Nomad 3 Z Axis Grinding and Plunge

Hi all -

I’ve been lurking on this forum since before I bought my machine in July and been having a blast since receiving the machine in August. Hopefully I’ll be posting some of my projects after the holiday rush. Mostly topographic modeling, knife handles, cribbage board work, etc.

I have a note out to support but hoping I can get some feedback from the larger quorum to diagnose the problem until support can make it to my ticket.

I’ve had two projects in the last few days that have experienced sudden Z plunge into the material randomly (luckily I’ve been babysitting the machine and can hit the stop button quickly). Most recently, the last project suffered from sudden Z axis stepper “grinding” when trying to raise, only stopping with an immediate power switch hit. After the initial case of grinding, the machine generally suffers the same issue when trying to initialize after powering back on. No issues with X or Y - only Z axis.

I was able to get the machine running the next night (last night) for about ~1hr of cutting only to suffer the same thing making me think it’s static. I pulled the left side panel to check for any obvious wire issues but nothing was obviously out of order. Bummed as I was in the middle of Xmas gifts that likely will not be completed now before the holiday.

Potentially pertinent info:

  • Located in western WA where it recently got colder (+dry air = static?)
  • With the colder weather, I’ve been running a space heater in the garage with me
  • I run a warm up routine pre cutting for ~30 min going through the RPM range
  • Cutting walnut + brass for inlay with intermittent shop vac chip clearing (no issues doing this until now?)
  • Recently put the machine on a rubber flooring mat per guidance on making the machine a bit quieter, but I tested last night without and still encountered this issue.

Guessing static or something similar based on what I’ve seen with the static issues and the Shapeoko’s but any and all suggestions welcome, thanks!


Static issues usually manifest as unexpected disconnects, rather than movement problems.

I would suggest carefully checking all the connectors for the Z axis wiring, and see if there is a loose wire, or if there is any indication of corrosion or arcing on the connector pins, or if the plastic of the connector is discoloured as if overheated (another indication of arcing).


Nomads don’t usually have static issues, and as @mhotchin noted, that’s usually a disconnect.

Do your rails need to be lubricated?

and for the Z-axis linear rails:

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@WillAdams and @mhotchin good to know it’s likely not static. I had only seen a few posts from several years back regarding static and Nomads but I wasn’t quite sure what the cause might be.

I did a light check of the wiring as @mhotchin noted, but didn’t want to dig too deep for fear of voiding warranties and such. If I should open up the board enclosure in back and check connection points I surely can. Just wasn’t sure one best course of action for that since I hadn’t received guidance on my ticket yet.

@WillAdams would doing topography cutting with quite a bit of back and forth in Z exacerbate the need for extra lubrication on the rails? Just asking as the machine is only a few months old and I’ve only done ~5 topographic cuts on it with large amounts of Z travel. If so I’ll adjust my maintenance plan accordingly.

It seems that part of the “grinding” noise is almost as if the stepper does not have adequate power to lift the Z carriage up but this is only intermittent suggesting connection issues? I would think if it were lubrication that problem would be more persistent throughout full Z travel.

@WillAdams just went out to the machine and moved Z by hand a bit. It is definitely much more difficult to move Z up when than when trying to move it down (machine is off/unplugged when manually moving it). Would this be pretty indicative of under lubricated rails?

Yes, sounds like lubrication is in order — please check in w/ if you have any difficulties with this.

@WillAdams that appears to have fixed the issue! Running much smoother now without issue after a several hour cut tonight.

As the Z carriage struggled to raise, the steppers lost steps = plunge into material upon restart. Good to remember!


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