Intermittent extruder loss and stutters. 6HC/toolboard/RRF3.2

dc42

If it's an intermittent issue, then the most likely causes are:

Bad crimp connection in the motor cable. Are you using the same cable as before?
Bad solder joint between the driver chip and the PCB. Axz the pads of the driver under underneath the chip, it's impossible to tell whether the soldering is good on all pads other than by X-ray; although if you can look at the edges of the chip using microscope, you might get a clue.
Bad solder joint between the motor connector and the PCB. Unlikely, but not impossible.

hamel

@dc42 Thank you for the reply.

Just to recap, as I know I have been changing things around a bunch...and my symptoms changed for a bit due to the bad motor giving me a runaround:

New cable. Known good crimps. Known good pinout/coil pairs. New motor that is much larger running at 80% rated current (rated at 1.2A). Soldering on the board in general looks OK, slightly blobby, but nothing that looks like it would make me questions the soldering on the chip. Solder joints to the connector looks fine as well. Wire wiggles do not affect anything, and no driver faults reported.

When printing, it skips steps like it has a loss of torque. I can hear and see the motor try to move, but even with the motor off the extruder and no load, it skips when printing. If I pause the printer, it will extrude with DWC just fine. I can really crank the rate, and I can grab the motor gear and it will just rip past my hands. While printing and motor with no load on it, it has no torque and I can stall it easily with barely touching it, and it often skips steps with no load on the motor.

The weird intermittent side of things is that I can print, reboot, print, reboot, print, and after a totally random number of reboots and prints, it will extrude with full torque. The extruder working is definitely the exception, as it is almost always not working while printing. When it does work while printing, it only stops working again if I cancel the print and restart.

This really does not feel like wiring to me, but since I am at a loss here, I have checked it all over with back probes. All have good connections. I am at a total loss, and I am totally up for reworking all of the diagnosis that has been done, but I do not know what general area I should be going over again. Thoughts @dc42 ? Again, thank you for the help.

This is frustrating, as everything looks correct to the best of my (little) knowledge with RRF3. I am a research engineer, and can work any angle you think needs to be worked. I do have an x-ray in my building, and if you really think it is necessary, I can have someone scan it. I am hesitant, as the "intermittent"ness of this doesn't cry connection to me, but sounds more like the driver is not sending full power when reading the gcode. But I am at a loss right now, and other than removing the toolboard and going to an expansion, I am not sure what the next steps should be.

I have an 8 tool custom printer running toolboards and duet3, and it gave me no issues at all (sans the fun firmware learning curve). I am not sure how I am unable to get this simple Voron printer running with a toolboard and duet3.

jay_s_uk

@hamel sounds a lot like this thread
https://forum.duet3d.com/topic/21922/expansion-3hc-m906-not-working-properly

hamel

@jay_s_uk Thank you for that. It does seem similar. I do have a G4 S1 to wait for boards to boot, but I will give it a try with an S5.

hamel

@jay_s_uk No change. Still extrudes fine with DWC, but when I go to print, it has no torque and just skips. When the motor is loose, same issue with no torque when printing from gcode.

hamel

Just as an additional note, the driver on the LC1 is loud as well. It is in idle hold now, and is singing like it was trying to hold position with great strain, but it is loose and not loaded.

hamel

https://photos.app.goo.gl/6BLAn9YM2FAjzoWh6

Phaedrux

Very strange. Can you post your start gcode and pause and resume files?

hamel

@Phaedrux Yes, this is a first for me, and I use Duet for most things here, not just FFF printers. This was just a "let's build a printer with the spares that we have", and we chose Voron. Seems like this should be quite simple to get running, but this issue has been plaguing me for almost a month since the machine was built and wired. I don't know what else to try.

Start:
T0
G28

Pause:
M83 ; relative extruder moves
G1 E-2 F3600 ; retract 2mm of filament
G91 ; relative positioning
G1 Z20 F360 ; lift Z by 20mm
G90 ; absolute positioning
G1 X0 Y0 F6000 ; go to X=0 Y=0

Resume:
G1 R1 X0 Y0 Z5 F6000 ; go to 5mm above position of the last print move
G1 R1 X0 Y0 ; go back to the last print move
M83 ; relative extruder moves
G1 E2 F3600 ; extrude 2mm of filament

Phaedrux

Can you post your gcode file you are trying to print? Is there perhaps a difference in extrusion rate between the manual extrude and the print extrude commands? Maybe the print is trying to push too much filament and it simply can't?

hamel

@Phaedrux Gcode is in the first post. I have changed a few settings in the slicer, but nothing big. I've turned off retracts etc. to reduce the variables, but it really just seems that I get very low torque when printing. Maybe it has something to do with microstepping? I have tried setting the extruder to all of the microsteps, but there was no real change on either. Doesn't look like the gcode is changing the extrusion rates to anything large, they are all very small values. I can manually extrude with all of the presets except for the 60mm/s one, as that will overrun my melt rate pretty quick.

Phaedrux

Let's replace the board. Please contact your vendor and initiate a warranty exchange. Include a link to this thread as authorization.

hamel

@Phaedrux Thank you. Just to clarify, as I Filastruder is asking, which board are you recommending replacing, just the LC1, correct?

dc42

@hamel said in Intermittent extruder loss and stutters. 6HC/toolboard/RRF3.2:

@Phaedrux Thank you. Just to clarify, as I Filastruder is asking, which board are you recommending replacing, just the LC1, correct?

Yes, just the 1LC.

hamel

@dc42 Thank you.

hamel

@dc42 I just installed a new toolboard with updated firmware. I have the exact same symptoms, which are:

Extrudes fine with DWC
Extruder drive just jitters and does not turn when printing gcode
If I pause, I am able to extrude just fine, but again fails to extrude when resumed
I am using the same firmware, config.g, and gcode as posted before
I have put a DMM on all connections, and they pass the wiggle test
I have tried in SBC and standalone. I am back to SBC now.

Has tons of torque when commanding from DWC, but no torque when printing (I have tried a free motor with no load, and it will not even turn when printing). I do not see any gcode issue, and I think my config.g is set up correctly (could you please double check it?). My drive settings are similar to what others are using on the same extruder.

hamel

Any idea as to what my next step in troubleshooting this would be? I have played with config.g drive settings some more, but nothing seems to change the behavior.

Phaedrux

sorry about that delay.

Can you confirm that the newly received tool board has been updated with matching firmware for the main board?

hamel

No worries. I know it only takes a day to have tons of new posts to look through.

Yes, I can confirm that they are both running 3.3 beta2.

m115 b121
Duet TOOL1LC firmware version 3.3beta2 (2021-03-10 10:06:22)

m115
FIRMWARE_NAME: RepRapFirmware for Duet 3 MB6HC FIRMWARE_VERSION: 3.3beta2 ELECTRONICS: Duet 3 MB6HC v0.6 or 1.0 FIRMWARE_DATE: 2021-03-10 13:39:39

Phaedrux

Thanks. Hopefully DC42 will have some time to take a look soon.