Extruder motor not running during print job but working after I preheat the extruder and test it

4

I have a Prusa i3 (from FLSun). I have assembled the printer, calibrated it (fairly decently), and have successfully demonstrated extrusion manually. However, when I try to run a print job (the G-code clearly contains E commands), the extruder motor never rotates. Is this a common problem? Any suggestsions for how to resolve/troubleshoot?

I can confirm that the extruder was pre-heated for PLA (up to a generous 220 C).

I load an STL file into Repetier v.1.0.2, use the built-in slicer (Slic3r) to generate the G-code. I include a sample of that below:

; generated by Slic3r 1.2.9 on 2017-11-08 at 10:54:07

; external perimeters extrusion width = 0.50mm
; perimeters extrusion width = 0.72mm
; infill extrusion width = 0.72mm
; solid infill extrusion width = 0.72mm
; top infill extrusion width = 0.72mm

M107
M104 S200 ; set temperature
G28 ; home all axes
G1 Z5 F5000 ; lift nozzle

M109 S200 ; wait for temperature to be reached
G21 ; set units to millimeters
G90 ; use absolute coordinates
M82 ; use absolute distances for extrusion
G92 E0
G1 Z0.350 F7800.000
G1 E-2.00000 F2400.00000
G92 E0
G1 X76.952 Y76.952 F7800.000
G1 E2.00000 F2400.00000
G1 X78.055 Y75.850 E2.04824 F1800.000
G1 X78.650 Y75.324 E2.07282
G1 X81.121 Y73.387 E2.16997
G1 X81.780 Y72.933 E2.19472
G1 X84.467 Y71.309 E2.29186
G1 X85.167 Y70.940 E2.31635
G1 X88.143 Y69.602 E2.41730

As an update, I can no longer reliably get the extruder motor to run (even when I pre-heat) from the LCD. Sometimes, it works fine, but other times it doesn't seem to. Will confirm whether switching the motor connector to the z-axis to test the motor works when I get home this evening.

I can confirm 1) that there is no tension pulling on the cable connections during the run, 2) the mainboard and motor connector aren't burned, cracked, and the mosfets have heatsinks on them, and 3) the extruder gear is fixed and rotates freely on the motor axis (I tested this by switching it over to the z-axis connection temporarily and confirming rotation).

Here's a photo of my motherboard:

A photo of my motherboard

Atticus29

Posted 2017-11-07T04:01:31.617

Reputation: 141

Check for proper T# assignment in the gcode. – Davo – 2017-11-07T11:51:07.633

What slicer app are you using to generate the gcode, and with what settings? – Carl Witthoft – 2017-11-07T13:50:01.903

Extruder won't work of the melting temperature has not been reached. verify if you have this prior to print M109 S195 (waits for 195°C) or M104 S210 (sets 210° temp during printing ) – Fernando Baltazar – 2017-11-07T17:30:23.317

I can confirm that the extruder was pre-heated to 220 C. I loaded an STL file into Repetier v. 1.0.2, used the built-in slicer (Slic3r) to generate my G-code. Question has been updated to reflect these details and display some sample G-code. – Atticus29 – 2017-11-08T18:52:20.967

To answer @ZuOverture's helpful question below, I was navigating in the LCD to move axis --> 1 mm --> extruder. Does that make sense? – Atticus29 – 2017-11-08T18:57:21.893

@Davo what do you mean by proper T# assignment? As in, "are there E's in the code?" ? – Atticus29 – 2017-11-08T20:24:35.917

Your symptoms are consistent with a line starting starting with T# where # is the extruder assignment; in this case, all "extrude" commands would be sent to a different head. See this RepRap G-Code wiki entry.

– Davo – 2017-11-09T12:27:34.597

@Davo. There was no T# in the entirety of the G code. Is that part of my problem, or does that mean that the issue is something else? – Atticus29 – 2017-11-12T01:42:09.243

Do the printer move during the print (but not extruding) or is it just sitting there waiting? – Valmond – 2017-11-13T08:33:06.623

@Valmond it's moving all around. – Atticus29 – 2017-11-13T22:39:50.870

Have you tried Valmond's suggestions, below? – Davo – 2017-12-14T12:17:05.083

Answers

1

According to all the information:

  • No reassignment of the extruder in the Gcode
  • You can extrude if you push the filament by hand
  • Extruder motor works when switched to Z driver
  • Z Motor works

I come to the conclusion that some of your electronics or the motor have fried.

What have fried? I tried to make a step by step check:

Switch drivers between E and Z, but plug the motors as usual:

1) Does the extruder extrude?

Yes: Your driver has fried

No:

2) Were you able to move the Z motor?

No: Motherboard And driver has fried

Yes:

3) Plug in the E motor on the Z driver, can you make the E motor turn?

Yes: Motherboard fried

No: Motor fried

HTH and keep us updated if it worked or not!

Valmond

Posted 2017-11-07T04:01:31.617

Reputation: 824

-1

This should have been a comment: when you say "manual extrusion", do you mean moving filament by hand or using extruder position commands from printer menu? Is extruder motor working at all? You can for example plug it instead of a Z-motor to check.

Suggested points to check:

  • Motor wire connections, both on extruder and mainboard. Are plugs experiencing tension (being tilted, pulled out) from improperly fixed cables?
  • Hardware on mainboard next to motor connector. Does it look burned, cracked, lacks heatsinks on mosfets?
  • Is extruder gear not fixed and rotating freely on extruder motor axis? You will hear sound of working motor, but it will look like it's not pulling the filament.

ZuOverture

Posted 2017-11-07T04:01:31.617

Reputation: 355

2

This does not provide an answer to the question. Once you have sufficient reputation you will be able to comment on any post; instead, provide answers that don't require clarification from the asker. - From Review

– tjb1 – 2017-11-07T12:09:31.017

Interesting. I'm feeling punished for trying to help someone. Is it supposed to help me help better? – ZuOverture – 2017-11-07T17:04:57.773

2Answers need to provide answers, this is not a forum. – tjb1 – 2017-11-07T20:21:55.773

@ZuOverture. I can confirm 1) that there is no tension pulling on the cable connections during the run, 2) the mainboard and motor connector aren't burned, cracked, and the mosfets have heatsinks on them, and 3) the extruder gear is fixed and rotates freely on the motor axis (I tested this by switching it over to the z-axis connection temporarily and confirming rotation). What would you recommend be the next step in troubleshooting? – Atticus29 – 2017-11-13T01:04:33.650

@Atticus29, your problem probably isn't with hardware, and that is good. You may try to double-check firmware and slicer settings related to extruding, remember which .gcode files were printing normally, try them again and compare to your last files. Tend to Davo's advice and check that your printer isn't set as model with 2 extruders in Repetier, try adding T1 (or is it T0?) explicitly to your code. Install Cura, use it to generate gcode, see if something changes. Also, if nothing else helps, you may try updating firmware on your mainboard. – ZuOverture – 2017-11-13T03:22:23.560

Wait, you cannot extrude with your print software? Check for fried drivers would be a start, fried controller board a second... – Valmond – 2017-11-13T08:35:12.680