I just got back into using my MPCNC machine again after rebuilding the centre gantry - I found it wasn’t very square for some reason the combination of parts from my old and new 3D printer weren’t very square.
Since I built it I was having heaps of trouble with the X/Y axis skipping and generating lots of vibration. The endmill was chattering, resonance through the whole thing. The frame brackets were cracking all a bit of a mess.
I cut down the Z axis as I thought that was two high. Adjusted the driver voltage, started playing with the microstepping jumpers. I’d originally bought the most powerful NEMA17 steppers I could source. (59Ncm)
Nothing really helped, so I figured that was just the way it is, and ran the machine very slowly with a shallow cut depth and it was mostly okay.
I came back to the forum here and started doing some reading again and came across the bit about wiring the steppers in Series. So I did that and now my machine is a completely different beast. (Since then I’ve seen the dual drivers / auto-squaring - I’ll leave that for another day)
I think the graphs on this site sum it up. Double the torque at slow speed in Series.
I got a massive improvement and I can now run at the recommended feedrate, no skipping, good accuracy, resonance gone and no problems with the cut depth. I can’t really understate how much of a difference this made for anyone having similar issues.