Lloyd E. Sponenburgh wrote:
"Terry Coombs" fired this volley in
news:mknpap$594$1 @dont-email.me:

They're also supposed to work really well to ball mill homemade
black powder .

Not even close, Terry. The minimum 'correct' load for media to
properly ball mill (anything) is 50% full, with 25% of the empty
volume in material to be ground.

Typically, amateur BP-makers use hardened lead media -- about 1/2" in
diamter for that particular 'tumbler'. When filled with 5lb of that
lead, the thing will hardly turn over, much less turn at the optimum
speed (about 90rpm) for that 4-7/8" i.d. jar.

It requires re-work of the support bearings AND the motor's being
replaced in order to mill continually at the proper speed.

Some of those folks who report that "it works fine" are also reporting
milling times as long as 24 hours. At the proper speed and charging
factors, it will produce better-than-commercial BP in 2-1/2 to 4
hours.

Lloyd (who wrote the book on it "Ball Milling Theory and Practice for
the Amateur Pyrotechnician")

I did not realize they were that far down in quality . I gotta get back on
my ball mill project , got all the major pieces cast and/or machined , just
gotta start stickin' stuff together .



--
Snag