"Bill Noble" fired this volley in
:

isn't this a metal working group? to make a rock tumbler all you need
is an old BBQ motor, a couple of steel bars that you cover with tight
fitting flexible hose, and some bracketry to hold the mess - direct
drive one of the rods with the BBQ motor. use any plastic jar for the
tumbling jar.


Right. Read something on Ball Milling. There's something more to it
than what Horrible Fright might tell... and it doesn't take two weeks to
"tumble" a bunch of dull, worthless rocks into shiny, worthless rocks --
It takes about 24-36 hours in an optimized mill. In fact, it takes about
the same time to change loads and wash between grit charges as it does to
do the actual grinding. If you wanted to do the whole job in three days,
you'd be working after midnight two of them.

LLoyd (who _actually_ wrote the book on the subject)