Has anyone cut smaller parts where it requires tumbling the parts to smooth them. Like a key chain or some hand held gadget.
are the edges sharp after cutting with plasma using .6mm or .8mm tip. I know water jet cuts are extremely sharp
how smooth can you tumble a small part?
i actually use a concrete mixer to tumble parts. they are usually 1/4 or thicker. i use spent blasting media and the small plug that comes out of a 1/2 hole that i cut a lot of. It works great and the neighbors love me 
i guess with the right setup you can use a tumbler for small parts i would worry about thin stuff getting bent.
I have a vibratory case tumbler that I used to use for reloading. I tried using it with some triangular media from harbor freight to smooth small parts… the parts always seemed to find each other and stick together, preventing the media from touching the parts in the middle of the stack. It was a failed experiment.
It would probably be more effective on thicker steel, but it was useless on 16 and 14 ga parts.