UHMW
Hi,
Ok...up to date now.
Basically polyethylene then.Ineresting material...too bad we don't now its' mechanical impedance though.
You could use it as a top platter but expect a mild sonic signature.
Not as hard as it seems really,with a bit of imagination you can figure out ways...I hate to do all the thinking.
Hi,
Ok...up to date now.
Basically polyethylene then.Ineresting material...too bad we don't now its' mechanical impedance though.
You could use it as a top platter but expect a mild sonic signature.
Not as hard as it seems really,with a bit of imagination you can figure out ways...I hate to do all the thinking.
NOT THAT NEW
Hello,
The first Nottingham Analogue Mentor is more than 17 years old ...one of the first arrived in Belgium on September 1982.
At that time we (Tom and myself) didn't feel the "market" was ready for it.
I was though.
The point is...think beyond commercial designs and be ahead of them.
Actually the cones idea is just descriptive language,don't glue but mass load the parts...try to think of minimal interruption in the energy paths.
Cheers,
Hello,
The first Nottingham Analogue Mentor is more than 17 years old ...one of the first arrived in Belgium on September 1982.
At that time we (Tom and myself) didn't feel the "market" was ready for it.
I was though.
The point is...think beyond commercial designs and be ahead of them.
Actually the cones idea is just descriptive language,don't glue but mass load the parts...try to think of minimal interruption in the energy paths.
Cheers,
Since I've been a machinist for the past 26 years I think I understand your concept.
My post regarding controlling parallism and concentricty is very important to keep the assembly balanced, I think you'll agree. With my equipment I can do what you propose, just not sure that is the route I will take at the moment. I'd like to keep things fairly simple for the first run, if that's possible.
TO fdegrove and VinylAddict re platter composition
So a question to you two:
Are you saying that the redpoint type platter ,i.e., ~2 1/2" of aluminum, filled with a series of lead shot filled holes and topped by a screwed on plate of ~ 1/2" or 1" teflon or PVC is a bad idea or just not optimal in regard to being ahead of the curve?
Fdegrove, what materials do you recommend?
Mike
So a question to you two:
Are you saying that the redpoint type platter ,i.e., ~2 1/2" of aluminum, filled with a series of lead shot filled holes and topped by a screwed on plate of ~ 1/2" or 1" teflon or PVC is a bad idea or just not optimal in regard to being ahead of the curve?
Fdegrove, what materials do you recommend?
Mike
PLATTER MATTERS
Hello,
This platter would be my first choice if only it did not have one major flaw.At least to me that is.
Looking at the top you can spot the holes all over...now if you put a record on top the stylus will meet different mechanical impedances as it travels over the PVC and damping inserts.
Thisv is audible as the tonal colours will change.
Not a good idea IMO.They should have left the top a monolithic solid surface and put the damping on the bottom.
Other than that I have no quibbles with it.
Cheers,
Hello,
This platter would be my first choice if only it did not have one major flaw.At least to me that is.
Looking at the top you can spot the holes all over...now if you put a record on top the stylus will meet different mechanical impedances as it travels over the PVC and damping inserts.
Thisv is audible as the tonal colours will change.
Not a good idea IMO.They should have left the top a monolithic solid surface and put the damping on the bottom.
Other than that I have no quibbles with it.
Cheers,
PLATTER MATTERS
Thanks Frank - I wondered about the plethora of holes myself - however, something can be said for ease of manufacture.
How would one plug holes filled with shot and oil from the bottom? I considered this and have wondered how labor intensive it would be to make shallow, close tolerance, threaded plugs that could seal such holes from the top or from the bottom ?
Mike
Thanks Frank - I wondered about the plethora of holes myself - however, something can be said for ease of manufacture.
How would one plug holes filled with shot and oil from the bottom? I considered this and have wondered how labor intensive it would be to make shallow, close tolerance, threaded plugs that could seal such holes from the top or from the bottom ?
Mike
One groovy platter~!
I can explain how that can be layered. THis is something I may be doing to build my platter.
Bottom layer: 2" thick Aluminum drilled from underneath to be screwed into the top layer. Recessed or course to that the screw heads are not hanging out. I thought I might "stick" a dot of damping sheet over the screw heads. The machinist will machine 2" to 3" in diameter 1.5" deep holes into the TOP of the Aluminum platter. Fill these holes with minerial oil coated leadshot.
Top Layer: Solid 1" thick Black or White PVC (what is lamenated?)
with drilled inserts underneath to except the bolt threads from the bottom layer. I would say 1/2" deep.
