Brass inserts
Maybe brass anchors. These anchors and bolts would have to be exactly the same weight. Tight tolerances. Non-magnetic and prestressed. Is that sold anywhere? Another machinist also stated that there maybe more balance problems the more complicated the platter gets. wonder if this is something I should forget about.
Another AA member was thinking of using Delrin instead of PVC for the top layer. Can anyone describe the differances of those two materials?
fdegrove, you say you don't like the idea of contraint layer damping. Have a better salution than that? I know VPI's $3000 to $10,000 turntables use prestressed non-magnetic screws to secure their sandwiched layers. I would rather stay away from too many screws because my machinist is a lazy sob hehe
Maybe brass anchors. These anchors and bolts would have to be exactly the same weight. Tight tolerances. Non-magnetic and prestressed. Is that sold anywhere? Another machinist also stated that there maybe more balance problems the more complicated the platter gets. wonder if this is something I should forget about.
Another AA member was thinking of using Delrin instead of PVC for the top layer. Can anyone describe the differances of those two materials?
fdegrove, you say you don't like the idea of contraint layer damping. Have a better salution than that? I know VPI's $3000 to $10,000 turntables use prestressed non-magnetic screws to secure their sandwiched layers. I would rather stay away from too many screws because my machinist is a lazy sob hehe
CLD
Hi,
Not on a revolving high precision instrument like a TT platter.
You could use different materials in different layers but there is no need to constrain them.
The idea of the split platter is useful for example if you want to use say a top PVC platter for excellent impedance matching with regard to the record.
The bottom platter can be a heavy metal machined platter and bearing assembly.
The two should only be slightly coupled in order to avoid interference between them.
Ideally they should be decoupled from one another.
Delrin is a much denser (harder) polymer than PVC.
PVC is by far the better material for the record platter interface.
Cheers,
Hi,
Not on a revolving high precision instrument like a TT platter.
You could use different materials in different layers but there is no need to constrain them.
The idea of the split platter is useful for example if you want to use say a top PVC platter for excellent impedance matching with regard to the record.
The bottom platter can be a heavy metal machined platter and bearing assembly.
The two should only be slightly coupled in order to avoid interference between them.
Ideally they should be decoupled from one another.
Delrin is a much denser (harder) polymer than PVC.
PVC is by far the better material for the record platter interface.
Cheers,
NottingHam platters
I see what your saying fdegroove. I had a NottingHam interspace with Hyperspace platter. The thing was a monster. Really nice turrntable. Its a close call weither to buy another one or build the Teres turntable concept. The Hyperspace platter was 4" thick. The top 1/2" layer was free floating from the rest of the platter. Made of a woven carbon graphite. The differance I see frrom that Interspace and the Teres is Inverted bearings, Teres has a separated motor, Teres plynth is heavier.
NottingHam plynth is some sort of MDF countertop matieral coated that looks like green marble. Very quite motor but is still part of the plynth. I've read that the Maxxon is a high quality motor used in the Space Shuttle. So I'm led to beleive that is one of the best motors for the money I can get.
I have no doubt that the Hyperspace platter is a MUCH better sounding and performing platter than a solid 3" thick Acrylic platter. Thats why I'm looking at a sandwiched platter like the VPI and Kuzma turntables. I only wish I could just buy a Hyperspace Platter and use the Teres bearing in that! lol
Sure would make this project easier
I see what your saying fdegroove. I had a NottingHam interspace with Hyperspace platter. The thing was a monster. Really nice turrntable. Its a close call weither to buy another one or build the Teres turntable concept. The Hyperspace platter was 4" thick. The top 1/2" layer was free floating from the rest of the platter. Made of a woven carbon graphite. The differance I see frrom that Interspace and the Teres is Inverted bearings, Teres has a separated motor, Teres plynth is heavier.
NottingHam plynth is some sort of MDF countertop matieral coated that looks like green marble. Very quite motor but is still part of the plynth. I've read that the Maxxon is a high quality motor used in the Space Shuttle. So I'm led to beleive that is one of the best motors for the money I can get.
I have no doubt that the Hyperspace platter is a MUCH better sounding and performing platter than a solid 3" thick Acrylic platter. Thats why I'm looking at a sandwiched platter like the VPI and Kuzma turntables. I only wish I could just buy a Hyperspace Platter and use the Teres bearing in that! lol
Sure would make this project easier
Hi everyone, this will be my 1st post.
