Thanks charlie.
I still have to figure out a few things.
I don't think I will need all that many balls. I am not very worried about efficiency. With the lifters/paddles, with a proper rotation speed, the mill should pulverize materiel quite well. Mill manufacturers don't use them much because they wear out so fast. Mine will be simple and easily replaced.
Rotation speed can be modified fairly easily and numerous ways.
For tires, to add friction, I went by my friends shop and got an old but still in pretty good shape timing belt and if I can't make that work, I figure a 'V' belt or some of the high pressure hose I have may work better.
I can also put 3/4" inside dia. hose on the shafts if need be.
I am only going to use the big mill for charcoal and ingredient grinding when they are not mixed in dangerous formula's.
It will most likely end up mostly sitting around like many of my other bright ideas.
I have one of the little harbor freight tumblers for making small batches of powder.
I wish I was good at math and figuring problems.
My motor turns 1500 rpm. The motor pulley has 4 3/4" of belt travel, my 10" pulley has 31".
Bare, as they are now, the shafts have 2 1/2" and the bucket rim is a total of 38 inches in circumference or belt travel.
I have a water leak to concentrate on for now and will try to figure it later if some kind soul does not do it for me.
My first try at figuring it came to 15+ rpm but I doubt I am right.