Looking for thought...
I have a DIY table with a motor using a brass pulley designed for a flat belt (aka: from an older Kenwood belt drive). I am running my DIY table with an audio cassette tape as a belt and it works well enough. This said I have another motor which came from either an audio cassette deck or VCR. It has a hard plastic-like pulley that is of a narrow groove design for running a thin round or v-belt. I was thinking of trying this on on the other motor shaft to run a silk thread drive for my turntable. I wonder if any of you here have thoughts on which material is better, a wider brass pulley for a flat belt or a thinner grooved plastic pulley for a round or V belt?
Next, I was able to easily pull the plastic pulley off the motor it came with. The brass pulley currently on the motor I'm using is on tighter and I am worried about any damage to the motor if I try to pry this off. Any ideas on doing this with little fear in damaging the motor or shaft?
I really am only considering this for the curiosity of it. I am just wondering if it will improve the performance of my setup or not? The drive diameter of both pullies looks very similar and as my motor is a D.C. servo I have trim pots for fine adjusting speed control.
Thanks in advance.
I have a DIY table with a motor using a brass pulley designed for a flat belt (aka: from an older Kenwood belt drive). I am running my DIY table with an audio cassette tape as a belt and it works well enough. This said I have another motor which came from either an audio cassette deck or VCR. It has a hard plastic-like pulley that is of a narrow groove design for running a thin round or v-belt. I was thinking of trying this on on the other motor shaft to run a silk thread drive for my turntable. I wonder if any of you here have thoughts on which material is better, a wider brass pulley for a flat belt or a thinner grooved plastic pulley for a round or V belt?
Next, I was able to easily pull the plastic pulley off the motor it came with. The brass pulley currently on the motor I'm using is on tighter and I am worried about any damage to the motor if I try to pry this off. Any ideas on doing this with little fear in damaging the motor or shaft?
I really am only considering this for the curiosity of it. I am just wondering if it will improve the performance of my setup or not? The drive diameter of both pullies looks very similar and as my motor is a D.C. servo I have trim pots for fine adjusting speed control.
Thanks in advance.
I have made a thread drive using the brass pulley. It rides up near the top (crown) of the pulley, but my speed trim control allows me to get the speed correct. The double square knot with a little dab of super glue makes for a strong connection and the knot does not affect the playback of the table at all. The strobe pattern on a disc remains frozen and the platter runs smoothly. The knot is really quit small and even watching it with your eyes only sees it quickly blip around the pulley. Factoring I have the thread drive taught enough but not so tight that it strains against either the platter or pulley. I am impressed with how quickly the thread gets my 10lb platter up to speed as well and it does not seem to drag as much when I lightly run my carbon fibre brush over an LP cleaning to get ready when playing.
looking for ideas
Hello,
After getting clear help from a respectable member ( called Pyramid) i know how to calculate the seize of the pulley i am going to use for a DIY turntable with the Sota Eclipse motor package.
Pyramid being the designer of this package is the one to follow, so to say.
My dimensions are in millimeter One '' is 25,4 mm
I just decided it would be better to have the belt running on the upper part of the platter where the inverted bearing is located.
The lower part is 400 mm diameter. The upper part is 360 mm.
Theoretically i think the distance from the belt to the motor should be limited.
The height of my pulley will be around 24 mm . On the lower an upper end there will be 2 mm high rim to prevent the belt from running of the pulley. Probably it will never happen BUT better be safe than sorry.
The '' belt area '' of the pulley will be around 20 mm high. With a conventional rubber belt the biggest diameter in that conical area will be 39,666 millimeter. Towards the rim that will change into something like 38 millimeter. The belt being close to 5 mm high dont know if the conic shape is enough or if i should go down to 37 mm or so.
I will also ask them to make a pulley to be used with mylar/vcr tape.. This belt will be more rigid especially if you are going for a '' thick '' one. Also being higher i think just a minimal conical shape like 1 mm difference will be ok to the center the belt.
The motor unit will be at close distance to the platter. I think motor axis and platter bearing will be something like 280/290 mm apart.