I too am going to build a TT. I own a machine shop in the Silicon Valley and business has been slow lately so I decided to put my equipment to good use and build a TT.
I will be buying the motor only, everything else will be fabricated.
I have not yet decided on material(s) for the platter(I am contemplating using UHMV, anti-static plastic) but I will be using an inverted bearing design with absolute minimum friction the goal obviously.
I am looking at using a bearing housing with spindle bearing contact at the top and bottom 0.250" only. I will relieve the area in between to create an oil bath. This will also promote less friction between the housing and spindle bearing.
I will offer a little info on making it easier to calculate weights of materials.
Every material has a specific gravity. Since I am a Machinist I have the Machinist Handbook which contains that info, you can find it on the web I'm sure. There is a formula to calculate weights if you know the specific gravity of the material.
To give you an idea, Aluminum has a SG of 2.7, lead 11.342, Acrylic 1.18, Glass 2.6, Brass 8.6.
To find the weight per cubic foot of a material, the specific gravity of which is known, multiply the specific gravity by 62.355. There are other formulas available, search the web, I'm sure you can find them.
If you must use bolts then put them on the bottom of the platter,special inserts exist for softer materials wherein you can than screw bolts.
I too am going to build a TT. I own a machine shop in the Silicon Valley and business has been slow lately so I decided to put my equipment to good use and build a TT.
I will be buying the motor only, everything else will be fabricated.
I have not yet decided on material(s) for the platter(I am contemplating using UHMV, anti-static plastic) but I will be using an inverted bearing design with absolute minimum friction the goal obviously.
I am looking at using a bearing housing with spindle bearing contact at the top and bottom 0.250" only. I will relieve the area in between to create an oil bath. This will also promote less friction between the housing and spindle bearing.
I will offer a little info on making it easier to calculate weights of materials.
Every material has a specific gravity. Since I am a Machinist I have the Machinist Handbook which contains that info, you can find it on the web I'm sure. There is a formula to calculate weights if you know the specific gravity of the material.
To give you an idea, Aluminum has a SG of 2.7, lead 11.342, Acrylic 1.18, Glass 2.6, Brass 8.6.
To find the weight per cubic foot of a material, the specific gravity of which is known, multiply the specific gravity by 62.355. There are other formulas available, search the web, I'm sure you can find them.
If you must use bolts then put them on the bottom of the platter,special inserts exist for softer materials wherein you can than screw bolts.
I would recommend using helicoils or locking helicoils, they are very lightweight and strong.
Hi, all
Mike, this is AutoCAD drawing, as you guess. No problem, just e-mail me if you are interested, so I can attach hevier file than the forum post allowes.
StylinLP, there are two reasons behind 60 bolts use:1) even distribution of stress induced by the bolts head into the rather compliant plastic and 2) firm contact between layers at every point of the platter surface without to much torque. Agreed with your proposal of glueing the layers to hide the bolts head. The bonding should be flawless, not compromising vibrations transfer. Again, acrylic seems better from this point, using dychlorethane, which is “melting”the plastic surfaces. Actually, hiding the bolts is a matter of taste: for me, polyshed sunken heads with allen key holes give the platter “industrial” look. (BTW, fancy Teres lead platter reminds me merry-go-round stuffed with open caviar cans).
Open bolts also allow you further experimentation with different layers. Bronze inserts would we fine, if you can find them at reasonable cost.
Fdegrove, do you have reasons not to trust to Redpoint reports about superior quality of sandwiched platter? From the DIY feasibility point of view, I see no other Hi-end league platter design, allowing DIY/machine shop embodiment at part of ready made platter price. I’ve placed my order for the aluminium disc at about 300$, the rest I hope to complete by myself.
What do you exactly mean by “consraint layer” design? IMHO, the platter should:1) have matched mechanical impedance with LP, in order to be “transparent” for the record/stylus induced vibrations, transfer them to the subplatter and absorb vibrations, and not to reject them to the stylus; 2) provide very stable, non compliant surface for the record. Both of two requirement are met with laminated platter design.
You are absolutely right regarding record spindle separated from bearing. I will glue it in the upper layer hole.
Cheers,
Michael
Mike, this is AutoCAD drawing, as you guess. No problem, just e-mail me if you are interested, so I can attach hevier file than the forum post allowes.
