Metal Shapers

by Kay Fisher

Fresh from the Internet we get this great observation from Steve Fleming. “I had a difficult experience cutting external keyways in a steel shaft about 6" long. I used a tool bit the width of the keyway (3/16") and managed the cut, but there was chatter all the way; and the bottom of the keyway shows definite chatter marks. The speeds were also varied in an attempt to reduce the chatter and the gibs adjusted on all moving slides and the ram to no avail. Reversing the tool holder as mentioned in at least one shaper reference book did nothing to help either. I have so far been unable to find any information about a good design for a tool bit or a technique that will solve the problem. It seems that slotting/parting in a shaper is at least as troublesome as in a lathe”.

Good point, Steve. I had the same problem. I was less resourceful than you however and gave up. I was on a mission to create a keyway and didn't take the time to troubleshoot the shaper problem until I got it right. Instead I just let the shaper chatter its heart out and cleaned up the slot with a hand file afterwards. I think the bottom line is making a keyway full width requires a machine with more mass to eliminate chatter. I also suspect that instead of using a square tool the size of the width of the keyway we should instead get a really big (in depth) tool like those used for cutoffs on large lathes. But this is an open request to all the Gazette readers who have shapers. Please email or write me and tell me how you accomplish slotting without chatter. I'm hopeful that the collective wisdom of our many shaper owners can shed some additional light on this problem.

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