"Bob Engelhardt" wrote in message
...
Michael Koblic wrote:
Has anyone ever made their own vibratory tumbler? Does anyone use one to
tumble small steel parts?


I made one from a 20 lb propane tank & treadmill motor:
http://www.metalworking.com/dropbox/vibepolisher.jpg
(Your browser may resize the jpg to fit your screen. Clicking on it
should return it to full size.)

Works well, but is VERY loud.


Very nice! When I read your post and the words "propane tank" I expected to
see a rotary tumbler (there is one on the Youtube), but no, your is the true
bill! Looking at the work involved I suspect that forking out $150 or so for
a new does not look so bad. I was not clear about the concept: The motor
spins an arm which moves the bowl in a circular eccentric fashion? I somehow
expected the movement to be up and down. Presumably the adjustment would be
achieved by regulating the length of the arm and thus the amplitude of the
vibration. The frequency of the vibration is then given by the motor rpm (I
guess yours is adjustable being a treadmill motor). I see the recommended
frequency is no less than 1600 Hz so an ordinary induction motor would do.

I have done a ton of research on this but eventually one has to get one's
feet wet. I was reluctant to spend money only to find out that the whole
thing is completely useless for my purposes. I am actively looking for
someone who has one to tumble a couple of my parts and see if it does the
job.

There seems to be a whole spectrum of people who use tumblers: Those who
treat it as an art and science and who pay attention to the exact size,
shape and constitution of the ceramic/plastic/hardwood media, added
compounds etc., and those who spin coffee cans with cat litter :-)

BTW I like the coffee can on a woofer - nice video on Youtube :-)

--
Michael Koblic,
Campbell River, BC