Z Axis reversing - not the first run after assembly

Bottom Line UP Front: Z-Axis is randomly going opposite direction during jogging. Jugetek Motor (different from X/Y motors)

Assembled and tested Pro XXL over the past few days. Using caution because I am a zero hour newbie. I did some dry runs and then ran with the sharpie and a simple text file (similar to Hello World). Then I went with the MC Etcher and was successful on a test and small aluminum plate.

Today, first initialization and I got the Homing Fail error. Checked as much as I could and read what I could find. Notable here: Z Axis was noisy.

Now, ran some jobs on pine with the spindle going. No problems (other than my learning curve). Performance was flawless. Attempted to jog and stepper is making clunk sound and randomly going opposite direction. When commanded up, sometimes up, sometimes down…and vice versa. I don’t even know where to start beyond searching here. Since it has been working with fine tolerances and this is not the initial start-up…I am lost.

BTW - Super stoked that this is here, assembled, making chips, and it has far exceeded my expectations in design and accuracy. I took a few build notes that I’ll put up later.

Blue skies,

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Check all connections on the Z motor from the motor to the board. Sounds like a wiring issue.


Define “noisy” - as in crunchy sort of physical noise, or doesn’t move smoothly, or the pitch of what you hear changes?

If you can’t home, there’s almost nothing going on crosstalk/spindle wise, that’s your first big indicator. It’s a wiring issue with either the switches or the stepper, most likely the stepper, but check the switch just to be sure it’s tripped before htting the mechanical limit, etc. Check theindividual pins on each connector are mating solidly.

This actually sounds like a ringing issue on the coidl driver lines, the fix for which is good connections and potentially extending the pulse length in GRBL settings, but best to leave that alone for now.

checked both end of the connection…

Have you contacted support yet ? (support@carbide3d.com)

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I wonder if the failed homing cycle has left the machine in an uncertain co-ordinate state, and something counter is topping out - hence the apparent flipping of direction. If it sometimes goes the right direction and others not, it means it ‘can work’. So my gut feel says: a) homing cycle failure related, b) wires touching intermittently in a connector…
Support, by the comments seen on this forum, are very good at finding and sorting these sorts of issues

I have not contacted support yet. I was hoping to find an answer (searches), or crowdsource it (here) before I sent it to them. I won’t hesitate to go that route, but I am trying to respect that inbox.

It’s much better for us if you contact support@carbide3d.com — please do for any issue with the machine.

“Noisy” to me at this point means crunchy stepper sound, rather than sand in a gearbox. The movement is jerky at the same time. It is not a pitch problem (as in a speed change from high to low pitch or similar). It seems that part of this is the reversing issue. It is possible the “noise” I am hearing is a connection that is intermittent and the stepper is repeatedly clunking to find its position - and without knowing it’s position - is slow to move? Still searching.

Homes ok, switches ok, pins all straight inside connectors, connectors mated flush/full depth.

I’ll standby on pulse length and ringing! :slight_smile:

Ok Will, I am on it.

I am up early running some tests to gather repeatable data and form a coherent question.

Thanks AndyC,

I have made a mental note of your thoughts. Seems plausible. It homes ok now, so that error may have been user-induced. Wires touching is what I have been sniffing out, slowly. Nothing yet.

Bot says reply to everyone individually in one response. Wilco, good bot.