Lloyd E. Sponenburgh wrote:
"Terry Coombs" fired this volley in
:

I'll need to put the finishing touches on one of my drums and
load it
with some lead balls to see , but I suspect it is . The 3 speed fan
motor I have is I think a 1/4 hp , has all the controls attached ,
and should work fine . It's OK , this motor will work for a couple of
other projects I have in mind for the future .

Terry, from my book on ball milling (but also an industry-standard),
the speed of a dry ball mill should be about this:

RPM=0.65 * (265.45/sqrt(jar_id"-ball_od")

That's expressed in inches for the id/od figures.

That speed ensures adequate 'slump angle'to ensure the media falls as
far as possible with as many strikes as possible on the way down,
while not centrifuging the media out to the jar walls. It also
presumes that the jar is 50% full of media, with a material charge
equal to 25% of the empty jar's volume.

LLoyd

Thanks Lloyd , by that calculation I need about 143 RPM . I'll have to
check the chain drive ratio and figure the FPM of the roller shafts to see
what I'm getting from it now . It might not be too fast after all .
--
Snag