StylinLP, there are two reasons behind 60 bolts use:1) even distribution of stress induced by the bolts head into the rather compliant plastic and 2) firm contact between layers at every point of the platter surface without to much torque. Agreed with your proposal of glueing the layers to hide the bolts head. The bonding should be flawless, not compromising vibrations transfer. Again, acrylic seems better from this point, using dychlorethane, which is “melting”the plastic surfaces. Actually, hiding the bolts is a matter of taste: for me, polyshed sunken heads with allen key holes give the platter “industrial” look. (BTW, fancy Teres lead platter reminds me merry-go-round stuffed with open caviar cans).
Open bolts also allow you further experimentation with different layers. Bronze inserts would we fine, if you can find them at reasonable cost.Fdegrove, do you have reasons not to trust to Redpoint reports about superior quality of sandwiched platter? From the DIY feasibility point of view, I see no other Hi-end league platter design, allowing DIY/machine shop embodiment at part of ready made platter price. I’ve placed my order for the aluminium disc at about 300$, the rest I hope to complete by myself.
What do you exactly mean by “consraint layer” design? IMHO, the platter should:1) have matched mechanical impedance with LP, in order to be “transparent” for the record/stylus induced vibrations, transfer them to the subplatter and absorb vibrations, and not to reject them to the stylus; 2) provide very stable, non compliant surface for the record. Both of two requirement are met with laminated platter design.
You are absolutely right regarding record spindle separated from bearing. I will glue it in the upper layer hole.
Cheers,
Michael
Glued
Hmm..lots of food for thought!@
Hi Vinyl-Addict! Welcome to the diyaudio analogue forum! Your exp as a machinist I'm sure will be helpfull here.
So gluing with special dychlorethane would melt the layers together but would forgo any changed in platter design later since this will seal the bolts. This all at an additional cost.
I suppose then just bolting from the underside using helicoils or locking helicoils is another alternative. This way I wouldnt have to buy another PVC layer and have that machined. 2" aluminum is twice as costly as 1" aluminum...PVC only comes in ugly grey when you get over 1" thick. So far from what I've heard PVC is the closest material to what Vinyl records are made of. I really don't think using any plastic would be an answer to the energy coupling mated to a vinyl record. I read an article explaining in detail why Acrylic is not the best choice as a layer that a vinyl record should be pressed up against. Acrylic is just another plastic. Just like Delrin? (I just got lost about Delrin) Also just like UHMV. Those are both Plastic materials right? I've been told that PVC is the closest of all material to what Vinyl records are made of. Its totally confusing. I tried looking up numerous materials on the web. There must be thousands of variations of everything.
Another benefit of having Brass or locking helicoils is extra weight. I think that trying to achive at least 40lbs weight in a platter is ideal. RedPoint told me that their bearings are specced to work up to 60lbs. I wonder what the Teres bearing is.
Vinyl-Addict. Basically your bearing is going to be the same as Teres except much more beefier? Have you read all the litiature how their bearing was designed? RedPoint did take that basic design and beefed it up. One of the things they mentioned was that it had a larger oil sump. If you show that the bearing your planning on machining is a better version of the Teres maybe you can make a few more while your at it and sell us one
Hmm..lots of food for thought!@
Hi Vinyl-Addict! Welcome to the diyaudio analogue forum! Your exp as a machinist I'm sure will be helpfull here.
So gluing with special dychlorethane would melt the layers together but would forgo any changed in platter design later since this will seal the bolts. This all at an additional cost.
I suppose then just bolting from the underside using helicoils or locking helicoils is another alternative. This way I wouldnt have to buy another PVC layer and have that machined. 2" aluminum is twice as costly as 1" aluminum...PVC only comes in ugly grey when you get over 1" thick. So far from what I've heard PVC is the closest material to what Vinyl records are made of. I really don't think using any plastic would be an answer to the energy coupling mated to a vinyl record. I read an article explaining in detail why Acrylic is not the best choice as a layer that a vinyl record should be pressed up against. Acrylic is just another plastic. Just like Delrin? (I just got lost about Delrin) Also just like UHMV. Those are both Plastic materials right? I've been told that PVC is the closest of all material to what Vinyl records are made of. Its totally confusing. I tried looking up numerous materials on the web. There must be thousands of variations of everything.
Another benefit of having Brass or locking helicoils is extra weight. I think that trying to achive at least 40lbs weight in a platter is ideal. RedPoint told me that their bearings are specced to work up to 60lbs. I wonder what the Teres bearing is.
