Keyway Broaching

[Jonathan W.]

Does anyone have expierence with keyway broaching???

We are trying to make a 1/8th keyway into a 1/2 inch sprocket hole.

What are the proper stepts to take so that we dont snap the broach?

[Aren_Hill]

do you have a keyway broach set? a set of shims?
by my experience you just put it in an arbor press use some oil and make sure its straight up and down, not to difficult.
run it through then use the appropriate shim to get the groove depth required.

hope that helps

[Ben Piecuch]

Sounds like you have the tools, you're just looking for some advice.

I always tell my students to take the first few notches slowly, and always back off the arbor press after 1 or 2 notches. If the broach is slightly offline, it will snap fairly easily. By backing off the arbor, it allows the broach to realign itself vertically, and you can press again. Be sure that your arbor press is aligned properly.

Lubrication is your friend.

And, we've found that we need to do a third pass with the broach, but from the back side of the part. For some reason the 2nd pass hasn't been cutting deep enough for us, so we've had to flip the part and finish the keyway from the backside. Odd, but it's a new broach set for us this year...

Best of luck,

Bengineer

[Gdeaver]

I assume your cuting the keyways for the Andy mark trans. You may have to do a little filing to get the key in the output shaft keyway.