Disclaimer: I am not a machinist or mechanical engineer. I just play one on TV and diyaudo forums. lol
I have to say, I wish PVC could be obtained in black or white over 1". It would be MUCH cheaper if the Aluminum layer was 1" and the PVC was 2". grrrr. Of course if you "liked" that grey color...
I personally didn't like the idea of screw head holes in the top of a platter either. Especially for $1100. *gulp*
Also, I personally don't feel that a 2" thick aluminum layer at 28.5 lbs, $218 delivered, needs to be further damped. But maybe it does. The 1" thick PVC layer is 7.5 lbs, $20. That gives us a total of 36lbs. Add another 10lbs of leadshot and you will be at almost 50lbs.
Which leads me to another question. Which aluminum grade should be used? 2024, 6061, 5052? I can't find any information so far that will tell me which is best suited for anti-resonance.
I can explain how that can be layered. THis is something I may be doing to build my platter.
Bottom layer: 2" thick Aluminum drilled from underneath to be screwed into the top layer. Recessed or course to that the screw heads are not hanging out. I thought I might "stick" a dot of damping sheet over the screw heads. The machinist will machine 2" to 3" in diameter 1.5" deep holes into the TOP of the Aluminum platter. Fill these holes with minerial oil coated leadshot.
Top Layer: Solid 1" thick Black or White PVC (what is lamenated?)
with drilled inserts underneath to except the bolt threads from the bottom layer. I would say 1/2" deep.
Disclaimer: I am not a machinist or mechanical engineer. I just play one on TV and diyaudo forums. lol
I have to say, I wish PVC could be obtained in black or white over 1". It would be MUCH cheaper if the Aluminum layer was 1" and the PVC was 2". grrrr. Of course if you "liked" that grey color...
I personally didn't like the idea of screw head holes in the top of a platter either. Especially for $1100. *gulp*
Also, I personally don't feel that a 2" thick aluminum layer at 28.5 lbs, $218 delivered, needs to be further damped. But maybe it does. The 1" thick PVC layer is 7.5 lbs, $20. That gives us a total of 36lbs. Add another 10lbs of leadshot and you will be at almost 50lbs.
Which leads me to another question. Which aluminum grade should be used? 2024, 6061, 5052? I can't find any information so far that will tell me which is best suited for anti-resonance.
Platter details
2024-Copper is the primary alloying element. It is quite expensive compared to 6061.
6061-Contains Silicon and Magnesium. Most everything I manufacture here in the Silicon Valley is made from this alloy.
5052-Contains Magnesium and Manganese as a hardener. You see this alloy used a lot in thin gauge form which is bent or formed. It is a maleable material.
6061-T6 would be my choice simply because it so common and inexpensive compared to the other choices.
It would be a monumental tedious task to use threaded plugs and they would leak if you did'nt use "O-Rings" to prevent leakage.
The alternative route to take would be to do the same as Redpoint except ream all of the bolt holes and make press-fit plugs out of PVC and press them in to fill the holes. After that put the platter assembly back on the lathe and cut the top surface and you'd have a hard time seeing any of the plugs. I've repaired expensive parts over the years using this method and it works very well.
The downside to this method is that you cannot disassemble the platter.
2024-Copper is the primary alloying element. It is quite expensive compared to 6061.
6061-Contains Silicon and Magnesium. Most everything I manufacture here in the Silicon Valley is made from this alloy.
5052-Contains Magnesium and Manganese as a hardener. You see this alloy used a lot in thin gauge form which is bent or formed. It is a maleable material.
6061-T6 would be my choice simply because it so common and inexpensive compared to the other choices.
It would be a monumental tedious task to use threaded plugs and they would leak if you did'nt use "O-Rings" to prevent leakage.
The alternative route to take would be to do the same as Redpoint except ream all of the bolt holes and make press-fit plugs out of PVC and press them in to fill the holes. After that put the platter assembly back on the lathe and cut the top surface and you'd have a hard time seeing any of the plugs. I've repaired expensive parts over the years using this method and it works very well.
The downside to this method is that you cannot disassemble the platter.
Dynamic Balancing
I'm still looking into this subject since I believe it is very important if the end result is a 40+lb composite platter. Check out this link, it describes the process. I'm trying to find someone locally to find out cost.
http://www.dynamicbalancing.co.uk/dynpage2.htm
I'm still looking into this subject since I believe it is very important if the end result is a 40+lb composite platter. Check out this link, it describes the process. I'm trying to find someone locally to find out cost.
http://www.dynamicbalancing.co.uk/dynpage2.htm
BALANCING
Hi,
While this has of course its' importance,one has to view this with respect to rotational speed.
