I find tumblers to be a waste of time and not worth the bother. I bought one years ago, and found there was as much clean-up of the parts as I was doing by hand(once you include picking the media out of parts), and it was noisy and loud. So I switched back to just polishing parts by hand...this solution clearly isn't for everybody. )
Anyways...I'll sell you my Lyman tumbler cheap is you want it...I never use it. It's one of these:
Send me a PM if interested...
Sean