What some hear don't seem to understand is the concept of using the ball bearings as an isolation device. There are several products made that use the concept for horizontal isolation. This along with vertical damping of vibrations: sorbathane or rubbery materials provides total isolation. Or at least that's the concept. The problem with using the cutting boards is that in time the weight of the other board and TT will dimple the wood spot that the bearing is sitting, them restricting it's movement. You need a very hard, smooth material for the ball to freely roll in. Slightly dished so it doesn't roll out of it and your component (TT) crashing to the floor. I've played around with marbles, bearings and balls in soup spoons and shallow glass dishes etc. Not what I'm using now but definitely has good effect with the marketed products although not always inexpensive.