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Mechanical Magic Mechanical Magic is offline
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Default 1/8" end mill speed and feed

Speed for mild steel no faster than 120 ft/min, but since you will
probably be using a squirt of cutting oil, maybe 60 ft/min. A 1/8"
endmill is .033 of a foot in circumfrance. 60/.033 = ~1800 RPM.

DOC 1/4 of diam = .032"

Feed .0005" per tooth, two flute cutter = .001"/rev. At 1800 rpm =
1.5" per minute, that works out to one turn every eight seconds.

When I hand feed, I use a two handed motion, (grabbing on the dial),
one hand rotates about 20 degrees, then other hand 20 degrees,
repeat. By making the changes often, it seems to even out the motion
for me Easier if you have round wheels instead of a crank.

That's where I would expect to run.
Dave

On Feb 16, 7:58 pm, GeoLane at PTD dot NET GeoLane at PTD dot NET
wrote:
What depth of cut is safe to take with a HSS end mill of 1/8" dia, and
how fast can you feed in mild stee without breaking or quickly dulling
the end milll? The ROT of that I'd read in a book years ago was 1/8th
of the end mill diameter as the depth of cut (0.015 for an 1/8" mill)

I don't have power feed, and have never had coolant, except flood
coolant (what a mess) the few times I ran the horizontal part of the
mill. [1940s vintage Hardinge Universal horizontal mill with a
Bridgeport C head in the overarm hole for vertical milling - not very
rigid, but it's what I have] Any technique to use to do hand feeding
of the table?

Thanks

RWL