It will hardly upset the TT if the platter has a slight unbalance at 33.33 RPM but at 78 RPM it will definitely show its' ugly face.
That is one more reason to work with solid material without all this extra damping in the first place.
Adding the leadshot etc. is bound to unbalance the platter.
For a DIY project I would steer clear from the extra damping...a well designed platter doesn't need it.
Just draw your on conclusions from it...and I said it before if needed it is better put at the rim of the platter then in it where it just upsets things.
My 2 cents,
Hi,
While this has of course its' importance,one has to view this with respect to rotational speed.
It will hardly upset the TT if the platter has a slight unbalance at 33.33 RPM but at 78 RPM it will definitely show its' ugly face.
That is one more reason to work with solid material without all this extra damping in the first place.
Adding the leadshot etc. is bound to unbalance the platter.
For a DIY project I would steer clear from the extra damping...a well designed platter doesn't need it.
Just draw your on conclusions from it...and I said it before if needed it is better put at the rim of the platter then in it where it just upsets things.
My 2 cents,
Re: BALANCING
I dont care much about dynamic balansing, because the bearing high is relatively small, comparing to the platter diameter. But static balansing can be made simply holding the bearing axle about 45 deg to horizon when filling with leadshot and then fine-tuning after sealing the holes by drilliing out the metal from the lower surface.
I'm with you about no-go for CLD platter. The CLD essential element is a viscoelastic layer, which may compromise the platter stiffness in vertical plane. I just don't think Redpoint platter is the case. Quite opposite, they reported bolted conection superirity above glueing, IMHO because the glue layer is some sort of viscoelastic material.
Upper PVC plate simply placed on top of the metal one - you cannot provide flawless contact between the plates surfaces in the real world of DIY manufacturing. It is a pity, really, but you can minimize the strain, induced by bolts, using plenty of low torque bolts, evenly distributed.
I'm agreed about covering the bolt heads with the layer of PVC or plug inserts (good idea, Vinyl Addict, but not a press-fit, just glue) to produce consistent surface, sacrifiying the possibility of playing with layers, however...
Cheers,
Michael
Filling the platter with lead has its own importance, besides of damping, distributing the mass close to the platter rim and adding rotation inertia to the platter - helps speed stabilizing consiberably. BTW, Walker platter is made of solid lead...fdegrove said:
I dont care much about dynamic balansing, because the bearing high is relatively small, comparing to the platter diameter. But static balansing can be made simply holding the bearing axle about 45 deg to horizon when filling with leadshot and then fine-tuning after sealing the holes by drilliing out the metal from the lower surface.
I'm with you about no-go for CLD platter. The CLD essential element is a viscoelastic layer, which may compromise the platter stiffness in vertical plane. I just don't think Redpoint platter is the case. Quite opposite, they reported bolted conection superirity above glueing, IMHO because the glue layer is some sort of viscoelastic material.
Upper PVC plate simply placed on top of the metal one - you cannot provide flawless contact between the plates surfaces in the real world of DIY manufacturing. It is a pity, really, but you can minimize the strain, induced by bolts, using plenty of low torque bolts, evenly distributed.
I'm agreed about covering the bolt heads with the layer of PVC or plug inserts (good idea, Vinyl Addict, but not a press-fit, just glue) to produce consistent surface, sacrifiying the possibility of playing with layers, however...
Cheers,
Michael
Arm board or arm pillar
I noticed that even high end turntables forgo the use of an arm pillar. Could that be because of conveniance and setup? Much easier to build and setup a turntable if the armboard is attached to the plynth. Is there any relivent reason for doing so? Maybe an armboard is sturdier and rigid is its part of a massive plynth? I can see why RedPoint and Kuzma built arm pillars. That further isolates the tonearm from the rumbling motor and turning platter. But at what sacrifice. If I were to use an arm pillar it couldn't be larger than 4 1/2" in diameter with a 9" long tonearm.
I suppose I do not need to use PVC for the plynth. Just the platter. I might just as well build my plynth out of some very heavy exotic wood with a bottom layer of 1" thick Aluminum. My machinist doesn't want to work more than a few layers for me.
I noticed that even high end turntables forgo the use of an arm pillar. Could that be because of conveniance and setup? Much easier to build and setup a turntable if the armboard is attached to the plynth. Is there any relivent reason for doing so? Maybe an armboard is sturdier and rigid is its part of a massive plynth? I can see why RedPoint and Kuzma built arm pillars. That further isolates the tonearm from the rumbling motor and turning platter. But at what sacrifice. If I were to use an arm pillar it couldn't be larger than 4 1/2" in diameter with a 9" long tonearm.
