I wasn't too keen on spending around $250 on a grain mill so I made this from an old Chrysler Borg Warner auto gearbox drive spline and universal gears. Next step is to pretty it up a bit with some paint, so far it works really well and it doesn't get any cheaper than free! (free scraps and leftover car parts anyhow)
I chose the drive splines because they were made of extremely tough steel and had grooves already cut longitudinally which are perfect for grabbing grain and crushing it.
I dismantled the universal gears which gave me two crosscut gears, the tooth depth is deep enough that it allows for adjustment I welded a blob on top of the spline then lathed it down to the inner diameter of the gear which then sat snug with a few hits.
I filled the cavity with weld and lathed it flat on the end with a countersink (the other end already has one from the factory) for the turned brass pivots to hold it in place and adjust the crush width.
The body is steel plate, thick enough to tap a good thread into to hold the pins. The splines were buffered and lined up with a few thin washers (which are plentiful in the gearbox). The brass bolts were tapered to match the countersunk holes and a nut is on each to prevent them from tightening and jamming in use.
While I was at it I welded a hopper to the top and burnished it flat covering the sharp edges with a protective auto strip from 'rare-spares'. The handle is just there while I was testing but the shaft has two nuts to put the chuck of a drill over.
** in practice: The mill works great and there is no give in the set width so that everything that goes through it is properly crushed and I have not needed to run it through twice.
The hopper bottom feed could be wider to let the grain fall freer.