Quote Originally Posted by indiej View Post
the pc will orbit no matter what. the counterweight will minimize the jiggling. 7424xp instruction recommends the proper counterweight for the size of the foam pad attached.

edit: oops, rockstar beat me to it and has the better presentation
The more precise the counterweight for the backing plate the less jiggle or vibration, we've seen the difference between a counterweight for the 5 and 6 inch pads but its very hard to find 6 inch pads counterweight but it really does offer less jiggle, i think it can be found with powertools sellers