pod against the pull of the belt in a constant fashion unaffected by creep. These methods are not as easily amenable to additional damping, unless, perhaps something was worked into the base. For any of these arrangements to work reliably, the pod base would have to be designed to allow enough compliance on an axis aligned with motor pulley & platter bearing to allow the weights to do their thing. These systems will automatically compensate for only minor belt stretch, and will require occasional touch up of pod placement. Igor __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Belt Tensioning Date: Sat, 26 Feb 2000 01:03:28 -0700 From: FJALLES@aol.com, FJALLES@aol.com To: teres@aiko.com In a message dated 2/26/00 1:44:34 AM Eastern Standard Time, tmackris@earthlink.net writes: > After thinking about this, I decided to take this idea one step further (who > me - extreme?). I considered mounting the motor on a plate which attaches > to a separate plate through teflon lined rails. The rails/slots would be > aligned with the pull of the belt and the string would be attached to the > motor mounting plate. The idea being to tension the belt by sliding the > motor assembly along these rails. Hmmm, that's an interesting idea. I wonder if it would be possible to mount the motor via the platform/rails Thom suggested -- sort of a "sled" arrangement with an air-bearing for the sled rails (good for isolation). Then you could drain off a few PSI to provide a specific tension on the belt.... Best, Frank Subject: Re: [teres] Belt Tensioning Date: Sat, 26 Feb 2000 01:56:17 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com U gots dat roight! Also the part about jitter, I suspect. Decoupling the motor from the vibration sinking mass & smoothing effect of the motor pod could allow a lot more motor vibration to transfer to the drive belt. Best to use the outlined balancing scheme for just that-guaranteeing constant, easily controllable tension and, not to be underestimated, **traction**. Slippage at either pulley or platter could introduce FM distortion ("analog jitter", if you like). This would be all the more insidious for being difficult to pinpoint the cause of. A combination of this balancing scheme, and a half twist (no shake, no stir) in the belt should guarantee good, steady power transmission, and your turntable will never have to visit Lee Myles. Igor --- Thom Mackris / Joan Panzella wrote: > The idea of "tippy-ness" of the motor pod, even if > ballasted with 10-15 > pounds as been bugging my on a subliminal level for > some time now, and I've > been unable to verbalize it. Well done, Igor! > > If I understand you correctly, in both examples the > weight is being used to > balance out the tippy-ness of the motor and therefor > to a great extent is > controls the belt tension. > > After thinking about this, I decided to take this > idea one step further (who > me - extreme?). I considered mounting the motor on > a plate which attaches > to a separate plate through teflon lined rails. The > rails/slots would be > aligned with the pull of the belt and the string > would be attached to the > motor mounting plate. The idea being to tension the > belt by sliding the > motor assembly along these rails. After considering > this for a while, I > think I've nixed the idea because I think this would > introduce more jitter > than it removes. The only reason I'm mentioning it > here is because (a) I'm > not proud and (b) it might prompt further thought. > > Cheers, > Thom > > ----- Original Message ----- > From: Igor Kuznetsoff > To: > Sent: Friday, February 25, 2000 11:14 PM > Subject: Re: [teres] Belt Tensioning > > > All, > The subject of belt tension & the difficulty > of maintaining a consistent value in the absence of > belt compliance, should we use any of the number of > non-rubber compositions we have been discussing, has > suggested to me a couple of simple solutions I would > like to advance for consideration. > > 1) Consistent tension can be arranged easily using > a > simple pulley & weight arrangement, set up in > opposition to the pull of the drive belt. This > should > be a considerably preferable solution to something > like using a spring, which would reintroduce, to > some > degree, the resonant behavior which we are talking > about avoiding by using a non-compliant belt. > Simply > depending on the mass of the motor pod set up to > apply > pressure will only cause to the pod to tip > awkwardly, > not a dependable means of accomplishing this. It > will > always creep out of adjustment, or the belt will > stretch, and even a little of that, and that'll be > that. A weight & pulley combo will work much more > reliably. To continue with the non-compliant theme, > it would also be good to use an equally stretchless, > and preferably well damped string to hang the > weight. > An additional fine point would be to add some simple > viscous damping to that system at the pulley. This > could be done by arranging some simple means of > applying greasy drag to that pulley. Alternately, > if > the pulley has a smooth working surface, it could be > immobilized, or a