On Sat, 16 Jan 2016 14:22:09 -0500, wrote:

On Sat, 16 Jan 2016 13:37:21 -0500, "Jim Wilkins"
wrote:

wrote in message
. ..
I've got a little job I need to do/get done. I am working on the
wing
strut fittings for the bush-plane. There are 4 struts - so 8 strut
end
fittings. They are made of 1X1 6061T6 - 4 abot 4 1/4 inches long,
and
4 about 5 1/2 inches long.
2 need 1/4 inch slots, 4 need .195" slots, and 2 need 3/16 " slots -
all 1 3/8" deep.

I may have the use of a bridgeport style mill that used 3/8" shank
cutters, and I have located a 3/16" end mill that has 5/8" cutting
depth (end mill)

How close to 3/16 will I likely be able to get? (thinking the cutter
is going to want to "walk" a bit in the cut) Would it help a lot if
I
drilled a row of 1/8" or 5/32 holes down the center of the slot
first
to reduce the chip load????

Or do I just farm it out to a CNC shop??

If I had access to a horizontal mill it would make life a lot
easier,
but nobody has them any more.

http://www.mscdirect.com/browse/tn/T...navid=12108552


The cutter would have to be at leadt 2 3/4" plus the diameter of the
arbor to do the job. Unlike an end mill, you can't cut to a straight
end cutting through the 1 inch dimension, and you can't flip it over
to cut from the other end.

I thought about trying to jig the parts up to slit the ends with the
14 inch cutoff saw (abrasive wheel) but the thought of loading the
wheel with aluminum changed my mind on that pretty quick - not to
mention the flexability of the fiber abrasive wheel..

A "cold cut" saw would work - it turns a bit slower than the average
table saw, and the blade is made for cutting metal - but I don't have
one and the quality of the finish of the cut would likely leave
something to be desired.

Cold saws are cutoff saws. With a few exceptions (Amada makes one
such) they don't leave a great finish.

What you want, I think, is someone equipped with a horizontal mill who
does a lot of slotting work. As for the geometry, shank-type cutters
for a vertical mill can cut slots, but I've never seen one that could
handle that depth. Arbor-type slotting mills are the tools that would
give you the accuracy and finish you're talking about, and they're
mostly horizontal-mill tools. They come in a wide range of diameters.

I'm speaking not as one who has done it, but who has seen thousands of
milling cutters and tool setups -- run by other people. d8-)

--
Ed Huntress