I'm using 18mm MDF as that's what I had laying around
1 x dimmer switch
1 x sewing machine motor
1 x old computer cable
2 x connector blocks
and a bunch of screws
Step 1: Rollers
If I had of thought about it a bit more I should have used round nails but hey too late now.
On one roller I need to form a indent for the drive band of the sewing machine motor to sit, this will stop it moving up and down the roller. to do this I used my drill as a make shift lathe, and just pleased a round file on the stick until the groove was at the right depth.
Step 2: Prepare the Board
and mark up the board for where the motor will go and the other parts, also marking up the holes.
drill the holes and counter sink them.
Step 3: Attach All the Supports and Axels
when you attach the second axel support you need to insert the rollers, making sure the drive band is over the drive roller, the one with the grove in it. then attach the second axel.
Step 4: Add the Motor and Wire It Up
put the drive band on the motor, if you have done everything right it should be fairly tight, it has to be otherwise it will not drive the roller.
now just wire up the switch and attach it to our computer cable and we are done!
the dimmer switch can be used to control the speed of the ball mill, if you need to time it you can just plug it in to a plug in wall timer.
should your containers not contact the rollers properly just add a few strips of bicycle inner tube to the outside of your container which will give it better grip.
thought I would add this video of it working, using lead media, see my instructable on how I made the lead media.