smooth, relatively large radius > right angle bend of some sort is arranged for the > string to go over, then even friction will apply > some > damping, which could be amplified with a little > lubricant. Silicone fluid or grease would probably > the slick ticket for this unction function. > > 2) An even tidier, but, I suspect, slightly less > effective technique could be arranged using either: > a) An arm hanging off the top of the motor pod with > a > moveable weight arranged much like most arm > counterweights. Or: b) A "boom" arm, pivoted at > the > pod base & angled upwards, with a weight on a string > running over it much like a large version of a > "Lenco" > type anti-skate weight & monofilament-over corkscrew > like arm arrangement, could be built onto the pod > (only no "corkscrew" is needed for this). Just > visualize one of those large construction cranes > attached to the side of the motor pod. Either of > these would be oriented away from the pull of the > belt. With either of these types, we would be > depending on the force generated by the weights to > tip > the motor pod against the pull of the belt in a > constant fashion unaffected by creep. These methods > are not as easily amenable to additional damping, > unless, perhaps something was worked into the base. > > For any of these arrangements to work reliably, the > pod base would have to be designed to allow enough > compliance on an axis aligned with motor pulley & > platter bearing to allow the weights to do their > thing. These systems will automatically compensate > for only minor belt stretch, and will require > occasional touch up of pod placement. > > Igor > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Belt Tensioning Date: Sat, 26 Feb 2000 02:11:16 -0700 From: phclark, phclark To: teres@aiko.com Hmmph. Myself, I'm attracted to the idea of an idler. The notion of using a weight, rather than a more conventional spring, seems the best way to implement the force to be applied, as it is passive. I envision a simple mechanism not unlike a balance scale ( I suppose you could actually use one, certainly the weights) with a roller (using a suitable bearing) mounted on a piston-like affair on the business end to contact the "belt." If you made the assembly heavy "enough," it would not have to be fastened to the plinth and could be placed in a variety of locations. Conceptually, this has the advantage of simplicity over rails, etc. The tension can be applied on the leading or trailing side of the drive, at will. With a longer "belt" it could also be utilized to increase the contact patch on the platter without the use of other monkey motion. I'll steal an idea Mike Larosa mentioned to me the other night in a phone conversation... An appropriately positioned idler 180 degrees from the motor, with sufficient tension, would afford two contact patches on the platter (albeit smaller,) the tangents of which would be 180 degrees apart on the platter bearing. This has the advantage of substantially unloading the platter bearing from lateral stress, surely a Good Thing. This approach would require a "tacky" belt, but this alternative is already under discussion. My $0.02. Peter C Subject: Re: [teres] Belt Tensioning Date: Sat, 26 Feb 2000 02:33:54 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Welcome, Frank It's possible, but you would jeopardize the ability of the motor pod's mass to sink motor vibration. We've had some interesting concepts on that subject during the past week, oil & lead balls & all. Also please see my other post on this subject, with the other "tensioning" post I saw first. Igor --- Thom Mackris / Joan Panzella wrote: > You belong on this list Frank :-)) > > > ----- Original Message ----- > From: > To: > Sent: Saturday, February 26, 2000 12:01 AM > Subject: Re: [teres] Belt Tensioning > > > In a message dated 2/26/00 1:44:34 AM Eastern > Standard Time, > tmackris@earthlink.net writes: > > > After thinking about this, I decided to take this > idea one step further > (who > > me - extreme?). I considered mounting the motor > on a plate which > attaches > > to a separate plate through teflon lined rails. > The rails/slots would be > > aligned with the pull of the belt and the string > would be attached to the > > motor mounting plate. The idea being to tension > the belt by sliding the > > motor assembly along these rails. > > Hmmm, that's an interesting idea. I wonder if it > would be possible to > mount > the motor via the platform/rails Thom suggested -- > sort of a "sled" > arrangement with an air-bearing for the sled rails > (good for isolation). > Then you could drain off a few PSI to provide a > specific tension on the > belt.... > > Best, > Frank > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Belt Tensioning Date: Sat, 26 Feb 2000 02:57:15 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Peter, There is quite a passel o' posts on the idea of idlers in distributed drive systems discussed extensively earlier in this project, including even some early discussion concerning how to build them practically, and even some possibilities for bearings that might be