Here's a rotary broach that i just made. It not my idea, the gentleman that goes by arduinoversusevil on youtube is were i got the idea from. Its made out of stock from some center punches that came with my lathe.
The trickiest part was turning the offset. I did it on the 3 jaw by putting .140" shims on one of the jaws. The hole for the bearing is just the profile of the bit i used to drill them, nothing special. I just made sure that the ball would stick out of the hole just under halfway on all the holes. The holes for the bit were supposed to be temporarly round until i could make them square with the broach, but they work just fine like that. Profiling the tools was the biggest pain. I used a dremel with a ball attatcment. So far i only used it on a drill press. It makes square holes. I was also considering making more dies for it using actual tool bits, like an actual allen key sharpened to make hex holes maybe torx and the like. They are hardened, so it should work. Any questions please ask.
The trickiest part was turning the offset. I did it on the 3 jaw by putting .140" shims on one of the jaws. The hole for the bearing is just the profile of the bit i used to drill them, nothing special. I just made sure that the ball would stick out of the hole just under halfway on all the holes. The holes for the bit were supposed to be temporarly round until i could make them square with the broach, but they work just fine like that. Profiling the tools was the biggest pain. I used a dremel with a ball attatcment. So far i only used it on a drill press. It makes square holes. I was also considering making more dies for it using actual tool bits, like an actual allen key sharpened to make hex holes maybe torx and the like. They are hardened, so it should work. Any questions please ask.