Vinyl-Addict. Basically your bearing is going to be the same as Teres except much more beefier? Have you read all the litiature how their bearing was designed? RedPoint did take that basic design and beefed it up. One of the things they mentioned was that it had a larger oil sump. If you show that the bearing your planning on machining is a better version of the Teres maybe you can make a few more while your at it and sell us one
My primary concern with incorporating brass or lead plugs into the platter would be an unbalanced assembly. If you are planning on having the platter balanced after all machining is performed, then go for it, otherwise you would have to have exact(and nothing is exact)weights located exactly equal distance from each other on the platter. I would look into balancing first.
An easier option to maintain balance would be to machine 2 separate platters and pin them precisely to control location, then bolt them together and finish all machining operations, then remove the pins if you like. I think that is a good option and not too hard to do for the machinist.
BTW, helicoils are very light but strong. Plugs are heavier and require more precise machining to allow for precise press fit into material, I recommend helicoils if you must use threaded inserts. You would need to figure out how many bolts to use, an analysis program would be helpful there. A mechanical designer friend of mine has such a program, we're trying to find time to sit down and create a good design to start fabrication. He also owns a disc cutting lathe and is very knowledgable in vinyl related issues. Finding time to design will be the hardest part of the process, buiding the TT will not be a problem.
CLD
Hi,
No,but then it is a commercial product for the DIY market.
You see when you use CLD you have to know what you're doing and you have to be tooled up for it.
I doubt many DIY designers are.
CLD, in a nutshell is applied damping by the use of different materials by putting it under stress.
The choice of materials and the amount of stress and where to apply it are all factors to make it work.
IMO you don't need that in a platter.
It would be effective in a plint however.
May I suggest you thread it so it can be screwed into the platter?
Excellent materials are POM,Delrin or carbon fibre rods.
Cheers,
Hi,
No,but then it is a commercial product for the DIY market.
You see when you use CLD you have to know what you're doing and you have to be tooled up for it.
I doubt many DIY designers are.
CLD, in a nutshell is applied damping by the use of different materials by putting it under stress.
The choice of materials and the amount of stress and where to apply it are all factors to make it work.
IMO you don't need that in a platter.
It would be effective in a plint however.
May I suggest you thread it so it can be screwed into the platter?
Excellent materials are POM,Delrin or carbon fibre rods.
Cheers,
Errr. retyping LONG post
Don't you hate when you accidently switchs webpages in the middle of posting, just to come back and see it gone. Sigh. Have to retype.
fedgrove you say that CLD is need for a plynth but not a platter. I don't see why. Its the platter that is spinning on a bearing. The record sits on the platter and the cartiridge is interacting with this moving mass. Isn't that whats important most of all for balance?
My machinist seems to think that there isn't going to be any problem with anything he machines. But then again I had to beat him over the head to boot his wood speaker stands and buy steel welded speaker stands. That his cartridge alignment is "good enough". But he did setup his LP12 with just an owners manual. heh
I'm confused how a machine shop balances a platter. Do they have a machine that shaves an object to balance it? Seems to me that they would have to wether its one layer or three.
Here is a quote from Michael Percy Audio of damping materials they sell. Just have to stick a sheet in logical places underneath the aluminum platter. Or even between the two layers?
DAMPING SHEETS, COMPOUNDS, MOUNTING HARDWARE
SORBOTHANE: Adhesive backed .1" thick 6" square sheets of Sorbothane which you can slice up and apply to tonearms, cartridge bodies, etc., especially effective in
constrained layer applications where it is sandwiched between other materials… $16.00 each
MICROSORB: A state of the art soft, compliant damping sheet material with a unique cellular construction formed from microscopic viscoelastic spheres which deform rather
than compress when loaded. The result is shock attenuating power unsurpassed by any other material I am familiar with. The material itself is naturally adhesive throughout and
