# Thread: Feeds IPM and IPR

1. ## Feeds IPM and IPR

First off I am New to the site and love it and also am new to the Career as an operator and trying to figure out how everything works together. Had a couple questions im sure someone can help me with. How do i get my feed rate in IPM for the mill? and IPR feed for turning on the lathe? I have figured out how to get the RPM for both by sfpm x3.82/Dia. and sfpm =RPM x DIA. /3.82 but were do i get the IPR to find IPM and chip load does this come from a tooling catalog?

2. Maybe I was wrong. No reply. Did I post this in the wrong section or is it a stupid question ?

Since you know how to find sfm and rpm from each other this is a breeze.

Chipload is based on the amount of material each cutting flute will remove per rotation.

So when you have calculated your rpm you can calculate your ipm based on what you want your chipload to be per teeth

Ipm = rpm * chipload * number-of-teeth

So you have a 4 flute endmill doing 2000 rpm, and you want a chipload of .001 per tooth:
2000*4*.001 = 8ipm

Now I'm sure you can rearrange this equation as you see fit to find any of the unknowns based on your knowns

Now say for some reason you have to command in ipr

Ipr = ipm/rpm

So 8/2000 = .004 which makes sense since we want the chipload to be .001, 4 teeth doing one rotation over a span of .004 equals .001 per tooth

Bingo!

4. Thanks that makes the picture a whole lot clearer for me