Like Jason I have a Tormek, but the Scheppach is a copy of this.

Is the apparent out of shape on the circumference or the sides? If sides maybe it is shifting along the spindle, also spindle wear would also make it wobbly. They do go so slowly that wear is likely to be minimal, but worth checking.  Greasing the journals may help.

When using it after the stone has dried out, do you leave it running in the full water trough for a while until the stone is fully soaked before using it. The stones absorb a good deal of water..

Quote from the Tormek instructions

  "Fill the trough with the grindstone running and the trough raised until the water reaches the MAX WATER LEVEL  line.   Continue filling until the stone cannot absorb any more water, which is approx. 1.2 litre (2 pints).   The stone must run in water at all times when grinding."

Thirsty ain't it.

Edited By Robbo on 04/11/2014 10:17:03