"Harold and Susan Vordos" wrote in message
...

"jackK" wrote in message
news:0iwVd.2186$ju.517@okepread07...
Harold and Susan Vordos wrote:
"Jon Elson" wrote in message
...


Harold and Susan Vordos wrote:


"Grant Erwin" wrote in message
...
snip-----

You will when you're faced with a serious application. Don't think
so?
Try using a 4 flute half inch end mill taking a serious cut (full
width

and

half inch depth) on some ½" 6061-T6 aluminum plate, high spindle
speed
(4,000 RPM) and fast feed. Then lets talk.



Well, I NEVER run an end mill with a plunge depth equal to the
diameter.
My general rule is that the plunge depth should never be more than 1/2
the
tool diameter, ESPECIALLY when cutting at full width. Maybe some
end mills can take this, but to my mind, that is really pushing
things.
Of course, on a finish pass, I might use the full length of cut of the
cutter,
but the width of cut is real light.

Are you talking about solid carbide cutters, here?

Jon



No, HSS, which can deal with a cut of that nature with no problems as
long
as you don't subscribe to the theory that how an end mill is ground
makes no
difference as to performance. The amount of relief for four flute
end
mills is such that they don't respond well to rapid feeds, so when you
crowd
them, they tend to drag on the bottom of the primary relief, plus the
chips
tend to overwhelm the flutes.

Have you ever operated a hydraulic duplicating (tracer) mill profiling
aluminum? You can generally plunge diameter depth and run like hell
so
long as you lubricate well and use 2 flute end mills. Makes all the
difference in the world.

Harold


That reminds me of the good old days.... 2 spindle bridgeports... 4
spindle cincinati hydrotails.... 6 spindle wilsons.... tracer lathes...

back when sheep were scared, Jack

Chuckle! Apparently you have!


Hmmm....my stepfather knew Henry Wilson personally....

Lessee....at Certified, we did have at least one 12 spindle hydrotel.....we
had to run 1/2 the cutters as L/H and conventional cut--wasnt worth a damned
for finishing, but for 17-4 and 6al4v it sure shaved off a bunch of time in
the ruffing stages.......

There was also a couple of Wilson's converted planers there that were setup
with ~ 15 ft long tilt tables.....along with the std 3d tracer valve, the
pattern and table would both tilt upon -x- axis travel, via a separate
template attached to the bed....

Wilson's valves would sometimes inexplicably stick and scrap parts, and were
particularilarly subject to problems with fluid temperature...so much that
in the latter days Boing dis-allowed Wilson's valves in their quality
program... no biggee...(LOL) Certified just made up a bunch of data plates
that said "rosebrook" on em and attached em to all the Wilson valves....

Yup, those were the days, all right....

--

SVL