"jim rozen" wrote in message
...
snip-----

Hmm. After roughing out, I typically do the side relief
and front/back taper on those, with the periphery of the
wheel, so they do wind up being circular sections, ie
'hollow ground.' Seems like that's the only way I can
get them to have the profile I like, accurately. I can
tell how worn they are getting by how wide they are -
I sharpen them right across the front. The one on the
machine right now is down to 0.088 wide at this point.

Jim

Exactly as I do, too. I've found that the tops of parting tools respond
well to the radius of the wheel, so I grind what surely must be no more than
three degrees of positive rake on the tool as an almost last operation.
One has to start well back of the edge and extend the grind back to the
solid portion of the shank. Tools seem to have superior chip flow and
cutting ability with this minor variation. The only negative is as you
push the tool back from sharpening, the cutting edge drops slightly, so they
must be shimmed up. I keep a huge collection of shims on the headstock of
my lathe, so that's no problem at all. For those that use the insert type
tool holders (KDK, Aloris, etc.), it's a simple screw adjustment.

Harold