therefore adheres on both sides, making it ideal for sandwiching with other materials for constrained layer damping. Used by itself, you will want to cover it with other damping
materials or a layer of some type (such as TI Shield) to prevent its sticky surface from attracting dirt. Cut in small pieces it is an effective adhesive for mounting small parts, with
the added benefit of superb damping, melting point exceeds 350°F, translucent and colorless, two thicknesses available:
1.5mm thickness, 12" x 24"/$16.50 12" x 12"/$8.50 3.0mm thickness, 12" x 24"/$21.00 12" x 12"/$11.00 5.0mm thickness, 12" x 24"/$34.00 12" x 12 "/$18.00
BLACK HOLE PAD II: 70 mil thick self adhesive black flexible viscoelastic sheet material with a black fine leather grain pebble finish designed for damping speaker cabinet
resonances, but useful to damp any type of audio equipment panel within its 50° to 100° F rating (meets UL 94 V-O flame resistance); attractive in appearance it may be used
externally as well as hidden inside components, several layers may be laminated for additional damping, excellent for constrained layer construction, speaker gaskets etc.,
approximately 12" x 27" sheets… $13.95 each
SOUNDCOAT Damping Compound: Non toxic water based emulsion vibration damping compound with maximum effectiveness between 10Hz and 20KHz, excellent for
speaker enclosures, concentrate is diluted (dilute with white latex paint) for application, product can be troweled, sprayed, brushed, or poured into enclosure for application,
request literature.… Quart/$15.00 Gallon/$54 East of the Rockies add $5/gallon can shipping, + standard $6.00 ship charge per order
EAR ISODAMP SD: Self-adhesive semi-rigid damping sheets from the industry leader in vibration, shock, and motion control. Maximum performance with minimum weight
and thickness, low memory, resists cracking in tightly angled spaces, meets UL 94V-O certification for flame resistance, brown color. The best material available for free air
damping of metal parts, circuit boards, and chassis covers and enclosures. Three variations of this material are available:
*SD40… .040" thick sheet, .37 pounds per square foot: 12" x 27"/$19.00 or 9" x 12"/$7.00 (Cut this up to make your own magic “dots” very inexpensively.)
*SD40AL… .040" thick w/ 5 mil aluminum constraining foil for increased damping and flame resistance: 12" x 27"/$30.00 or 9" x 12"/$11.50
*SD125… .125" thick sheet, 1.11 pounds per square foot: 12" x 27"/$37.00 or 9" x 12"/$13.00 or 9" x 6"/$7.00 (my first choice for damping metal chassis)
EAR TED: Economical self-adhesive .070" thick damping sheet material, low cost chassis damping, black… 12" x 40"/$11.50, 12" x 20"/$5.95, or 6" x 20"/$3.00 each
EAR TAD Damping Foils: Composite extensional damping sheet
consisting of viscoelastic pressure sensitive adhesive constrained by an aluminum foil layer, very light and
flexible for weight sensitive applications, the .005" thickness is excellent for damping tone arms, .005" x 9" x 12"/$2.95 each .010" x 9" x 12"/$4.50 each
EAR C-1002 ISODAMP: Compliant sheet material for high performance constrained layer damping, low rebound, excellent for making shock mounts, turntable and isolation
bases, available in a variety of thicknesses to accommodate any need, tough yet soft and flexible, blue color, adhesive back with MicroSorb if required.
.015"… 12" x 27"/$11.50, 12" x 13/$6.00 .030"… 12" x 27"/$12.95, 12" x 13"/$6.50 .062"… 12" x 27"/$14.95, 12" x 13"/$7.50
.125"… 12" x 27"/$26.50, 12" x 13"/$13.50 .250"… 12" x 27"/$54.50, 12" x 13"/$27.50, 12" x 6.5"/$14.00, 9" x 9.75"/$15.00, 6.5" x 6"/$7.50
Don't you hate when you accidently switchs webpages in the middle of posting, just to come back and see it gone. Sigh. Have to retype.
fedgrove you say that CLD is need for a plynth but not a platter. I don't see why. Its the platter that is spinning on a bearing. The record sits on the platter and the cartiridge is interacting with this moving mass. Isn't that whats important most of all for balance?
My machinist seems to think that there isn't going to be any problem with anything he machines. But then again I had to beat him over the head to boot his wood speaker stands and buy steel welded speaker stands. That his cartridge alignment is "good enough". But he did setup his LP12 with just an owners manual. heh
I'm confused how a machine shop balances a platter. Do they have a machine that shaves an object to balance it? Seems to me that they would have to wether its one layer or three.
Here is a quote from Michael Percy Audio of damping materials they sell. Just have to stick a sheet in logical places underneath the aluminum platter. Or even between the two layers?
