Rim Drive Mod or how to make it even better


I was going to just add this post to a previous post regarding the VPI rim drive, but this is important and I want all those who use the new drive to know this. I just spoke to Harry W who told me that if you use sorbothane, or soft felt, etc, under the feet of the motor/flywheel assembly, the sound is even more improved. Don't use it under the turntable itself...only under the motors. I tried it and it REALLY works.
128x128stringreen
Good idea. I think I'll try that. I'm not really feeling like spending $300 for the mini-feet just so I can gain the extra height.
After about 4 days of running the rim drive 5 to 6 hours a day, I see very little improvement in speed stability. If I put my ear to the rim drive, I can hear the noise of the "thicker" portion of the belt contacting the platter. Whether the belt is actually thicker at some point on its circumference, or just isn't seated yet, is anybody's guess. At that moment the platter speeds up slight, then slows down. This repeats over and over, and the KAB speed strobe confirms this by showing the "33" rocking back and forth ever so slightly.
My guess is that I will put a call into VPI tomorrow, and unless I get some recommendation that sets things right, will likely go back to the belts until this upgrade is ready for prime time.
Cheers.

Tom
TFK..Have you put a soft material under the motor assembly, and make sure the turntable itself is solidly resting directly on your table?? That soft footer/solid setup completely cured all the problems...and it sounds absolutely stunning. MUCH better than the belt drive. Are you using a platform of any time?? Try it without.
I don't use a platform of any kind. My stand is a Billy Bags audio rack. Welded, single piece construction, and rock solid. I have tried some felt, and some furniture slides under the motor. Both help, but they don't come close to the speed stability I get with the belts. Do you use a KAB speed strobe, too? Is your speed dead solid 33?

It would be nice if I could check out someone else's system and compare. Any one else running the flywheel upgrade in Chicago?

Stringreen, when you put your ear right next to the flywheel, can you hear any contact noise between the flywheel O-ring belt and the platter? I sure can. It's a "scrape, scrape, scrape" kind of noise that occurs once every revolution of the flywheel, when the area of the belt with the slight bulge to it contacts the platter. And if I press my finger in between the motor assembly and the TT plinth, I can feel the motor assembly rocking back and forth. Granted, it's a VERY slight rocking, but that rocking will surely transmit far more vibration to the table than a belt hooked to a motor flywheel...

Thanks again for the help.

Tom

I just turned on my table and put my ear right up against the motor assembly and heard nothing.. It is very quiet indeed. I would call VPI. I don't know when you got your new drive, but they have just changed the formulation for that belt. Call Harry and have him send you one of the new belts. I'm sure (but not positive) he won't charge you anything. You shouldn't be unhappy. It is really excellent. I thought I was going to change it back to belt drive when I got my unit, but I was able to stamp out all of the bugs. I am really happy with it now. I know you will be too. Call VPI tomorrow.
OOPS - I didn't respond to your speed question. I use the VPI strobe that came with the Supscoutmaster, and a neon light I got for about 3 dollars at Home Depot. When I first installed the rim drive, it ran either very fast or very slow - I forgot which, however, the SDS adjusted the speed perfectly. Those hash lines just stay solidly put.