<p>A close inspection of what happened when printing the first layer resulted in this:</p>

<ul>
<li>The missing steps on the new print came from the nozzle scraping too close to the print surface, which lead to no first layer</li>
<li>Readjusting the Z-axis end stop, which had moved down, resulted in no more lost steps, but the print not sticking for the first test.</li>
<li><p>Releveling the bed and making sure the bar was parallel to the bed resulted in a perfect first layer.</p></li>
<li><p>Lost steps and under-extrusion could not be replicated after 48 hours of <em>rest</em> for the printer.</p></li>
</ul>

<p>I have no idea why the print had failed due to under-extrusion <em>during</em> the print, but apparently, my immediate tests were flawed enough to not detect the first layer height resulting in getting almost no extrusion. This I mistook for massive under-extrusion, making me believe something else was at fault.</p>

CC BY-SA 4.0
2018-09-04T10:09:23.527Z
2018-09-06T21:46:46.733Z
2018-09-06T21:46:46.733Z
Trish
<p>Sounds similar to something I experienced with my Y-axis. The grub screw on the toothed wheel had come a little loose, and I was experiencing a reasonably consistent degree of slip.</p>

<p>In the extruder particularly, these locking screws might not be too obvious to check.</p>

CC BY-SA 4.0
2018-09-02T10:09:27.110Z
sadly this can't be the error: after inspection, the gear is very tightly mounted to the motor and can't turn freely, the 2 grubs make it impossible for the gear to slig; one is pressing onto the flat of the motor shaft
Trish
CC BY-SA 4.0
2018-09-02T09:27:23.017Z
2018-09-02T09:27:23.017Z
Sean Houlihane
<p>I have printed a couple weeks perfectly fine with my Ender 3. Two weeks ago I changed the firmware but the settings were all fine and resulted in good prints.</p>

<p>Now, suddenly <em>during</em> a print the extruder motor started to under-extrude.</p>

<p>I thought "hey, could be the file" and used a test file that printed well two weeks ago: Under-extrusion, barely a line.</p>

<p>I looked at the extruder, no filament grinding, no clicking from lost steps or moving against pressure. The Bowden tube is firmly seated though.</p>

<p>I measured what is coming out: instead of 50&nbsp;mm I ordered to push into the hotend got 28.7&nbsp;mm. So I went and looked at the steps/mm, which is 93, exactly what it is also on the TronXY X1, which uses pretty much the same extruder setup but for a different style, same sized gear.</p>

<p>I cleaned out the nozzle nevertheless, but that didn't change the results.</p>

<p>What might be wrong and how can I fix it?!</p>

<p>Edit:</p>

<ul>
<li>Touching the filament while I was printing a freshly sliced test, I realized it DID lose steps, just the filament did slip back (almost) quietly. Pressing a finger on the filament made me able to feel the shiver in it.</li>
<li>Inspecting what was printed showed, that the nozzle had migrated against the print platform a little over the weeks.</li>
</ul>

CC BY-SA 4.0
2018-09-02T14:43:17.803Z
Can you change the stepper driver, or is this on a slotted on stepper driver print board?
0scar
CC BY-SA 4.0
2018-09-02T14:45:12.563Z
The Board can't Change them.
Trish
CC BY-SA 4.0
2018-09-02T21:18:57.610Z
Sounds like missing steps, could be the stepper driver is not functioning correctly, or, the stepper is somehow missing steps. Have you tried swapping the stepper motors?
0scar
<extruder><print-quality><creality-ender-3>
Sudden underextrusion on Ender3
Trish
# Sudden underextrusion on Ender3

(Asked by: username_0 on 2018-09-02)

I have printed a couple weeks perfectly fine with my Ender 3. Two weeks ago I changed the firmware but the settings were all fine and resulted in good prints.

Now, suddenly *during* a print the extruder motor started to under-extrude.

I thought "hey, could be the file" and used a test file that printed well two weeks ago: Under-extrusion, barely a line.

I looked at the extruder, no filament grinding, no clicking from lost steps or moving against pressure. The Bowden tube is firmly seated though.

I measured what is coming out: instead of 50 mm I ordered to push into the hotend got 28.7 mm. So I went and looked at the steps/mm, which is 93, exactly what it is also on the TronXY X1, which uses pretty much the same extruder setup but for a different style, same sized gear.

I cleaned out the nozzle nevertheless, but that didn't change the results.

What might be wrong and how can I fix it?!

Edit:

* Touching the filament while I was printing a freshly sliced test, I realized it DID lose steps, just the filament did slip back (almost) quietly. Pressing a finger on the filament made me able to feel the shiver in it.
* Inspecting what was printed showed, that the nozzle had migrated against the print platform a little over the weeks.

**Tags:** extruder, print-quality, creality-ender-3

> **Comments:**
> **username_1**: Can you change the stepper driver, or is this on a slotted on stepper driver print board?  
> **username_0**: The Board can't Change them.  
> **username_1**: Sounds like missing steps, could be the stepper driver is not functioning correctly, or, the stepper is somehow missing steps. Have you tried swapping the stepper motors?  

---

## 2 answers

### Answer by username_0 on 2018-09-04. Score: 3 | Accepted answer

A close inspection of what happened when printing the first layer resulted in this:

* The missing steps on the new print came from the nozzle scraping too close to the print surface, which lead to no first layer
* Readjusting the Z-axis end stop, which had moved down, resulted in no more lost steps, but the print not sticking for the first test.
* Releveling the bed and making sure the bar was parallel to the bed resulted in a perfect first layer.
* Lost steps and under-extrusion could not be replicated after 48 hours of *rest* for the printer.

I have no idea why the print had failed due to under-extrusion *during* the print, but apparently, my immediate tests were flawed enough to not detect the first layer height resulting in getting almost no extrusion. This I mistook for massive under-extrusion, making me believe something else was at fault.


---

### Answer by username_2 on 2018-09-02. Score: 0

Sounds similar to something I experienced with my Y-axis. The grub screw on the toothed wheel had come a little loose, and I was experiencing a reasonably consistent degree of slip.

In the extruder particularly, these locking screws might not be too obvious to check.

> **Comments:**
> **username_0**: sadly this can't be the error: after inspection, the gear is very tightly mounted to the motor and can't turn freely, the 2 grubs make it impossible for the gear to slig; one is pressing onto the flat of the motor shaft  

---

