I have used 2 wet grinders, with 3 different stones, sand stone, white
alu., pink alu,.

Before use I trued every stone, but after some time they all developed
some vertical movement.
A friend tells me all wet grinders do this unless you run them
continuously.

I think of buying a Tormek system, but would like to be sure it will
behave better.

Does anyone know what causes the movement?
Is it deformation of the stone?
Wears the thoroughly soaked part of the stone faster (or slower)?

What is the experience with Tormek systems?

Thanks,
Hans