adaptable for the purpose. The possibility of a sub-chassis carrying the idler(s) and allowing the tuning of their location to tune out harmonic behavior attributable to the belts, belt spacing and even the sequential compliance effects of the transmissive system have all been flogged around already. Just check back through the first one or two hundred posts, or so. [ :-) ]. And yes, they are an excellent idea. Igor --- phclark wrote: > Hmmph. > > Myself, I'm attracted to the idea of an idler. The > notion of using a > weight, rather than a more conventional spring, > seems the best way to > implement the force to be applied, as it is passive. > I envision a simple > mechanism not unlike a balance scale ( I suppose you > could actually use one, > certainly the weights) with a roller (using a > suitable bearing) mounted on a > piston-like affair on the business end to contact > the "belt." If you made > the assembly heavy "enough," it would not have to be > fastened to the plinth > and could be placed in a variety of locations. > > Conceptually, this has the advantage of simplicity > over rails, etc. The > tension can be applied on the leading or trailing > side of the drive, at > will. With a longer "belt" it could also be > utilized to increase the > contact patch on the platter without the use of > other monkey motion. > > I'll steal an idea Mike Larosa mentioned to me the > other night in a phone > conversation... An appropriately positioned idler > 180 degrees from the > motor, with sufficient tension, would afford two > contact patches on the > platter (albeit smaller,) the tangents of which > would be 180 degrees apart > on the platter bearing. This has the advantage of > substantially unloading > the platter bearing from lateral stress, surely a > Good Thing. This approach > would require a "tacky" belt, but this alternative > is already under > discussion. > > My $0.02. > > Peter C > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Belt Tensioning Date: Sat, 26 Feb 2000 09:54:05 -0700 From: phclark, phclark To: teres@aiko.com Sorry to go over plowed ground. The size of the earlier digests was too daunting... My bad. Peter C ----- Original Message ----- From: "Igor Kuznetsoff" To: Sent: Saturday, February 26, 2000 1:55 AM Subject: Re: [teres] Belt Tensioning > Peter, > There is quite a passel o' posts on the idea of > idlers in distributed drive systems discussed > extensively earlier in this project, including even > some early discussion concerning how to build them > practically, and even some possibilities for bearings > that might be adaptable for the purpose. > The possibility of a sub-chassis carrying the idler(s) > and allowing the tuning of their location to tune out > harmonic behavior attributable to the belts, belt > spacing and even the sequential compliance effects of > the transmissive system have all been flogged around > already. Just check back through the first one or two > hundred posts, or so. [ :-) ]. And yes, they are an > excellent idea. > > Igor > > > --- phclark wrote: > > Hmmph. > > > > Myself, I'm attracted to the idea of an idler. The > > notion of using a > > weight, rather than a more conventional spring, > > seems the best way to > > implement the force to be applied, as it is passive. > > I envision a simple > > mechanism not unlike a balance scale ( I suppose you > > could actually use one, > > certainly the weights) with a roller (using a > > suitable bearing) mounted on a > > piston-like affair on the business end to contact > > the "belt." If you made > > the assembly heavy "enough," it would not have to be > > fastened to the plinth > > and could be placed in a variety of locations. > > > > Conceptually, this has the advantage of simplicity > > over rails, etc. The > > tension can be applied on the leading or trailing > > side of the drive, at > > will. With a longer "belt" it could also be > > utilized to increase the > > contact patch on the platter without the use of > > other monkey motion. > > > > I'll steal an idea Mike Larosa mentioned to me the > > other night in a phone > > conversation... An appropriately positioned idler > > 180 degrees from the > > motor, with sufficient tension, would afford two > > contact patches on the > > platter (albeit smaller,) the tangents of which > > would be 180 degrees apart > > on the platter bearing. This has the advantage of > > substantially unloading > > the platter bearing from lateral stress, surely a > > Good Thing. This approach > > would require a "tacky" belt, but this alternative > > is already under > > discussion. > > > > My $0.02. > > > > Peter C > > > > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com > Subject: Re: [teres] Belt Tensioning Date: Sat, 26 Feb 2000 11:34:05 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com No biggie Peter. We never did come to full agreement because our main focus at the time was bearing and platter design when this came up. You'll find the stuff in the subchassis digests. I was torn as to how to categorize this topic and finally, I decided that minimally, the subchassis design would have to allow for positioning of idler