Speed For Milling On A Lathe

The plan is coming together:
Use MT3 Sheldon holder with set screw.
Speed 900 rpm
DOC .080 '' (mikey was the .80 you mentioned above a typo?)
Squirt tapping fluid on cut
Power feed with cross slide at rate of ?? (need help on this)

Feed by hand till you know what speed is ideal, than match that speed using power feeds.
 
The plan is coming together:
Use MT3 Sheldon holder with set screw.
Speed 900 rpm
DOC .080 '' (mikey was the .80 you mentioned above a typo?)
Squirt tapping fluid on cut
Power feed with cross slide at rate of ?? (need help on this)

Hi Toz,
power feed is normally calculated on mills as chip load x number of flutes x cutter RPM and in inches/min, as you're using a lathe it's slightly different, but no more complicated:

with a chip load of 0.003" per tooth, 4 flutes, you'll want 0.003" x 4 per revolution, so 0.012" - this is a ball park figure, chip load could be anywhere between 0.002" and 0.006" for HSS cutters in "medium" steels.

Remember, too little chip load and the cutter rubs and "burns up" (the material can work-harden too), too much and the cutter breaks :)

Dave H. (the other one)
 
Excellent, thanks so much folks. Now just have to wait for holder and end mills to arrive in the mail.
Will let you all know how it works out.
Mike
 
Just in case the mystery metal sends it's hand basket to a truly hot place, ruining your end mill in the process, I have salvaged projects like this by cleaning up the drainage ditch sides with a small carbide rotary file so that it looked like a keyway should.
 
Alrightie then, the job went great as planned. I ran the feed at .002" and got good chips with just a bit of smoking from the lube.IMG_1481.JPG
It was a big boost to my confidence to have your help. Thanks a heap. Machining is FUN!
 
Interesting work holding set up. I'm surprised it held but glad it worked out.
 
The work holding set up is very solid. It took a bit of careful grinding and filing to get a good fit of the bent tail in the tool holder. It also took some grinding to get full width contact of the work in the dog.
Even so I wasn't expecting it to work out as well as it did.
 
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