DAMPING SHEETS, COMPOUNDS, MOUNTING HARDWARE
SORBOTHANE: Adhesive backed .1" thick 6" square sheets of Sorbothane which you can slice up and apply to tonearms, cartridge bodies, etc., especially effective in
constrained layer applications where it is sandwiched between other materials… $16.00 each
MICROSORB: A state of the art soft, compliant damping sheet material with a unique cellular construction formed from microscopic viscoelastic spheres which deform rather
than compress when loaded. The result is shock attenuating power unsurpassed by any other material I am familiar with. The material itself is naturally adhesive throughout and
therefore adheres on both sides, making it ideal for sandwiching with other materials for constrained layer damping. Used by itself, you will want to cover it with other damping
materials or a layer of some type (such as TI Shield) to prevent its sticky surface from attracting dirt. Cut in small pieces it is an effective adhesive for mounting small parts, with
the added benefit of superb damping, melting point exceeds 350°F, translucent and colorless, two thicknesses available:
1.5mm thickness, 12" x 24"/$16.50 12" x 12"/$8.50 3.0mm thickness, 12" x 24"/$21.00 12" x 12"/$11.00 5.0mm thickness, 12" x 24"/$34.00 12" x 12 "/$18.00
BLACK HOLE PAD II: 70 mil thick self adhesive black flexible viscoelastic sheet material with a black fine leather grain pebble finish designed for damping speaker cabinet
resonances, but useful to damp any type of audio equipment panel within its 50° to 100° F rating (meets UL 94 V-O flame resistance); attractive in appearance it may be used
externally as well as hidden inside components, several layers may be laminated for additional damping, excellent for constrained layer construction, speaker gaskets etc.,
approximately 12" x 27" sheets… $13.95 each
SOUNDCOAT Damping Compound: Non toxic water based emulsion vibration damping compound with maximum effectiveness between 10Hz and 20KHz, excellent for
speaker enclosures, concentrate is diluted (dilute with white latex paint) for application, product can be troweled, sprayed, brushed, or poured into enclosure for application,
request literature.… Quart/$15.00 Gallon/$54 East of the Rockies add $5/gallon can shipping, + standard $6.00 ship charge per order
EAR ISODAMP SD: Self-adhesive semi-rigid damping sheets from the industry leader in vibration, shock, and motion control. Maximum performance with minimum weight
and thickness, low memory, resists cracking in tightly angled spaces, meets UL 94V-O certification for flame resistance, brown color. The best material available for free air
damping of metal parts, circuit boards, and chassis covers and enclosures. Three variations of this material are available:
*SD40… .040" thick sheet, .37 pounds per square foot: 12" x 27"/$19.00 or 9" x 12"/$7.00 (Cut this up to make your own magic “dots” very inexpensively.)
*SD40AL… .040" thick w/ 5 mil aluminum constraining foil for increased damping and flame resistance: 12" x 27"/$30.00 or 9" x 12"/$11.50
*SD125… .125" thick sheet, 1.11 pounds per square foot: 12" x 27"/$37.00 or 9" x 12"/$13.00 or 9" x 6"/$7.00 (my first choice for damping metal chassis)
EAR TED: Economical self-adhesive .070" thick damping sheet material, low cost chassis damping, black… 12" x 40"/$11.50, 12" x 20"/$5.95, or 6" x 20"/$3.00 each
EAR TAD Damping Foils: Composite extensional damping sheet
consisting of viscoelastic pressure sensitive adhesive constrained by an aluminum foil layer, very light and
flexible for weight sensitive applications, the .005" thickness is excellent for damping tone arms, .005" x 9" x 12"/$2.95 each .010" x 9" x 12"/$4.50 each
EAR C-1002 ISODAMP: Compliant sheet material for high performance constrained layer damping, low rebound, excellent for making shock mounts, turntable and isolation
bases, available in a variety of thicknesses to accommodate any need, tough yet soft and flexible, blue color, adhesive back with MicroSorb if required.
.015"… 12" x 27"/$11.50, 12" x 13/$6.00 .030"… 12" x 27"/$12.95, 12" x 13"/$6.50 .062"… 12" x 27"/$14.95, 12" x 13"/$7.50
.125"… 12" x 27"/$26.50, 12" x 13"/$13.50 .250"… 12" x 27"/$54.50, 12" x 13"/$27.50, 12" x 6.5"/$14.00, 9" x 9.75"/$15.00, 6.5" x 6"/$7.50
CLD
Hi,
I never said you couldn't apply it for the platter,only advised against it.
Never said it was needed for the plinth either,I said it would more effective there to break up resonance.
I'll repeat: do not confuse the use of different materials in a platter with CLD.
I state it again: there is no point to apply CLD to a rotating mass,where vibrational evacution benefits most from a single monolithic mass that can be damped in various ways.
Imagine you use PVC for the top layer (a relatively soft material) what are you going to put underneath as a second layer?
A harder or softer material?
Cheers,
Hi,
I never said you couldn't apply it for the platter,only advised against it.
