I recently made a video on how to make your own quick and dirty hex broach from scraps or bar stock. This is a fun trick that we used to do at 5012 to clean up hex bores from 3d prints or machined plastic parts.
It’s far from a “good” hex broach but it’s nice to have in a pinch, especially if you have an arbor press that’s too small for a real broach.
Definitely a fun, useful part to make for lathe training as well!
Note: In the video, I use it to open up the hex bore on a colson wheel from vex. I do not recommend this for FRC drivetrain applications since they’re sized to minimize backlash.