VPI SDS speed issue

Have you checked the consistency of your voltage from the wall? Does it vary a lot?

You may find plugging the SDS into a power conditioner helps stabilize it.

Go to the VPI website and download the SDS calibration manual. If your SDS goes from 115v => 84v => 72v then something is wrong because the SDS is only programmable for a single step down voltage i.e. 115v => 72v. The step down voltage can be programmed by the user. Depending on the age of your SDS, the factory default is set at either 72v or 84v. Try recalibrating your SDS and report back.

There is a PDF file on VPI's website on how to access the calibration mode on the VPI SDS. This file was not included with the standard issue owner's manual.

But, to me, it sounds like you have some sort of problem with your Unit?

Yes, the SDS should initially start up upon turn on to 115VAC, then drop to a selected lower voltage, and the factory default setting was said to be 72V. Then it should stay at that prescribed lower voltage setting, and not change while the unit is in use.

Not until it is then shut off, and turned on again, will it again go through the same process I mention above.

I'd definitely get ahold of the folks at VPI, and describe your problem. I'm not knowledgeable enough to troubleshoot your problem, which could be a fault with the SDS itself, or perhaps some other problem, such as a wiring, or Capacitor problem with your Aries Table?
Mark