Feed Rates Questions

Good Morning y’all :slight_smile:

So I have been doing some digging and am confused. This is not hard to do at the minute as I am getting into a hobby that requires use of math and stuff I have not used since school.

I am trying to figure out the correct feeds and speeds for a new 1/4in 2 flute upcut bit (Freud 75-102). Freuds website says I should set it between 288 - 396 in per min. I also found a post on here from a couple years ago Here where MalcolmStanley posted his spreadsheet.

This is where I get confused. On page 1 and 2 of Malcolm’s spreadsheet it confirms that 324 in per min would be optimal at 18000 rpm how ever on page 3 (Easel settings) it states for "Hard Maple) 28 in per min would be optimal.

Now with my little machine, would 324 be ridiculous? Am I over thinking things?


Thanks, Drew

So the spreadsheet and the Freud website are interested in the maximum chip load. They want to be able to remove the maximum size of chip that you can and all of that is based on the number of flutes, diameter of the bit, and the RPMs. Chip loading is important to supply cooling to the bit. Unfortunately, the X-Carve will have some serious issues moving at those speeds and it will cause the gantry to deflect. This will lead to poor cuts, broken bits (although you’re probably safe from this with a 1/4" bit), and slipped motors/belts.

You can be a lot more aggressive than the recommended 28 IPM, but it all depends on the depth per pass. For a 1/4" 2 flute upcut you could easily go up to 60 IPM with a 0.2" depth per pass. Run it dry without a board in to see how fast that actually makes the machine go. If you’re comfortable with it, give it a go with some scrap wood to make sure it cuts clean.

Experiment in some scrap wood and see what results you get for various settings.

Good luck!

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Thank you for the info! I still have a lot to learn :grimacing:

Anytime. It’s a lot more satisfying to struggle a little before you get it perfect. It makes it that much better when you do!

Also, the recommended feed rates in Easel are always a safe bet and you can adjust from there.

i use the 75102 almost exclusively. i cut hard maple at 60ipm, with a .08" DOC. it breezes thru.

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