[Unabiker]

Well that makes a lot more sense. So when you are using a 2 flute cutter, multiply your desired chip load by 2 to get your IPM.
I find that when I am drilling, or even plunging straight through, I will get a slight burr unless I am using a new (sharp) bit.

[dlange]

Ok this doesn't make any sense whatsoever


First of all 2716 RPM?? Isn't that way too slow?
IPM 9.114?
IPR .0034??

Now my machine's operating speed is in IPR.
The last guy who figured out these speeds and feeds was cutting through 6160 not as thick as .375" like I'm attempting, but was cutting through .275" and had a mirror shine, single flute @ 15K RPMs with .133 Feed or IPR

To get any of these feeds to make sense I usually have to put in an IPM of 750 or higher in the calculator, just so that the IPR starts making sense.

I'm using HSS 12mm Single flute helical cutter. Conventional and climb cutting. The best I can do so far is 14K RPMs with a .2 IPR Feed
I get a nice sounding cut but the bottom part of the circle looks rough, and the top part of the circle is shiny.