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MakerMade M2 Z axis Machine Position drifting

Hello all. I am having an issue with my Z-axis that has me stumped and I am hoping to tap into the community wisdom.

Main particulars:

The machine is a MakerMade M2 from 2020, running MaslowDue v20200915 firmware.
Currently running Makerverse v1.1.3 #304 on Windows
G-code for these particular cuts have been output by Inventables Easel.

If my memory serves, I’ve had the M2 running since about September 2020 and it has worked very well. I’ve run it enough to have gone through sets of brushes on the routers, and have had very little trouble and generally excellent results with it.

The problem now is that the Z-axis Machine Position is drifting relative to reality during cuts. It started just last week while working on a sign using a ¼” 60deg v-bit. I noticed small details across a long cut sequence that were supposed to be the same size were getting deeper and thus wider as a cut proceeded until the bit was just burying itself in the project that had a maximum programmed cut depth of 4mm.

Troubleshooting steps I’ve taken:

  1. Mechanical Checks
    -Marked and measured the bit to make sure it is not migrating
    -Marked and measured router barrel in bracket to verify constant position
    -Marked linear drive screw to gear to verify not slipping, checked set screws are tight
    -Checked Z motor gear set screws are tight. Also checked for signs of slipping on shaft.
    -Belt is tight
    -Checked Z cable fully seating at motor and Arduino
    -Discovered Due board was not fully seated - corrected with no improvement
    -Checked gantry and car for anything loose, including security to sled

2)Software - I was using older Makerverse (v1.1.2?). Updated to Makerverse v1.1.3 #304

Tracked data of the drift:
I started tracking the Z Machine Position (MP), Work Position (WP) and Actual Measured Position (AMP) during a series of test cuts today. The measurement for the Actual Measured Position was taken between the top of the z-axis car that the router is mounted on and the left side bracket that holds the smooth linear guide rod using a machinist ruler. It is just an easy spot to measure accurately. Each time I checked the position marks listed above to rule out other wandering components.

Essentially, I would set Z Work Position, run a toolpath sequence, and see how far it had drifted, then reset the Work Position and repeat.

Cut 1 (40 minutes)
Before: WP 0.0 AMP -33.5mm MP -12.4mm
After: WP 0.0 AMP -34.0mm MP -12.4mm
Drift: -0.5mm

Corrected by moving Z +0.5mm and resetting WP

Cut 2 (1 hour 20 minutes)
Before: WP 0.0 AMP -33.5mm MP -11.9mm
After: WP 0.0 AMP -35.0mm MP -11.9mm
Drift: -1.5mm

Corrected by moving Z +1.5mm and resetting WP

Cut 3 (1 hour 35 minutes)
Before: WP 0.0 AMP -33.5mm MP -10.4mm
After: WP 0.0 AMP -34.5mm MP -10.4mm
Drift: -1.0mm

Corrected by moving Z +1.0mm and resetting WP

Cut 4 (1 hour 35 minutes)
Before: WP 0.0 AMP -33.5mm MP -9.4mm
After: WP 0.0 AMP -36.5mm MP -9.4mm
Drift: -3.0mm

Corrected by moving Z +3.0mm and resetting WP

As you can see, the actual measured position is changing relative to where the machine thinks it is. Setting the work position each time just gives a starting point for each cut but you can see the Machine Position tracking the cumulative drift of all the cuts. Interestingly it is always in the same -Z direction, never +, but the amount is not necessarily consistent with cut time.

I cannot find a mechanical cause, even when watching closely for entire cuts. I can see the cuts getting deeper but I can’t see the action of the change. That leads me to suspect it may be electrical or software.

I did see on here someone mention power cord interference with the Z-motor cable and thus separated them with no apparent change.

The cuts I’ve been trying to complete are moderately detailed and involve the Z position moving frequently. The z drift is just obliterating any detail. Definitely not a typical plunge with a long perimeter at depth save for a few tabs type cut.

Anywho… Tips would be appreciated.

1 Like

First of all, awesome post. It sounds like you have already done a very through investigation of what is going on.

There is a way that we can confirm this. Forgive me if you already did this and I misunderstood. If you mark the output shaft of the motor does it end up at the same place when you go back to zero? If it says the position is 0.0 and you can see that the shaft has moved then it could be electrical or software.