Steel Milling baseline settings/suggestions? Dewalt DW618

I plan on cutting 24" x 24" x 3/8" steel, around 60.5lbs. My CNC has a bed of ~35" x 35" x 6", but the steel has been raised to make the Z axis shorter.
Here’s my current settings, but I haven’t run it yet; Just wanted to check up on the forums to see if there are suggestions.

The endmill I’m using is;
“Square End Mill: 1/4″ Dia, 4 Flutes, 3/4″ LOC, Solid Carbide, 40 ° Helix”
and my Router is a Dewalt DW618, RPM settings ranging from 8,000 to 30,000 I believe.


Any suggestions is greatly appreciated !
Thank you.

Even though you use trochoidal, 1mm seems like a lot. :smiley: But that’s just a gut feeling. Just try. :stuck_out_tongue:

1 Like

Man, that’s going to be loud!

your plunge speed z axis looks to fast would take something like 0.8 or lower …, 40% could be smaller loos the up down z axis… the 1.400% could be something like 10% maby whit over cut en the second time (passe) the normal precision cut

I use 7% for aluminium 10mm deep. I would not go higher, that’s the value, together with DOC, that is going to strain the endmill the most. Rather start slow and nibble away at it. Heat should not be a problem with trochoidal.

Hello and thank you for the replies.
I did attempt with the settings, but need to go back to the drawing board as the Z axis is not perfectly ridged (the core slightly shifted while printing)
Are there recommended RPMs and endmills? Also, is there anything that should be added to the MPCNC in order to better sustain cutting steel? I’'d like this to be as beefy as possible, as I need it to fabricate many pieces for project cars of mine.
Thank you very much.

1 Like

You are using a large diameter endmill with a lot of flutes. It is going to be hard to get your router to run slow enough.

It would be better if you got a 1-2 flute. I think that would be an easier starting point…but it is steel your settings need to be perfect. Have you milled plastic or aluminum yet? Those skills will transfer to your steel attempts.