Never said it was needed for the plinth either,I said it would more effective there to break up resonance.
I'll repeat: do not confuse the use of different materials in a platter with CLD.
I state it again: there is no point to apply CLD to a rotating mass,where vibrational evacution benefits most from a single monolithic mass that can be damped in various ways.
Imagine you use PVC for the top layer (a relatively soft material) what are you going to put underneath as a second layer?
A harder or softer material?
Cheers,
Balancing
When I was an apprentice in the 70's we made centrifugal pumps and the impellers that were inside the pump had to be balanced. They used a machine to balance these impellers, however I did not use this machine myself so I can't say how they figured out where to remove the weight.
They would locate the areas out of balance and remove weight by drilling hole(s)to finetune the balance.
When I was an apprentice in the 70's we made centrifugal pumps and the impellers that were inside the pump had to be balanced. They used a machine to balance these impellers, however I did not use this machine myself so I can't say how they figured out where to remove the weight.
They would locate the areas out of balance and remove weight by drilling hole(s)to finetune the balance.
Contrain Layer Damping!
Oops. I got lost a second there. Thought you were talking about machine balancing. Well, NottingHam has a top layer thats not bolted or secured to the bottom layers. So I guess if thats good enough for them then its good enough for us...
Lets rehash "my" idea of the platter.
Bottom layer: 1" thick aluminum. Damped underneath with some sort of damping sheet and a glued on Oracle Strobe disk. (hey. that doublesided sticky damping sheets they sell)
Top layer: 2" thick (insert material here) drilled from underneath and plugged with screw inserts.
Alternative top layer on top of the two previous 1" thick layers: Glue melt another layer of 1" thick PVC to cover the screw head if platter is being screwed from above into the aluminum.
Or alternatively: 1" aluminum (bottom) 1" PVC (middle) 1" PVC (top). The bottom and middle are screwed together. The top layer is just resting on the bottom two layers. Just like NottingHam platters. Don't know it this is a good idea.
About PVC. From what I have read PVC is the closest impedance match to vinyl of any other materials available. If anyone knows what materials out there would be better I would really like to know what it is and why.
Oops. I got lost a second there. Thought you were talking about machine balancing. Well, NottingHam has a top layer thats not bolted or secured to the bottom layers. So I guess if thats good enough for them then its good enough for us...
Lets rehash "my" idea of the platter.
Bottom layer: 1" thick aluminum. Damped underneath with some sort of damping sheet and a glued on Oracle Strobe disk. (hey. that doublesided sticky damping sheets they sell)
Top layer: 2" thick (insert material here) drilled from underneath and plugged with screw inserts.
Alternative top layer on top of the two previous 1" thick layers: Glue melt another layer of 1" thick PVC to cover the screw head if platter is being screwed from above into the aluminum.
Or alternatively: 1" aluminum (bottom) 1" PVC (middle) 1" PVC (top). The bottom and middle are screwed together. The top layer is just resting on the bottom two layers. Just like NottingHam platters. Don't know it this is a good idea.
About PVC. From what I have read PVC is the closest impedance match to vinyl of any other materials available. If anyone knows what materials out there would be better I would really like to know what it is and why.
PROPORTIONS
Hi StylinLP,
If I may do some suggestions:
Make the Bottom layer 2" to 3" thick and don't damp it.
I wouldn't permanently fix a strobe either (it detracts).
Try to make it about 15 to 18 Kgs.
1" to 1.5" would be sufficient.Don't glue or screw it to the bottom layer.
Material:Any hard PVC,preferably black (UV resistant).
This is only partly true since many PVC polymers exist, it would provide a fine augmentation of mass for the vinyl record.
Choose a hard PVC, the softer ones are easily scratched.
If you choose this then don't use a mat on top.
The top can be made anti-static with a graphite coating.
Just some thoughts,
Hi StylinLP,
If I may do some suggestions:
Make the Bottom layer 2" to 3" thick and don't damp it.
I wouldn't permanently fix a strobe either (it detracts).
Try to make it about 15 to 18 Kgs.
1" to 1.5" would be sufficient.Don't glue or screw it to the bottom layer.
Material:Any hard PVC,preferably black (UV resistant).
This is only partly true since many PVC polymers exist, it would provide a fine augmentation of mass for the vinyl record.
Choose a hard PVC, the softer ones are easily scratched.
If you choose this then don't use a mat on top.
The top can be made anti-static with a graphite coating.
