"D Murphy" wrote in message
...
greybeard ""greybeard\"@mcleodusa,net wrote in
:

Higher speeds mean more heat on the tool, higher feeds mean more
pressure, it's up to the operator to find the balance.

Higher feeds mean higher cutting force, measured in pounds, not PSI.
Higher
speeds lower the pressure (PSI not Lbs.) on the tool tip.


I would not recommend going to more than somewhere near .025 feed on
anything, as far as single point tooling is concerned, you're asking
an awful lot of that tool in terms of pressure that it has to stand.
If you're looking to save time, moving the carriage back, feeding in
and starting it again take time. Higher feeds will generally give
less tool wear, but not without it's own cost. Light cuts are
something I try to stay away from, they seem to wear the tool faster
than a heavier cut.

Lighter feeds do wear the tool sooner. Consider turning a one inch
diameter
for a one inch length. Each turn of the spindle at a one inch diameter
means 3.1416 inches of material will pass by the tool tip. At a .001 IPR
feed rate 3141.5927 inches of material will pass by the tool tip in a one
inch length of cut. Kick the feed up to .010 IPR and only 314.1593 inches
will pass by the tool tip in the same one inch length of turn.

So not only does turning too slow waste time, it wastes tool life.

--

Dan

Dan,
Your last two posts make a lot of sense to me. Thanks for the illumination.
If I am following this correctly the tool radius would limit the feed rate
as, if you exceed the radius in feed rate you begin to make threads and a
rough finish. I tend to leave my feed rate set at .0042" and adjust the
depth of cut and speed to get "happy sounds" from the lathe I can see
from what you have said that I should be trying to up that feed rate to
reduce tool travel time and wear. The QC box on my lathe has feeds listed
from .0078" to .0042" so I have always stayed below .01" for feed but it
looks like I could go up to 100 TPI on the threading chart and have a
reasonable feed rate for a tool with 1/64" radius.
Am I close to correct here?
Thanks
Glenn