<p>Printing with a brand new roll of Polymaker PolyLite grey PLA seems to have fixed the problem. I'll have to redo all of my tuning and do some more tests, but there's no sign of the under extrusion so far.</p>
<p>I ran out of the Inland turquoise PLA doing all my testing but I have tried drying the Inland black PLA+. I've dried it a total of 36 hours now at 50 °C and it made no improvement to the under extrusion issue. 24 hours of that was in a Sunlu S1 filament dryer (the original model without a fan) in 6 and 12 hour increments. 12 hours of that was in a convection toaster oven converted to a reflow oven with a <a href="https://whizoo.com/products/controleo3-reflow-oven-controller" rel="nofollow noreferrer">Controleo3 kit</a>. I tried drying with and without desiccant packs in both the filament dryer and the reflow oven.</p>
<p>I don't know how or why the filament degraded but it does not seem to be due to any current moisture content.</p>

CC BY-SA 4.0
2024-03-07T19:38:55.070Z
2024-03-11T19:37:13.943Z
2024-03-11T19:37:13.943Z
teovall
<p>I am getting this under extrusion on my prints but only after travel moves. The rest of the print looks fine.</p>
<p><a href="https://i.sstatic.net/GpCLg.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/GpCLg.jpg" alt="enter image description here" /></a>
<a href="https://i.sstatic.net/NugLo.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/NugLo.jpg" alt="enter image description here" /></a></p>
<p>My printer is a Monoprice Maker Select V2 (rebranded Wanhao Duplicator i3 V2) with a DiiiCooler with a radial fan. I was using Repetier 0.92.9 but have upgraded the firmware to Marlin bugfix-2.1.x commit 9e879a5b.</p>
<p>I'm using Cura 5.6.0 and the default Draft profile with the following settings changed:</p>
<ul>
<li>Wall Thickness: 1.2 mm</li>
<li>Print Thin Walls: True</li>
<li>Infill Density: 10%</li>
<li>Infill Pattern: gyroid</li>
<li>Print Speed: 50 mm/s</li>
<li>Travel Speed: 150 mm/s</li>
<li>Initial Layer Print Speed: 20 mm/s</li>
</ul>
<p>I'm printing with Inland Turquoise PLA at 215 °C and the build plate at 60 °C.</p>
<p>I am printing <a href="https://www.thingiverse.com/thing:4653297" rel="nofollow noreferrer">Kersey Fabrications Speed Test</a>.</p>
<p>I'm pulling my hair out. I've tried the following without making much headway:</p>
<ul>
<li>Completely disabled retraction - made the problem worse</li>
<li>Replaced the nozzle with a Micro Swiss Nickel Plated Brass 0.4 mm Nozzle for PTFE lined hotend and replaced the PTFE tube - no improvement</li>
<li>Lowered the temperature to 205 °C - no improvement</li>
<li>Changed firmware from Repetier 0.92.9 to Marlin bugfix-2.1.x commit 9e879a5b - no improvement</li>
<li>Enabled linear advance and tuned it using <a href="https://ellis3dp.com/Print-Tuning-Guide/articles/pressure_linear_advance/pattern_method.html" rel="nofollow noreferrer">these instructions</a>. The test pattern looked best at 0.25 but that only made a slight improvement to the issue</li>
<li>Set &quot;Max Comb Distance With No Retract&quot; to 10 mm - slight improvement</li>
<li>Tried different filament (Inland Black PLA+) - no improvement</li>
<li>Disabled &quot;Print Thin Walls&quot; - no improvement</li>
<li>Lowered part cooling fan speed to 25% - no improvement</li>
<li>Changed the following: - no improvement
<ul>
<li>Printing acceleration 600-&gt;1500</li>
<li>Retract acceleration 3000-&gt;2000</li>
<li>Travel acceleration 3000-&gt;2000</li>
<li>Junction deviation 0.2-&gt;0.1</li>
</ul>
</li>
<li>Lowered &quot;E maximum acceleration&quot; from 10000-&gt;100 - no improvement</li>
<li>Checked the extruder gear and it was clean. It has the newer D4 style extruder gear, not the duller slightly hobbed gear that Wanhao originally used.</li>
<li>I did the <a href="https://teachingtechyt.github.io/calibration.html#retraction" rel="nofollow noreferrer">Teaching Tech 3D Retraction Tuning</a> with a base feedrate of 60 mm/s.</li>
</ul>
<p>For the first print, I did 0.5-3 mm distance, 50 mm/s retract, 20 mm/s advance. There was very slight stringing at 0.5 mm and none in the other sections. All of the sections had slightly jagged edges except for 1 mm.</p>
<p>For the second print, I did 1 mm distance, 20-70 mm/s retract, 20 mm/s advance. There was no stringing and I didn't see any apparent difference between the sections.</p>
<p>For the third print, I did 1 mm distance, 50 mm/s retract, 10-50 mm/s advance. Again, no stringing and no differences between the sections.</p>
<p>None of the three prints showed any signs of under-extrusion.</p>
<ul>
<li><p>I printed the <a href="https://teachingtechyt.github.io/calibration.html#accel" rel="nofollow noreferrer">Teaching Tech 3D Acceleration Tuning Tower</a> and it has the same under extrusion issue in the back left corner inner wall. This would seem to rule out any slicer settings being the cause of this.</p>
<p><a href="https://i.sstatic.net/YxG6q.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/YxG6q.jpg" alt="enter image description here" /></a></p>
</li>
<li><p>I took apart the extruder and found that the v-groove idler wheel that pushes the filament against the extruder gear was full of grease.</p>
<p><a href="https://i.sstatic.net/KGjm7.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/KGjm7.jpg" alt="enter image description here" /></a></p>
</li>
</ul>
<p>It didn't spin freely, it turned but felt mushy. I cleaned the grease from the wheel and the surrounding area and added a drop of sewing machine oil to each side of the wheel. After that, it spun freely.</p>
<p>I did a cold check of my extruder steps with the extruder removed and found that it matched what I found earlier when I checked it hot through the hotend.</p>
<p>After reassembling the extruder, I reprinted the acceleration tuning tower from the same G-code as before but I saw no improvement to the under extrusion.</p>
<ul>
<li>I took apart the hot end and replaced the PTFE tube again. I was very careful to cut it perfectly straight and exactly the right length so that it was touching each end but not compressed. I also added Kingpin Cooling KPx thermal grease between the heat break tube and the cooling block and between the cooling block and the heatsink. After reassembling everything, I printed the acceleration tuning tower again but saw no improvement.</li>
<li>Printed the acceleration tuning tower at 30 mm/s, 0.5 mm retract, and 0.13 linear advance - no improvement</li>
<li>Printed the acceleration tuning tower at 225 °C, 195 °C, and 185 °C - no improvement</li>
<li>Checked extruder stepper current voltage reference on the Melzi board. I had adjusted the voltage for all four steppers years ago. The extruder stepper is rated for 1.02 A but the voltage reference was set to 0.695 V (0.87 A 85% of rated). It should be set to 90%. Either I set it wrong or it had drifted even though the other three were correct). I tried printing with it set to the factory setting of 0.886 V (1.1 A 109%) and the correct 0.734 V (0.92 A 90%) - no improvement either way</li>
<li>As suggested in the comments, printed the acceleration tuning tower with linear advance set to 0.04 and retraction distance set to 0.4 mm - no improvement.</li>
</ul>

