On 4/13/2015 11:04 AM, Leon wrote:
On 4/13/2015 9:48 AM, Greg Guarino wrote:
On 4/13/2015 8:43 AM, Swingman wrote:
On 4/13/2015 6:11 AM, Greg Guarino wrote:

But I read things that confuse me about the ends of these bits;
specifically that they are not designed to cut "forward", only
sideways.
Some of those accounts say they cut "forward" OK in wood, just not in
the metal they were designed for.

Did the bit you got have a different sort of end? Or does the relative
ease of cutting wood render the subject moot?

One more thing: The 3/8" adapter you used worked well? Is it just a
split tube or something like that? No worries about a secure grip on an
object spinning so fast?

OK, one more, more thing. I have done the very tiniest bit of metal
milling in the distant past. In those applications (aluminum) the speed
was lower. What speed did you use for wood routing?

Been using these extra long end mills from Travers Tools for routing
mortises over ten years.

The price will scare you, but you get what you pay for. I have cut
literally thousands of mortises with these, haven't had to buy but once,
and use them on both my Multi-Router, and plunge routers, at high speed,
and with Porter Cable collets:

https://picasaweb.google.com/1113554...8 20426286658




Photo is so you can get the part numbers, otherwise it would take a
while to find the correct ones.

http://www.travers.com/342075-20-501...rch=20-501-170

I see that those are center-cutting. I'm trying to determine if that's
necessary for wood use. And the price for 1/2" is pretty eye-popping. Do
you use an adapter for the 3/8" shank, or have you got a 3/8" chuck?

FWIW "I don't think" normal straight cut bits are centering... I'm not
so sure how important that is, if I have an understanding of the
centering function. Maybe center cut means you can cut with the side of
the bit vs. just the tip.

Also the bit on the second link above is carbide. Mine is HSS and has
held up far better than any carbide bit I have had and it has only been
used on Ipe. Ipe is about 2.5 times harder than oak.



Here's what I found, which seems to mirror my (slight) understanding of it:

"An end mills end cut type is either center cutting or non-center
cutting. Center-cutting end mills can create three-dimensional shapes
and profiles, and make plunge cuts similar to a drill bit.
Non-center-cutting end mills are suitable for peripheral milling and
finishing, but cannot make plunge cuts."

In other words, "non-center-cutting" can cut by plunging into the
material, like a drill bit. It can also cut by moving the bit from side
to side. "Non-center-cutting" is intended to cut ONLY on the sides, with
"X-Y" motions, no up and down plunging. At least that's the case for metal.