Motor phase error as Y or X motor; works as Extruder motor

jrwaters2

Hi

I have a Duet 2 Wifi. My system has been working great for a couple of years. I decided to give a through cleaning including linear rails, etc. so I dis-assembled much of the system. I only unplugged 1 of my motors - for my Y axis.

When I put everything back together, homing Y gave me an error message (similar to below or exact - issues with phases). I get this error consistently now:

G28 Y
Warning: motor phase A may be disconnected reported by driver(s) 2
Warning: motor phase B may be disconnected reported by driver(s) 2

I decided to re-wire the connector. One of the connectors seemed damaged to me and I was easily able to snap that crimped connector off. I re-wired all 4 wires of the connector, checking under microscope. Everything looked great. But still does same thing.

So I checked that motor on X axis and got same issue. However plugging it into extruder it works fine. At this point I don't think any motor will work attached to X or Y.

All of my fuses look good from visual inspection. I'd appreciate any ideas on what to try.

Thank you
Jack

jumpedwithbothfeet

@jrwaters2 did you clean the board at all?, re-check the wiring, re-check the connectors, check the board socket is clear, check the back of the board as well as the front is clear from any debris disturbed whilst cleaning.

Another thing I've had in the past is when pushing the stepper plug into the board one of the pins actually got pushed out of the way causing a bad connection but looked fine and tested fine when disconnected.

jrwaters2

Hi @jumpedwithbothfeet

I didn't touch the board during the cleaning process. Only after the problem was fully manifested did I unplug everything from the board and unmount it so that I could do visual inspection. Things I looked at

Fuses
That the pins on the back of the motor connectors looked clean, nothing loose, no obvious missing solder

I have just now checked the pins themselves that slide into the connectors and none of them are bent or look damaged in any way.

I was wondering if, when that X-MOT connector was weak, if the board could have been damaged in some way due to this. Its odd to me that the motor works fine for extruder but not X and Y.

I believe I tried the extruder motor on the X-MOT connector and that it gave the same result. I'll confirm that later this morning.

Thank you!
Jack

jrwaters2

I just tried my extruder motor in the Y-MOT and get the same error

4/17/2022, 10:24:16 AM G28 Y
Warning: motor phase A may be disconnected reported by driver(s) 2
Warning: motor phase B may be disconnected reported by driver(s) 2

BUT THEN, this is where it gets really strange. I powered everything off and plugged both that motor and one other into the Z-MOT connectors and everything worked fine. I didn't expect this. I kind of though X,Y, and Z were all not working but that the extruder motors were (I thought this because of something I saw before I got careful about characterization).

So then I tried the X MOT and it worked.

So then I tried the Y MOT and it worked.

EVERYTHING is working now. This is not very satisfying because I can't reproduce the issue but something was definitely wrong.

I'd love to pursue this if you have any ideas.

Best
Jack

Phaedrux

@jrwaters2 said in Motor phase error as Y or X motor; works as Extruder motor:

I'd love to pursue this if you have any ideas.

I would say it sounds like either an intermittent break in the wiring or bad crimp connection.

jrwaters2

@phaedrux, I really appreciate your insight.

Its a painful conclusion for me. I'm "that guy" who needed extra crimps because I find the crimping so difficult. I'm great with software, clumsy with hardware. But I thought I had turned the corner after so much practice.

At this point I'm going to assume - and probably should have from the start - that it was poor crimping (though I swear putting it on extruder seemed to work 100%) and . . if I can get it to happen again I'll re-crimp and take pictures and keep this group posted.

You all are awesome - thank you again!
Jack

fcwilt

@jrwaters2

When it comes to crimping the right tool can make a world of difference.

The manufacturer of crimp connectors will specify the recommended tool for each one of their products.

But those tools tend to be more expensive then the general purpose tools that many folks favor.

What tool are you using?

Frederick

jrwaters2

@fcwilt Hi - sorry I'm just seeing this. Busy times and I had a bit of travel come up to India and Spain that got extended further than I wanted.

I'm using an IWISS SN-28B Dupont Crimping Tool for 3.96mm, 2.54mm, 2.5mm Pitch Dupont, JST XH VH Connectors, AWG 18 to 28.

I just had the problem happen again today which is what triggered me to give you all an update and saw this. Based upon the comment by @Phaedrux that it sounded like an intermittent break or wiring, I decided to

Make sure the end at the motor was tight
Re-crimp the ends and take a picture to post in case there is something obvious. After taking the picture I did clean that black one up a bit. Can't believe I didn't re-take picture
Substantially shorten the cable as it was far longer than it needed to be

After these steps, all is fine again. I suppose I'll monitor it but definitely appreciate a) any thoughts on the tool or b) any input on the crimps

jrwaters2

I finally have some closure on this topic. Until recently, the motor in question has been working just fine. So I assumed it was some form of user error.

Recently that same motor stumbled. Upon inspection, I found that the motor would work fine but if I touched the wires near the entry to the motor, it would stumble.

Unfortunately the leads are hard-wired into the motor so this is not something I could repair without dis-assembling the motor.

The good news is that I finally have resolution and this one was not my fault. All of that practice crimping made the replacement with the new motor uneventful.