How to cut lathe/mill wheels?

[Naiveambition]

the cheap plastic handles on my mill have broken too many times so I ordered cast iron from grizzly. For a decent price I was able to get all three for 40$. They come un machined to fit. My mill uses the word the three prong cog. My question is how to make the cut.

What I do know is there are three passes to produce the cut, so degrees and offset are my hang up. Anyone got a simple solution I'm not seeing.

 

[Jasonb]

Should just be 3 cuts at 120deg spacing with on edge of a milling cutter on the ctr line of the hole, dia of cutter to form the inner edge of the dog tooth.

You don't acuually need the turned recess that is shown in the first two pics

 

[Naiveambition]

Awesome, just what I needed. Thanks.