On Wed, 31 Oct 2007 10:04:19 -0500, "Karl Townsend"
wrote:

Hmm...

Looks like I have the minority view here. You make good points.

For my lathe (10EE), I had awful time with cutoff with HSS tooling on
anything over one inch diameter. Tried everything. "The Kid" made me get an
insert cutoff tool and use power feed and lots o' coolant. Viola! my
troubles went away. YMMV

Karl



I also get on much better with carbide inserts than with HSS blade tools on
the ML7. Partly because of the more consistent chip breaker form and partly
because the holders are about 15 times as stiff.

The Myford doesn't have power cross feed, but I try to keep up a consistent
feed. I do not run the inserts at anywhere near the recommended speeds and
feeds (350sfm and 0.004"/rev) because the lathe just hasn't got the power to
do it.

I do use back gear to give me as much torque as is possible and control the
feed so that the motor doesn't bog down. Stalling the work invariably ends up
in a chipped insert. Not using backgear leads to chatter and chipped inserts,
since there isn't enough torque to keep the tool working. The insert needs to
be about 3-5 thou above centre and with no possibility of the work riding up
over it when getting to the centre of the cut, otherwise that wrecks the
inserts as well.


As a datum, I don't have problems parting off 4" 4340 with a 7" lathe and
1/2hp motor

Mark Rand
RTFM