Z axis issues, one motor gets stuck

Got the maslow mostly up and running, I’ve been able to make some cuts (as long as I don’t use the vacuum hose, I suppose because of the static.). My issue is towards the end of cuts I’m using Kiri:moto to add tabs and when maslow gets to that part of the program where it starts cutting the tabs, it has to translate all the way up in Z, move over, and jog back down to resume cutting. Most of the time when jogging back down, the Z stepper motor closest to the vacuum port gets stuck and maslow gets canted as the other Z stepper continues to turn.

It’s consistently on the same side. Any ideas? This has happened on probably 80% of my cuts.

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double check that both stepper motors are solidly plugged in, but if so, it may
be that you have a bad board.

I think one person had a heatsink that was hitting some pins at some points, so
you may want to check that, otherwise contact @Anna or @bar to talk about
getting a replecement.

David Lang

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I’m a little surprised it raises so high for tabs. When I insert tabs using MakerCAM I don’t think the bit rises more than 1/8" above the surface. While it would be good to do the checks per @dlang above, you might want to check the settings in Kiri:moto to see if you can reduce that.

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I didn’t notice anything about how high it’s going. Are you going high enough
that it’s coming off the top of the lead screws? that could cause this problem.
You only have a little over 2 inches of travel from the router being all teh way
down against the frame.

David Lang

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No, it’s not coming off the lead screws, just high enough to clear the workpiece. I realize it doesn’t need to, though. I will dog into the Kiri:moto settings and see if I can keep the bit lower.

I’ve had it get stuck just jogging around the board though, it’s not only when I run a program.

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I’ve seen someone on this forum with an issue with a stepper, where the nut had a lot of resistance, which caused the stepper to skip steps. I don’t remember if it was the nut or the acme thread that was at fault. You could check if there is an issue.

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You can also mess with the z-axis feed rate. Stepper motors have more torque at lower speed so if it’s trying to move really fast it might have less power.

Thanks. I went out last night and turned both by hand, and there is a part of the travel on the motor in question where it’s definitely harder to turn than the other motor or than the rest of the length of travel. Can’t say it binds, necessarily b/c i could turn it by hand, but it definitely took more torque. I can try lowering the Z feed rate and see if that gets it through. I also ordered another stepper motor so I can try that once it gets here and see if it was the screw thread itself.

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So I replaced the one stepper motor, and now that part seems to be working better but I’m running into other issues. I’m wondering if it a bad PCB? After I replaced the stepper, jogging the machine was very odd, it would almost wobble, including on Z translation with the belts hooked up.

I tried the latest firmware and re-running the calibration, trying to start over from scratch. Calibration said it was complete, but when I tried jogging the Maslow, it was still moving oddly.

Now I can’t even connect to WiFi anymore. @bar @anna @dlang , any ideas on what I should do next? I’ve probably put 60+ hours into this thing and I have 2 successful cuts to show for it, both of which came in the first week I got it put together.

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Do you have a video of this? I’m having a hard time picturing what is going on

Sorry for the delay in replying, we left town for almost 2 weeks. With a clear head, I flashed the latest firmware, re-ran calibration, and was able to get a good cut yesterday. The nut for the stepper motor was definitely causing my z-axis issues. I tried it on both the new and old spindle, and it binds on both. The new one that came with the new spindle is smooth and everything seems to be working as it should.

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