Chipbreakers on HSS

[Arbo]

Doing som turning on 2" CRS in the lathe. I am using 3/16" HSS, 900RPM, and a rather slow feed which I am not sure of. Absolutely beautiful surface finish, requiring only minimal polish. I can cut one continuous curlyQ, the full length of the cut, Problem...I don't want to...IT MAKES ONE HECK OF A MESS. So, how and where do I grind a chipbreaker on a HSS bit. Thanks in advance.

[Mike Burdick]

Arbo,

This is how I do it, I'm sure others may have different methods.

When I sharpen the tool bit I use a very thin cutoff wheel - 1/8" or less in thickness and about 4 1/2" in diameter. This way, the sharpened end of the bit is very small which forces the chip back on itself. The bits are sharpened with the usual side rake, back rack, etc but the thin wheel allows me to grind all this within 1/8" or less - thereby creating a good chipbreaker. The main idea here is to make a "wall" to force the chip back and break it.

For really tight chipbreakers I have even used a Dremmel tool equipped with one of their tiny cut off disk to sharpen the tool bit. Just depends on what's needed.



[This message has been edited by Mike Burdick (edited 04-25-2004).]