pulleys. The point we reached was that many will opt for this and some will fear that they can't or are aren't willing to do what it takes to make certean that any noise introduced by additional pulleys is less than the positive effect of pull on the bearingthe bearing shaft. This will surface again ... shortly :-) Thom ----- Original Message ----- From: phclark To: Sent: Saturday, February 26, 2000 8:47 AM Subject: Re: [teres] Belt Tensioning Sorry to go over plowed ground. The size of the earlier digests was too daunting... My bad. Peter C ----- Original Message ----- From: "Igor Kuznetsoff" To: Sent: Saturday, February 26, 2000 1:55 AM Subject: Re: [teres] Belt Tensioning > Peter, > There is quite a passel o' posts on the idea of > idlers in distributed drive systems discussed > extensively earlier in this project, including even > some early discussion concerning how to build them > practically, and even some possibilities for bearings > that might be adaptable for the purpose. > The possibility of a sub-chassis carrying the idler(s) > and allowing the tuning of their location to tune out > harmonic behavior attributable to the belts, belt > spacing and even the sequential compliance effects of > the transmissive system have all been flogged around > already. Just check back through the first one or two > hundred posts, or so. [ :-) ]. And yes, they are an > excellent idea. > > Igor > > > --- phclark wrote: > > Hmmph. > > > > Myself, I'm attracted to the idea of an idler. The > > notion of using a > > weight, rather than a more conventional spring, > > seems the best way to > > implement the force to be applied, as it is passive. > > I envision a simple > > mechanism not unlike a balance scale ( I suppose you > > could actually use one, > > certainly the weights) with a roller (using a > > suitable bearing) mounted on a > > piston-like affair on the business end to contact > > the "belt." If you made > > the assembly heavy "enough," it would not have to be > > fastened to the plinth > > and could be placed in a variety of locations. > > > > Conceptually, this has the advantage of simplicity > > over rails, etc. The > > tension can be applied on the leading or trailing > > side of the drive, at > > will. With a longer "belt" it could also be > > utilized to increase the > > contact patch on the platter without the use of > > other monkey motion. > > > > I'll steal an idea Mike Larosa mentioned to me the > > other night in a phone > > conversation... An appropriately positioned idler > > 180 degrees from the > > motor, with sufficient tension, would afford two > > contact patches on the > > platter (albeit smaller,) the tangents of which > > would be 180 degrees apart > > on the platter bearing. This has the advantage of > > substantially unloading > > the platter bearing from lateral stress, surely a > > Good Thing. This approach > > would require a "tacky" belt, but this alternative > > is already under > > discussion. > > > > My $0.02. > > > > Peter C > > > > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com > Subject: Re: [teres] Re: belt material Date: Sat, 26 Feb 2000 17:26:00 -0700 From: MaughanAudio@aol.com, MaughanAudio@aol.com To: teres@aiko.com Silk ribbon is available at fabric stores and that may be a interesting candidate. The belt material of choice may have implecations on the pulley profile, for example fly fishing line would dictate a deep "v" or "U" profile where a ribbon would dictate a a convex wide profile so that the ribbon would self center. Subject: Re: [teres] Re: belt material Date: Sat, 26 Feb 2000 17:31:56 -0700 From: MaughanAudio@aol.com, MaughanAudio@aol.com To: teres@aiko.com Go to http://libinst.com/accel.htm for Liberty Instruments site on using Accelerometers with Laud. I have this software that I use with loudspeaker analysis and for the money it can't be beat. Subject: Re: [teres] Re: belt material Date: Sat, 26 Feb 2000 23:29:16 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com Funny you should be thinking about this today, Gordon. Chris and I had a conversation today about pulley shapes. I'm wondering if we want to have a multi purpose pulley - essentially two (or even three) sections, one with a groove for increased contact area with string/flyline, and one with a convex shape as you describe. Perhaps even a third area which is flat. I wonder if this is possible on a Maxon spindle. Might this put too much radial force on the motor's bearing? If we had to commit to a single pulley profile, not knowing what material we'd end up using for a belt, would it be flat? Convex? Thom ----- Original Message ----- From: To: Sent: Saturday, February 26, 2000 4:21 PM Subject: Re: [teres] Re: belt material Silk ribbon is available at fabric stores and that may be a interesting candidate. The belt material of choice may have implecations on the pulley profile, for example fly fishing line would dictate a deep "v" or "U" profile where a ribbon would dictate a a convex wide profile so that the ribbon would self center. Subject: Re: [teres] Re: belt material Date: Sat, 26 Feb 2000 23:33:15 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Good