I suppose I do not need to use PVC for the plynth. Just the platter. I might just as well build my plynth out of some very heavy exotic wood with a bottom layer of 1" thick Aluminum. My machinist doesn't want to work more than a few layers for me.
PLATTER MATTERS
Hi,
Nothing indicates that :
1/One needs to bond the two layer in any way,the only thing you need is a way for the top layer to rest solidly on the bottom one.
It does not need to make contct over the full surface area...in fact it better not.
See my split platter remark before.
2/You can mimimize strain but then the effect is lost.
Cheers,
Hi,
Nothing indicates that :
1/One needs to bond the two layer in any way,the only thing you need is a way for the top layer to rest solidly on the bottom one.
It does not need to make contct over the full surface area...in fact it better not.
See my split platter remark before.
2/You can mimimize strain but then the effect is lost.
Cheers,
PILLAR OF SALT.
Hi,
Manufacturing costs seems more likely.
I find it very convenient to have a pillar so you can adjust overhang etc. by shifting its' position.
No,of course not.
If you can find aged wood that would do fine.
Make it thick and heavy,you can have it lacquered to further dampen it.
I would advise against the bottom layer of alu though.
Wood is a "live" material and will work against the metal fixtures.
Cheers,
Hi,
Manufacturing costs seems more likely.
I find it very convenient to have a pillar so you can adjust overhang etc. by shifting its' position.
No,of course not.
If you can find aged wood that would do fine.
Make it thick and heavy,you can have it lacquered to further dampen it.
I would advise against the bottom layer of alu though.
Wood is a "live" material and will work against the metal fixtures.
Cheers,
Leadshot filled wood?
Teres loads their plynths with leadshot. I assume they just drill large holes underneath and plug them closed with brass plates. I'm not sure how they exactly do this. I would rather use Aluminum-Acrylic-Aluminum sandwich but my machinist doesn't want to do all that work.
I've read a few posts on madison sound forum about organic properties of materials matching well with analog. They were discussing differant woods and MDF types for speaker cabinets. Then they mentioned that the sonic effects of sound refractions/reflections of the sealants can change the sound of a speaker. Basically they came down to that Shellac was one of the best choices. Especially over all that Poly-stuff. My woodworking book i just purchased and read (Im going to build my own speakers too) says that the best and old fashion way to apply Shellac is to rub it in with a towel in a figure 8 motion vigerously. Wait 30 minutes then do it again. Do it 5 times each day for 3 days in a row. Alot of elbow grease! But you will get unparrallel quality.
If I were to use some ultra dense heavy wood that how I would seal it.
fdegrove you stated that wood is a live material and woudl work against metal. What about brass or aluminum cones under a wood plynth? Isn't that the same concept?
Teres loads their plynths with leadshot. I assume they just drill large holes underneath and plug them closed with brass plates. I'm not sure how they exactly do this. I would rather use Aluminum-Acrylic-Aluminum sandwich but my machinist doesn't want to do all that work.
I've read a few posts on madison sound forum about organic properties of materials matching well with analog. They were discussing differant woods and MDF types for speaker cabinets. Then they mentioned that the sonic effects of sound refractions/reflections of the sealants can change the sound of a speaker. Basically they came down to that Shellac was one of the best choices. Especially over all that Poly-stuff. My woodworking book i just purchased and read (Im going to build my own speakers too) says that the best and old fashion way to apply Shellac is to rub it in with a towel in a figure 8 motion vigerously. Wait 30 minutes then do it again. Do it 5 times each day for 3 days in a row. Alot of elbow grease! But you will get unparrallel quality.
If I were to use some ultra dense heavy wood that how I would seal it.
fdegrove you stated that wood is a live material and woudl work against metal. What about brass or aluminum cones under a wood plynth? Isn't that the same concept?
SAME,SAME DIFFERENT.
Hi,
The cones aren't really solidly fixed under the plint,so this allows from some mirco movement that would not upset the whole.
Then of course there are all kinds of woods too.
I remember Tom Fletcher stressing the importance of aged (25 years +) woods for his top range TTs.
With a total TT weight of well over 100 lbs you can well imagine that you don't want the plinth to bend because its' weight at the support side is unevenly distributed.
Cheers,
Hi,
The cones aren't really solidly fixed under the plint,so this allows from some mirco movement that would not upset the whole.
Then of course there are all kinds of woods too.
I remember Tom Fletcher stressing the importance of aged (25 years +) woods for his top range TTs.
With a total TT weight of well over 100 lbs you can well imagine that you don't want the plinth to bend because its' weight at the support side is unevenly distributed.
Cheers,
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