Well Nunyas ,you've just mentioned my latest plan. Im gonna take the heating unit out of an old dryer, install a smaller compartment in the original drum, route the motor through a rheostat to vary the speed, and viola! giant rock tumbler.
What I was trying to build was a "vibratory tumbler". In that setup the drum is mounted on springs, and the motor just has an offset weight in the shaft that causes the whole assembly to shake or "vibrate" It dosen't actually turn the drum, like a true "tumbler"
I've decided the vibratory tumbler needs a much faster motor than I have on it now, like a vacuume motor, and to be effective they all seem to use a "Jello mold" shaped bowl, which really dosen't work for the larger carb parts. I'm gonna keep tinkering with it, but I think the "drum tumbler" style is more suited for what I want to do.
Now I gotta find an old dryer..... /ubbthreads/images/graemlins/devilgrin.gif