While this isn't a truly ideal coupler, it should work sufficiently well.
Get yourself some flexible "high pressure" hose at Home Depot. The stuff with the fibers embedded in it. Get it for 1/4" inner diameter. Cut off a piece that's about 1 or 2 inches long.
Take a drill and drill out a 5/16" hole in one end. Tap it with your 3/8" tap.
Screw it onto your threaded rod, and just to make it secure, add a worm hose clamp over the threads. Now, slip it onto your 1/4" motor shaft, and use another worm clamp to secure that connection.
Works amazingly well, and costs virtually nothing. In fact, if you find someone nice at Home Depot, they'll often GIVE you a piece that small.
-- Chuck Knight |