This is the second ball mill I've designed, and I incorporated a metal grinder into it after retrofitting my first ball mill with one. While I don't often use them both at the same time, they can both operate simultaneously. It is fairly low-tech, and should be easy to build with limited resources. It is capable of grinding metals or milling powders to airfloat size.
To use the ball mill, the chemicals to be mixed/crushed are loaded into the milling chamber (A), and then it sits on drive cylinder (B) and spins for an extended period of time. To use the metal grinder, a peice of of scrap metal is clamped to the hinge (C), and a weight it attached to it. It rubs against the wet-or-dry sandpaper wrapped around the drive cylinder (B), which is kept cool by water in the metal collection tray (D). As the metal is ground, it collects at the bottom of the metal collection tray (D). The whole machine is powered by a modified Kitchen-Aid mixer, although this could easily be substituted for by a motor and simple transmission, as long as the drive cylinder spins at about 100 rpm. To ensure porper functionality, the drive cylinder surfaces and the milling chamber cylinder surfaces that touch wrapped in non-slip tape (E). Finally, the bushings are lubricated with thick grease.
All CAD are SolidWorks files. See Links for SolidWorks viewing software. The two profile files are needed only to modify the frame extrusion profile. 03-00 is the top level assembly. A .zip file of all the CAD is available to save you clicking. It does not include the profile files.CAD.zip
This is a full set of technical drawings. A .zip file of the whole package is available to save you clicking.Drawing Package.zip