Just some thoughts,
Top layer
What do you think about using UHMW for the top layer, this is an anti-static material?($30 for a 1"thk x 12" sq)
How do you keep both layers together if you don't glue or screw? What's wrong with screwing them together?
I reworked a Simon Yorke Stainless platter recently and noticed it had a graphite like layer(1/8" thick)of material which was placed between the platter and record.
What do you think about using UHMW for the top layer, this is an anti-static material?($30 for a 1"thk x 12" sq)
How do you keep both layers together if you don't glue or screw? What's wrong with screwing them together?
I reworked a Simon Yorke Stainless platter recently and noticed it had a graphite like layer(1/8" thick)of material which was placed between the platter and record.
VINYL JUNKIES
Hi,
Nothing...what is it?
Mechanical impedance etc?
Weblink somewhere?
Use small cutouts+disks so it stays centered.Its' own weight will keep it seated.
If you want to decouple from the bottom platter (which is better still) use three tiny metal cones that fit in small indents (equal depth must be observed) on the bottom layer or something similar in a triangular position at the rim of your platter.
Tiny balls work fine as well but the tend to get lost in transport.
Just a spray job works already,we don't want to compromise on vertical compliance (they're shouldn't be any).
Cheers,
Hi,
Nothing...what is it?
Mechanical impedance etc?
Weblink somewhere?
Use small cutouts+disks so it stays centered.Its' own weight will keep it seated.
If you want to decouple from the bottom platter (which is better still) use three tiny metal cones that fit in small indents (equal depth must be observed) on the bottom layer or something similar in a triangular position at the rim of your platter.
Tiny balls work fine as well but the tend to get lost in transport.
Just a spray job works already,we don't want to compromise on vertical compliance (they're shouldn't be any).
Cheers,
Progressive thinking!
Wow. Thats one far out idea. Placing a 1" thick PVC platter onto of a 1" thick aluminum platter separated by 3 small high end cones! I realize they do make some very exotic high performace cones for around $80 /3. But I don't know if this is a sound idea. Not being a machinist or a mechanical engineer I can only guess how this idea would perform. How stable and rigid would this dual platter be? I know this concept is great for stereo racks but those are not moving. If the cones were glued to the bottom of the top platter and the tips set into a tight pin hole, maybe that would do it. That top 1" thick PVC platter is only 7.5 LBS. Why hasn't anyone thought of this before? There is ALOT of turntable companies out there these days. The most elabrate platter design i've seen is the GryoDek SE with its Brass Pucks set into the underside of the platter.
I looked up prices and weights of Brass platter 13" diameter.
.25" thick is $130 at 11 LBS
.5" thick is $225 at 22 LBS
1" thick is $350 at 41 LBS
(roughly)
Surprisingly thats the same weight AND price as Stainless Steel. hmmm. Aluminum is roughly half the weight and price.
Wow. Thats one far out idea. Placing a 1" thick PVC platter onto of a 1" thick aluminum platter separated by 3 small high end cones! I realize they do make some very exotic high performace cones for around $80 /3. But I don't know if this is a sound idea. Not being a machinist or a mechanical engineer I can only guess how this idea would perform. How stable and rigid would this dual platter be? I know this concept is great for stereo racks but those are not moving. If the cones were glued to the bottom of the top platter and the tips set into a tight pin hole, maybe that would do it. That top 1" thick PVC platter is only 7.5 LBS. Why hasn't anyone thought of this before? There is ALOT of turntable companies out there these days. The most elabrate platter design i've seen is the GryoDek SE with its Brass Pucks set into the underside of the platter.
I looked up prices and weights of Brass platter 13" diameter.
.25" thick is $130 at 11 LBS
.5" thick is $225 at 22 LBS
1" thick is $350 at 41 LBS
(roughly)
Surprisingly thats the same weight AND price as Stainless Steel. hmmm. Aluminum is roughly half the weight and price.
Here are UHMW links, I can't find the mechanical impedance spec. however.
http://www.aetnaplastics.com/ws-uhmw.htm
http://www.redwoodplastics.com/specsheets/uhmw.html
http://www.ultrapoly.com/Pages/pr_physprop.html
http://www.polymerplastics.com/mechanical_uhmw.shtml
http://www.aetnaplastics.com/ws-uhmw.htm
http://www.redwoodplastics.com/specsheets/uhmw.html
http://www.ultrapoly.com/Pages/pr_physprop.html
http://www.polymerplastics.com/mechanical_uhmw.shtml
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.