SSM w/Rim Drive - Cloud 11 Vibration issues?

Agreed, the rim-drive motor/flywheel assembly and the TT plinth should rest on one slab in order to fix the geometry between the two. Any play between the motor/flywheel assembly & the platter will compromise speed stability.

You could fix things and preserve the benefits of decoupling from earth via the Cloud platform, by elevating an oversized wood or slate slab on top of your existing Cloud base. Slate would do the best job of absorbing motor vibration. Cones could be used for elevation, or perhaps the new slab could simply replace the top of the Cloud.

This is an E-mail I sent to VPI with Harry's answer regarding the rim drive

Date: Fri, 30 May 2008 10:50:55 -0700
From: vpi_help_4u@yahoo.com
Subject: Re: Suggestion
To: sgreenp@msn.com

Hi Stan, it's interesting that with the belts you need everything solid but with the Rim Drive you need a small amount of lossiness on the feet of the motor assembly. If you have any sorbothane or thick felt or anything that has a bit of give put it beneath the feet, it will solve any problem like this. Try it, you'll see.

HW

Stanley Green wrote:
Hi - I have a Superscoutmaster, 10.5i, with a new Rim Drive that you helped me with. I'm hearing a speed inconsistency now that I never heard with the belt drive. I lubricated the motors and the turntable, but that didn't seem to help. The numbers in the SDS don't seem to be inconsistent. The out of tuneness is a slow kind of wavering. Do you have any suggestions?? Thanks Stan Green

Stringreen,
It sounds as though the felt or sorbothane has pretty much smoothed your SSM out. Did you order a set of the softer feet or are you satisfied with what your using. Mike at VPI told me this week that they are designing a softer O-ring to use as the drive belt that should smooth out the drive even more with or without softer feet.

These posts suggest that there is a significant amount of noise & instability generated by VPI rim-drive motor/flywheel assembly. It would be interesting to compare this to Teres rim-drive, which is allegedly a quiet motor. Sayonara.

I am actually using a soft gummy kind of material that once was a mouse pad. Naturally, I tried many different materials, but this was better than the felt. I am very happy with my rim drive setup now. It is far better than when the belts provided the power.