From what i read on the VPI forum the Pyramid design works very well so it could well be that it doesnt need a rubber belt to stop vibrations travelling into the platter. My diy motor housing machined from pom material will have several cavities of different seize and in all directions that will be filled with lead shot ( to kind of sink down vibrations)
The platter being heavy and big diameter will have a pretty high flywheel effect so i kind of hope that it will just keep turning. lol
The original Sota pulley which is to small for my situation has a threaded hole to secure it onto the shaft. Also theoretically this threaded shaft ( which will be empty for the biggest part with my bigger pulley) will destroy the distribution of weight in the pulley in the horizontal plane. I will ask the machine ''shop'' to make a close tolerance hole in the pulley that will give a fit that will just be sliding so i can add something like loctite 222 to make it stick. On the side of the motor a close tolerance hole for the shaft to enter until the pulley has a clearance around 1 or 2 mm to the motorunit. One the other side a threaded hole that will allow me use a bolt to '' break'' the thin layer of loctite.. If the clearance is according to the books with the right Loctite you can make a fix that is strong enough to last. It just must be strong enough . It is just a light load.
I think i will use some kind of aluminium. I think the company can do anodizing as well.
Will look for some tape now. I have some old VCR tapes it seems the clear starting part works nice.
Maybe so called Kraft paper used in transformers. Paper is strong enough i think to make a belt dont know how it will degrade with uv light, moisture temperature....
Greetings, Eduard
Hello,
After getting clear help from a respectable member ( called Pyramid) i know how to calculate the seize of the pulley i am going to use for a DIY turntable with the Sota Eclipse motor package.
Pyramid being the designer of this package is the one to follow, so to say.
My dimensions are in millimeter One '' is 25,4 mm
I just decided it would be better to have the belt running on the upper part of the platter where the inverted bearing is located.
The lower part is 400 mm diameter. The upper part is 360 mm.
Theoretically i think the distance from the belt to the motor should be limited.
The height of my pulley will be around 24 mm . On the lower an upper end there will be 2 mm high rim to prevent the belt from running of the pulley. Probably it will never happen BUT better be safe than sorry.
The '' belt area '' of the pulley will be around 20 mm high. With a conventional rubber belt the biggest diameter in that conical area will be 39,666 millimeter. Towards the rim that will change into something like 38 millimeter. The belt being close to 5 mm high dont know if the conic shape is enough or if i should go down to 37 mm or so.
I will also ask them to make a pulley to be used with mylar/vcr tape.. This belt will be more rigid especially if you are going for a '' thick '' one. Also being higher i think just a minimal conical shape like 1 mm difference will be ok to the center the belt.
The motor unit will be at close distance to the platter. I think motor axis and platter bearing will be something like 280/290 mm apart.
From what i read on the VPI forum the Pyramid design works very well so it could well be that it doesnt need a rubber belt to stop vibrations travelling into the platter. My diy motor housing machined from pom material will have several cavities of different seize and in all directions that will be filled with lead shot ( to kind of sink down vibrations)
The platter being heavy and big diameter will have a pretty high flywheel effect so i kind of hope that it will just keep turning. lol
The original Sota pulley which is to small for my situation has a threaded hole to secure it onto the shaft. Also theoretically this threaded shaft ( which will be empty for the biggest part with my bigger pulley) will destroy the distribution of weight in the pulley in the horizontal plane. I will ask the machine ''shop'' to make a close tolerance hole in the pulley that will give a fit that will just be sliding so i can add something like loctite 222 to make it stick. On the side of the motor a close tolerance hole for the shaft to enter until the pulley has a clearance around 1 or 2 mm to the motorunit. One the other side a threaded hole that will allow me use a bolt to '' break'' the thin layer of loctite.. If the clearance is according to the books with the right Loctite you can make a fix that is strong enough to last. It just must be strong enough . It is just a light load.
I think i will use some kind of aluminium. I think the company can do anodizing as well.
Will look for some tape now. I have some old VCR tapes it seems the clear starting part works nice.
Maybe so called Kraft paper used in transformers. Paper is strong enough i think to make a belt dont know how it will degrade with uv light, moisture temperature....
Greetings, Eduard
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There are things called pulley pullers. Very simple, but clever too. Example linked, but there are plenty to choose from...
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