I have a ZenToolworks CNC router, and it had no way to manually
move the router, so I made handles that go over the end nuts for the X and Y axis threaded rods. This way I can use the router
manually for small stuff, and they don't interfere with normal
operation. Basically, they fit over any 14mm (.558) diameter (across flats) nut. There is a small hole that transverses the hole where the nut goes, that can be tapped for a #2 (or similar) screw, to lock the handle on the shaft. I found that PLA taps well, and the plastic
seems to help keep the screw from vibrating out.
Simple print. I used .21 layer. 2 solids top and bottom, 5 perimeters, .25% infill.