point. Been meaning to bring this up. Rubber belts use the convex type, as you mention. Maybe we'll need custom lathed pulleys with both profiles machined into the same one for total flexibility. Igor --- MaughanAudio@aol.com wrote: > Silk ribbon is available at fabric stores and that > may be a interesting > candidate. The belt material of choice may have > implecations on the pulley > profile, for example fly fishing line would dictate > a deep "v" or "U" profile > where a ribbon would dictate a a convex wide profile > so that the ribbon would > self center. > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Re: belt material Date: Sat, 26 Feb 2000 23:51:52 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Synchronicity, I was meaning to bring that up as well. There needn't be a problem with radial force. I assume that you are concerned about the pulley becoming too long, and gaining too much leverage against the motor bearing. To avoid that, we could just install the pulley with profile we want to use closest to the motor, reverse that to change to the other profile. But why commit to a single profile? CNC machining, once programmed will cut an extra wiggle as easily as an end flange or a flat spot, its only a matter of specification, I would think. Igor --- Thom Mackris / Joan Panzella wrote: > Funny you should be thinking about this today, > Gordon. Chris and I had a > conversation today about pulley shapes. > > I'm wondering if we want to have a multi purpose > pulley - essentially two > (or even three) sections, one with a groove for > increased contact area with > string/flyline, and one with a convex shape as you > describe. Perhaps even a > third area which is flat. I wonder if this is > possible on a Maxon spindle. > Might this put too much radial force on the motor's > bearing? > > If we had to commit to a single pulley profile, not > knowing what material > we'd end up using for a belt, would it be flat? > Convex? > > Thom > > ----- Original Message ----- > From: > To: > Sent: Saturday, February 26, 2000 4:21 PM > Subject: Re: [teres] Re: belt material > > > Silk ribbon is available at fabric stores and that > may be a interesting > candidate. The belt material of choice may have > implecations on the pulley > profile, for example fly fishing line would dictate > a deep "v" or "U" > profile > where a ribbon would dictate a a convex wide profile > so that the ribbon > would > self center. > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Re: belt material Date: Sun, 27 Feb 2000 00:02:32 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com Just have a small gear puller in stock to remove and reverse ... ----- Original Message ----- From: Igor Kuznetsoff To: Sent: Saturday, February 26, 2000 10:50 PM Subject: Re: [teres] Re: belt material Synchronicity, I was meaning to bring that up as well. There needn't be a problem with radial force. I assume that you are concerned about the pulley becoming too long, and gaining too much leverage against the motor bearing. To avoid that, we could just install the pulley with profile we want to use closest to the motor, reverse that to change to the other profile. But why commit to a single profile? CNC machining, once programmed will cut an extra wiggle as easily as an end flange or a flat spot, its only a matter of specification, I would think. Igor --- Thom Mackris / Joan Panzella wrote: > Funny you should be thinking about this today, > Gordon. Chris and I had a > conversation today about pulley shapes. > > I'm wondering if we want to have a multi purpose > pulley - essentially two > (or even three) sections, one with a groove for > increased contact area with > string/flyline, and one with a convex shape as you > describe. Perhaps even a > third area which is flat. I wonder if this is > possible on a Maxon spindle. > Might this put too much radial force on the motor's > bearing? > > If we had to commit to a single pulley profile, not > knowing what material > we'd end up using for a belt, would it be flat? > Convex? > > Thom > > ----- Original Message ----- > From: > To: > Sent: Saturday, February 26, 2000 4:21 PM > Subject: Re: [teres] Re: belt material > > > Silk ribbon is available at fabric stores and that > may be a interesting > candidate. The belt material of choice may have > implecations on the pulley > profile, for example fly fishing line would dictate > a deep "v" or "U" > profile > where a ribbon would dictate a a convex wide profile > so that the ribbon > would > self center. > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Re: Sure Looks Like a Scheu to Me Date: Sun, 27 Feb 2000 00:14:41 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Combining a voltmeter with a finely controllable belt tensioning scheme such as one of the possibilities I outlined the other day should result in a most easily & repeatedly optimizable system with the least FM type transmission originated distortion (meaning the steadiest rotational speed at the platter). Igor --- Thom Mackris / Joan Panzella wrote: > When I sent the first link out (below), I didn't > realize that they have > three distinct lines of 'tables: > > (1) Euro-Kits > (2) Amazon > (3) Verdier > > The Amazon reference at $11K bears a striking > resemblence to the "simple" > drawing on Chris' website. Note that the motor > controller incorporates a > suggestion I made, to include a voltmeter. > Obviously, they too are of the > Dr. Wilimzig school that the correct belt (string) > tension is the one which > maintains platter speed at the lowest voltage. This > would certainly make > setup simpler and easily repeatbable. > > This is all coming together! > > Thom > > ----- Original Message ----- > From: Thom Mackris / Joan Panzella > > To: Teres_List > Sent: Saturday, February 26, 2000 5:24 PM > Subject: Sure Looks Like a Scheu to Me > > > The audioadvancements 'tables sure resemble a Scheu > to me. > > http://www.audioadvancements.com/ > > Thom > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Re: belt material Date: Sun, 27 Feb 2000 00:54:26 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com I wonder how hard (as in the shaft material) it would be to thread the motor shaft so that we could just screw the pulley on... Igor --- Thom Mackris / Joan Panzella wrote: > Just have a small gear puller in stock to remove and > reverse ... > > > ----- Original Message ----- > From: Igor Kuznetsoff > To: > Sent: Saturday, February 26, 2000 10:50 PM > Subject: Re: [teres] Re: belt material > > > Synchronicity, I was meaning to bring that up as > well. > There needn't be a problem with radial force. I > assume > that you are concerned about the pulley becoming too > long, and gaining too much leverage against the > motor > bearing. To avoid that, we could just install the > pulley with profile we want to use closest to the > motor, reverse that to change to the other profile. > But why commit to a single profile? CNC machining, > once programmed will cut an extra wiggle as easily > as > an end flange or a flat spot, its only a matter of > specification, I would think. > > Igor > > --- Thom Mackris / Joan Panzella > wrote: > > Funny you should be thinking about this today, > > Gordon. Chris and I had a > > conversation today about pulley shapes. > > > > I'm wondering if we want to have a multi purpose > > pulley - essentially two > > (or even three) sections, one with a groove for > > increased contact area with > > string/flyline, and one with a convex shape as you > > describe. Perhaps even a > > third area which is flat. I wonder if this is > > possible on a Maxon spindle. > > Might this put too much radial force on the > motor's > > bearing? > > > > If we had to commit to a single pulley profile, > not > > knowing what material > > we'd end up using for a belt, would it be flat? > > Convex? > > > > Thom > > > > ----- Original Message ----- > > From: > > To: > > Sent: Saturday, February 26, 2000 4:21 PM > > Subject: Re: [teres] Re: belt material > > > > > > Silk ribbon is available at fabric stores and that > > may be a interesting > > candidate. The belt material of choice may have > > implecations on the pulley > > profile, for example fly fishing line would > dictate > > a deep "v" or "U" > > profile > > where a ribbon would dictate a a convex wide > profile > > so that the ribbon > > would > > self center. > > > > > > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Re: belt material Date: Sun, 27 Feb 2000 00:55:29 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com P.S.-As I pressed send, it occurred to me it would have to be left-hand (reverse) threaded... Igor --- Thom Mackris / Joan Panzella wrote: > Just have a small gear puller in stock to remove and > reverse ... > > > ----- Original Message ----- > From: Igor Kuznetsoff > To: > Sent: Saturday, February 26, 2000 10:50 PM > Subject: Re: [teres] Re: belt material > > > Synchronicity, I was meaning to bring that up as > well. > There needn't be a problem with radial force. I > assume > that you are concerned about the pulley becoming too > long, and gaining too much leverage against the > motor > bearing. To avoid that, we could just install the > pulley with profile we want to use closest to the > motor, reverse that to change to the other profile. > But why commit to a single profile? CNC machining, > once programmed will cut an extra wiggle as easily > as > an end flange or a flat spot, its only a matter of > specification, I would think. > > Igor > > --- Thom Mackris / Joan Panzella > wrote: > > Funny you should be thinking about this today, > > Gordon. Chris and I had a > > conversation today about pulley shapes. > > > > I'm wondering if we want to have a multi purpose > > pulley - essentially two > > (or even three) sections, one with a groove for > > increased contact area with > > string/flyline, and one with a convex shape as you > > describe. Perhaps even a > > third area which is flat. I wonder if this is > > possible on a Maxon spindle. > > Might this put too much radial force on the > motor's > > bearing? > > > > If we had to commit to a single pulley profile, > not > > knowing what material > > we'd end up using for a belt, would it be flat? > > Convex? > > > > Thom > > > > ----- Original Message ----- > > From: > > To: > > Sent: Saturday, February 26, 2000 4:21 PM > > Subject: Re: [teres] Re: belt material > > > > > > Silk ribbon is available at fabric stores and that > > may be a interesting > > candidate. The belt material of choice may have > > implecations on the pulley > > profile, for example fly fishing line would > dictate > > a deep "v" or "U" > > profile > > where a ribbon would dictate a a convex wide > profile > > so that the ribbon > > would > > self center. > > > > > > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Motor & Controller Date: Sun, 27 Feb 2000 07:22:21 -0700 From: StepHydro@aol.com, StepHydro@aol.com To: teres@aiko.com In a message dated 02/27/2000 2: For the pulley material I am thinking aluminum or acrylic. For the string-drive guys, there might be a wear problem. How might acrylic stand up to string slippage? Cheers/Carron Subject: Re: [teres] Motor & Controller Date: Sun, 27 Feb 2000 11:03:20 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Practical thoughts, Manfred. Perhaps we should adopt a policy of automatically giving the platter a helping hand on startup to avoid the wear you mention, as well as the stress that would affect everything including the motor & belt? As for the pulley material, I suspect that your controller / sensor system will obviate the need for worrying about any speed deviation caused by relatively inconsequential thermal expansion coefficients resulting from dissimilarity of materials between platter & pulley. I'd say your thought of choosing a material for light weight & wear index makes sense, especially if it looks nice. How about Titanium? any possibilities there? Igor --- Manfred Huber wrote: > Chris, > > >As before any ideas are > >welcome but lets try to work toward finalizing a > design. > > As has been pointed out before, a convex shape and > small flanges on both > ends are good ideas. The flanges are a great help > during the adjustment of > the belt tension. > > The notch (right word?) for the string should be V > shaped with a small flat > floor \_/ and not round IMHO. This provides better > friction. > > >For the pulley material I am thinking aluminum or > acrylic. > > My pulley is made from high grade hard aluminium > like the stuff used > in airplane construction. There is much belt > slipping during the acceleration > phase and you need to use a hard material for the > pulley or else it will wear > and loose it's perfectly round shape. A kind of > magnesium alloy may mee a good > idea (?) and it sure looks sexy. > > Regards > Manfred > > > ------------------ > Manfred Huber > MHuber@t-online.de > ------------------ > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: Re: [teres] Motor & Controller Date: Sun, 27 Feb 2000 11:58:38 -0700 From: Manfred Huber, Manfred Huber To: teres@aiko.com Igor, >Perhaps we should adopt a policy of automatically >giving the platter a helping hand on startup to avoid >the wear you mention, as well as the stress that would >affect everything including the motor & belt? As I have mentioned before you can start the motor by manually accelerating the platter. This is not only a very convenient feature but it also avoids slipping of the belt during power up. I use my aluminium pulley with 1/4" magnetic tape for about one year now and there is no sign of wear both on the belt and the pulley. >As for the pulley material, I suspect that your >controller / sensor system will obviate the need for >worrying about any speed deviation caused by >relatively inconsequential thermal expansion >coefficients resulting from dissimilarity of materials >between platter & pulley. You are right, there is no reason to worry about this. >I'd say your thought of choosing a material for light >weight & wear index makes sense, especially if it looks nice. >How about Titanium? any possibilities there? Titanium would indeed be very nice, but I expect it to be very costly, especially if you want to experiment with different pulleys. Regards Manfred ------------------ Manfred Huber MHuber@t-online.de ------------------ Subject: Re: [teres] Motor & Controller Date: Sun, 27 Feb 2000 13:52:02 -0700 From: Thom Mackris / Joan Panzella, Thom Mackris / Joan Panzella To: teres@aiko.com I've been "jump starting" my turntables, giving my platter a helping hand since I purchased my Linn in 1984. It becomes automatic very quickly. Thom ----- Original Message ----- From: Igor Kuznetsoff To: Sent: Sunday, February 27, 2000 10:02 AM Subject: Re: [teres] Motor & Controller Practical thoughts, Manfred. Perhaps we should adopt a policy of automatically giving the platter a helping hand on startup to avoid the wear you mention, as well as the stress that would affect everything including the motor & belt? As for the pulley material, I suspect that your controller / sensor system will obviate the need for worrying about any speed deviation caused by relatively inconsequential thermal expansion coefficients resulting from dissimilarity of materials between platter & pulley. I'd say your thought of choosing a material for light weight & wear index makes sense, especially if it looks nice. How