MPCNC Primo - Z axis lifting during milling

Hey guys i’ve almost got my Primo working. I just did my first 3d Fusion360 program and im finding i have an issue when milling out in a circle the z axis seems to lift and resets its 0 point.

This is what im meaning


This is what it produced

Almost seems that its only getting effected during the spiral movement.
Heres my Gcode.
ArduinoCaseBottom.gcode (437.5 KB)

My Setup:
MPCNC Primo
Ender 3 pro mainboard running custom Marlin, no endstops.
Fusion 360 processor: Setting up Fusion 360

That’s weird. I’ve never seen one push the Z up before. Also doesn’t look like you’re using the fusion to marlin post processor. What happens if you try to cut the depth per pass to say, half the depth? So instead of hogging out everything in one pass, you do it in two.

If it’s the wrong pp, or even with the new nerfed fusion cam, I would suspect high Z speeds to cause skipping steps.

You can force a max speed for Z with M203:

M203 Z4.0

That will limit the Z to 4mm/s.

1 Like

Ah cool thanks for the replies. Any ideas on which PP I should be using?
Ill try running it with multiply passes if I get a chance tonight.

I’m tempted to run the program again just to see if I get exactly the same result. As I do wonder if it was my tool sliding up into my spindle which could have caused it, if the rotation of the tool vs rotation of the spiral was making it go up. Since I have to run a collet adapter in my machine it could possibly cause an issue.

I’m quite new the the fusion360 cam setup have only used it for modeling and exporting stls in the past :-).

The guffy post processor is the most common. But fusion free plans recently took away some of the speed changes possible. So it may still be broken.

Ah makes sense. Yea I am using the guffy one.