Blind keyway broaching
Blind keyway broaching
(OP)
Does anyone have any good suggestions for what process to use to rapidly broach a keyway (approx 1/4") in a 1 1/2" dia. blind hole? E.D.M. would be too slow of a process to be cost effective.
Thanks in advance for any help you can give.
Thanks in advance for any help you can give.





RE: Blind keyway broaching
Lock the spindle in place so that it does not rotate.
Mount a short as possible boring bar that has a 1/4"
square with a 45 degree angle. You will have to grind
clearance on the lathe bit. With your part centered
in a vise and your tool bit mounted, move x axis toward
the ID of your part, set your z depth for the blind keyway. If you are using a bridgeport type mill you may have you use the handle to take the shallow cuts to depth. If you
use a cnc mill you may program the head to come down to depth, go back up move x (depth of next pass) repeat.
I have done this on several occasions and it works great.
RE: Blind keyway broaching
RE: Blind keyway broaching
You will need a relief at the bottom of the keyway to allow the chip to break free. A groove all around the part works good, as there is no part index. Another solution is a drilled hole from the side for chip relief.
In the old days, it would have been cut on a shaper.
RE: Blind keyway broaching
Viktor
http://viktorastakhov.tripod.com