Materials and motors and frames and mass. So many factors.

Rrock liners are typically rubber and in a hex shaped rolling box.
But rocks are turned in everything from thimbles to cement trucks!
Martin

Michael Koblic wrote:

"Ecnerwal" wrote in
message
...
In article ,
"Michael Koblic" wrote:
Of course rotary tumbling would be simpler...

And quieter, most likely. The rock shop near where I grew up had an
elaborate tumbling setup consisting of one long driven roller, one idle
roller, and a bunch of car tires (hold up to harsh media, contain
water/fluids, deaden sound.)


I am told that in principle vibrating is quieter than rotary tumbling.
But I suspect that it depends a lot on the actual equipment, liners etc.