hand crank for hex bits

prusaprinters

A simple hand crank for hex bits, utilizing a 608 bearing.I made this crank specifically for my USSA Router Lifter 3.0, but of course it might be useful for different applications as well. I made it relatively short to not interfere with the top-suction or router bits, but also because I noticed that longer cranks felt bad in terms of speed.For proper installation, you'll need1x 608 ball bearing (any style will do, but I recommend the sealed 2RS)1x M5 nut1x M5x30 bolt, counter sunk head1x ¼" hex bit in your needed size (I use 5mm)(optionally you can use an M5x30 bolt with a hex head, in that case I'd recommend a stopper nut and an additional washer though)The tolerances are tight as this crank is not meant to switch bits on the go; it's more of a permanent installation. I needed the force of a vice to press-fit the bearing as well as the hex bit.Install is fairly simple, just install the bearing and hex bit; then put the M5 nit into the handle, push it through the bearing and secure it with the M5 bolt (if you opted for the M5x30 with hex head, push that one from the top of the handle instead of the nut and secure it from the other side of the bearing, ideally with a washer in-between; a stopper nut is prefferred). printing adviceI recommend a sturdier filament like PETG or Tough PLA. For the arm, four or more walls are recommended. Print as fine or coarse as you like.