On 2009-06-24, Randy wrote:
On Tue, 23 Jun 2009 21:39:51 -0500, Ignoramus17181
wrote:

This is my first time broaching.

I am broaching a keyway slot in a pulley bushing. The hole is 1 3/8
and the slot is 5/16". The reason for needing to broach is that I had
to bore this pulley from 1.25" to 1 3/8", to accommodate a larger
motor shaft.

I am finding it difficult to do with a 3 ton press. It does work, but
I feel at the edge of this press's capability. I am concerned
that, perhaps, I am doing something wrong, or the broach is dull. So,
my question is, what would be a normal force required for broaching
iron bushings with a 5/16 broach. The bushing is about 2 inch deep.

I am using tapmagic cutting fluid.

i

Check here

http://www.dumont.com/prodc.html

a 5/16C broach at a 2.5" loc will need 3960 pounds to push it through.

At 2" LOC you're most likely at 3000 or so......


Thanks. It would seem, then, that the broach is a little dull.

DuMont sent me a document on broach sharpening and I will try to
sharpen this broach.

In any case, as I said, I broached the bushing from that Browning
pulley, and it sits securely on the motor's shaft.

i