On Fri, 15 Feb 2008 10:08:56 -0800, Frank Warner
wrote:


Over the years I've collected a variety of end mills, mostly from sets,
all center cutting, 2-flute and 4-flute (I understand the difference),
single end and double end. Must have 2 or 3 dozen of these in different
sizes, all dull.

In fact, they seem to go dull incredibly fast, although they cut fine
when brand new. Might be my technique, might be the mini mill (not
rigid enough), might be I'm not holding my mouth right. Might also be
because they are the cheapest end mills available so they can be sold
in sets for $35 or so.


Pay critical importance to the speed you are turning them, and how
fast you are feeding them into the work.

Do you actually know what the spindle speeds are? If so..try this...

http://www.whitney-tool.com/html/cal...SpeedFeed.html
http://www.carbidedepot.com/formulas-milling.htm



Speed and feed calculators are of great help. Particularly for those
who dont mill enough to be able to See whats going on.


Most inexperienced folks tend to spin cutters way too fast and feed
too slow and burn the edges of the cutters off.

Blush..been there, done that..I was particularly bad about that when I
first started. Got a pretty good pile of dull (and broken, burned,
mangled, snapped etc etc) endmills going the first couple years, until
I learned better.

Gunner, who buys surplus tooling




"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner