I have been, too. I grow a bit of rye and wheat here, and hand threshing it is a serious pain in the arse.
BBQ joint not far from here has an antique one in front of their place, and I keep meaning to go by and take pictures of it for reference. It's about 7 ft long, and looks like it can either be hand cranked or put on a belt from a tractor (like anyone has those anymore).
Let me know what you come up with. I've looked at a lot of youtube videos of folks trying to build their own.
/johnny
Are you sure that’s not a fanning mill? Those were used to clean the threshed grain and many of them are still around. I’ve got a line a ‘Clipper 2’ model and it has a few extra screens.
The thresher beats the grain off the stalk and then, should, knock the hull from the grain as well. The fanning mill removes the hulls and foreign debris. Getting the grain free of the hull is the big trick, IMO. Especially oats.
What I’m thinking of is a sloping drum with internal ribs or grooves that act as stationary resistance to an internal shaft rotating on the same axis with an array of rubber fingers that strike the ribs and the grain caught between. Gravity would feed the drum (or trough) and exhaust the materials. The ribs would retain the grain just long enough to get the hell beaten out of them before exiting. Sketching ideas is about all I’m doing now because the barn has no heated space to work in yet.
Oh well, sooner or later I’ll get something to do the job. Like you, I’m flailing in the dark, too.
Jack up car, and put on blocks. Remove wheel, and remove tire from rim; put rim back on axle. Put belt around rim.
This works best & safest, but only if you have a Positrack type rear end. The Posi keeps the wheel driving the belt from stalling, while the opposite one spins.
Otherwise, BLOCK THE OFF-WHEEL THOROUGHLY, and leave it on the ground, while only blocking up the belt-driving wheel. The weight of the car should be enough to let the jacked wheel drive the belt, instead of spinning the grounded tire.
I've seen diagrams & read articles describing how to jury rig a locking lever onto the off-wheel's lugs, after removing that wheel, but haven't seen it put into practice.
To get an idea of what I mean, here is nearly the same principle used for a log splitter, rather than a belt-drive.
Some guys get fancy, and weld two rims together, and do what they need to to the center of the outer one to be able to bolt the unit to the hub. This has the advantage of placing the drive belt beyond the fender well, eliminating any clearance problems.