about Titanium? any possibilities there? Igor --- Manfred Huber wrote: > Chris, > > >As before any ideas are > >welcome but lets try to work toward finalizing a > design. > > As has been pointed out before, a convex shape and > small flanges on both > ends are good ideas. The flanges are a great help > during the adjustment of > the belt tension. > > The notch (right word?) for the string should be V > shaped with a small flat > floor \_/ and not round IMHO. This provides better > friction. > > >For the pulley material I am thinking aluminum or > acrylic. > > My pulley is made from high grade hard aluminium > like the stuff used > in airplane construction. There is much belt > slipping during the acceleration > phase and you need to use a hard material for the > pulley or else it will wear > and loose it's perfectly round shape. A kind of > magnesium alloy may mee a good > idea (?) and it sure looks sexy. > > Regards > Manfred > > > ------------------ > Manfred Huber > MHuber@t-online.de > ------------------ > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com Subject: RE: [teres] Motor & Controller Date: Sun, 27 Feb 2000 14:05:56 -0700 From: Jon Lane, Jon Lane To: teres@aiko.com > I've been "jump starting" my turntables, giving > my platter a helping hand > since I purchased my Linn in 1984. It becomes > automatic very quickly. > > Thom On very cold mornings I use jumper cables on my Linn... ;o) Jon Lane Subject: Re: [teres] Motor & Controller Date: Sun, 27 Feb 2000 19:31:38 -0700 From: MaughanAudio@aol.com, MaughanAudio@aol.com To: teres@aiko.com Disregard prior note on convex shape. Seems you all have everything in hand. I guess I should read all mail before commenting. It is obvious that we have a very talented team. However I'm surprised no discussion occurred regarding the bearing mount/platform as I described. Subject: Re: [teres] Motor & Controller Date: Sun, 27 Feb 2000 19:42:55 -0700 From: MaughanAudio@aol.com, MaughanAudio@aol.com To: teres@aiko.com I like the ideas of titanium, magnesium, or even anodized aluminum. I guess it's a matter of what can be made at what cost? I do think that the important thing over mass considerations is life expectancy of the pulley. Subject: Re: [teres] Motor & Controller Date: Sun, 27 Feb 2000 19:47:05 -0700 From: MaughanAudio@aol.com, MaughanAudio@aol.com To: teres@aiko.com Jump starting is the only way to go, but then I still like stick shifts too. Subject: Re: [teres] Motor & Controller Date: Sun, 27 Feb 2000 23:23:10 -0700 From: Igor Kuznetsoff, Igor Kuznetsoff To: teres@aiko.com Well, excu-u-u-u-se me! I guess I'm spoiled. That "cheap ol' Dual's" DC/quartz PLL controlled P.S. supplies extra torque on startup (still not very fast, they knew to use low torque), tells you when the speed is stabilized, and the flat rubber belt doesn't slip. Maybe I should grease the belt, so I can practice up! :-) Igor --- Thom Mackris / Joan Panzella wrote: > I've been "jump starting" my turntables, giving my > platter a helping hand > since I purchased my Linn in 1984. It becomes > automatic very quickly. > > Thom > > ----- Original Message ----- > From: Igor Kuznetsoff > To: > Sent: Sunday, February 27, 2000 10:02 AM > Subject: Re: [teres] Motor & Controller > > > Practical thoughts, Manfred. > > Perhaps we should adopt a policy of automatically > giving the platter a helping hand on startup to > avoid > the wear you mention, as well as the stress that > would > affect everything including the motor & belt? > > As for the pulley material, I suspect that your > controller / sensor system will obviate the need for > worrying about any speed deviation caused by > relatively inconsequential thermal expansion > coefficients resulting from dissimilarity of > materials > between platter & pulley. I'd say your thought of > choosing a material for light weight & wear index > makes sense, especially if it looks nice. How about > Titanium? any possibilities there? > > Igor > > --- Manfred Huber wrote: > > Chris, > > > > >As before any ideas are > > >welcome but lets try to work toward finalizing a > > design. > > > > As has been pointed out before, a convex shape and > > small flanges on both > > ends are good ideas. The flanges are a great help > > during the adjustment of > > the belt tension. > > > > The notch (right word?) for the string should be V > > shaped with a small flat > > floor \_/ and not round IMHO. This provides better > > friction. > > > > >For the pulley material I am thinking aluminum or > > acrylic. > > > > My pulley is made from high grade hard aluminium > > like the stuff used > > in airplane construction. There is much belt > > slipping during the acceleration > > phase and you need to use a hard material for the > > pulley or else it will wear > > and loose it's perfectly round shape. A kind of > > magnesium alloy may mee a good > > idea (?) and it sure looks sexy. > > > > Regards > > Manfred > > > > > > ------------------ > > Manfred Huber > > MHuber@t-online.de > > ------------------ > > > > > > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com > > > __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com