CC BY-SA 4.0
2024-03-04T23:22:21.510Z
+1 for the *extensive* details. A very nice first question.
Greenonline
CC BY-SA 4.0
2024-03-05T15:34:26.940Z
You definitely seem to have ruled out many software-type issues.  Is it possible that these underextrusions are physically located close to each other on the bed?  If you have a worn or broken wire in your cable chain, it could be losing connectivity during some moves, causing repeated underextrusion in _parts_ of the print volume, if, for example, one of the extruder stepper signal wires is not consistently behaving.  It might be worth opening up the cable chains (if they open) and looking for damage.
Tal
CC BY-SA 4.0
2024-03-05T15:46:06.967Z
@Tal I had considered that but the under extrusion happens at different spots on the build plate. Looking at the previewer in Cura and other g-code analysis tools, the spots that are under extruded exactly match locations where the extruder starts extruding after a travel move.
teovall
CC BY-SA 4.0
2024-03-06T01:56:49.350Z
Can you try setting "Max Comb Distance With No Retract" to something like 1.5x to 2x the nozzle width? This essentially stops all unretracted travel except reversals at the end of solid "skin" fill.
R.. GitHub STOP HELPING ICE
CC BY-SA 4.0
2024-03-06T02:02:23.113Z
One detail that seems to be missing is your retraction length. Having retraction too long can cause problems resuming after retract, especially if your filament is at all wet. For a direct drive (I think this machine is DD; correct me if I'm wrong) more than 0.6 mm is probably way too much retraction, but that's assuming you have linear advance calibrated correctly, which you also didn't mention.
R.. GitHub STOP HELPING ICE
CC BY-SA 4.0
2024-03-06T04:03:41.880Z
@R..GitHubSTOPHELPINGICE I didn't try lower settings for "Max Comb Distance With No Retract" because the travel moves before the under extrusion were all further than 10mm. I'll try 0.8mm and see what happens though.

I know it was a long post so you probably missed it, but I did do retraction tuning and although there was no stringing at any distance, 1mm had the smoothest edge so I stuck with that.

I also tuned linear advance and found that 0.25 looked best but it only made a slight improvement to the under extrusion. Later on, also tried 0.13 with no further improvement.
teovall
CC BY-SA 4.0
2024-03-06T04:10:48.047Z
Actually, now that I think about it, "Max Comb Distance With No Retract" shouldn't matter since the problem happens with the Teaching Tech 3D Acceleration Tuning Tower generated from their website and it doesn't use combing.
teovall
CC BY-SA 4.0
2024-03-06T16:02:24.757Z
OK. 1 mm retraction and 0.13-0.25 linear advance are *extremely* high values for a direct drive extruder, closer to the range you'd expect for a short bowden like an original Ender 3. These could be seriously messing up your restarts. Reasonable ranges are probably 0.2-0.6 mm for retract and 0.03-0.06 s for linear advance K. If you tuned based on "make stringing go away" but had wet filament, or did your retraction tuning before lin-adv tuning (lin-adv must be done first since retraction tuning will otherwise pull in a compensation for missing lin-adv), this may have been the cause.
R.. GitHub STOP HELPING ICE
CC BY-SA 4.0
2024-03-06T19:23:51.577Z
I had the problem before I enabled linear advance. The version of Reptier I was originally on didn't have LA, that's part of the reason I switched to Marlin. I tuned LA before I tuned retraction, using the pattern method on Ellis' Tuning Guide. Lower values had significant bulging at the top, bottom, and corners of the pattern. 0.25 looked much better. When I tuned retraction, there wasn't any stringing at any distance from 0.5-3mm so I went by which distance had the smoothest edge which was 1mm. I'll give lower linear advance and retraction a try and let you know what I find.
teovall
CC BY-SA 4.0
2024-03-06T20:21:06.540Z
OK, here's another thought: is your hotend PTFE-lined? (For such an old model printer, the answer is very likely yes.) I recall this sort of symptom happening on PTFE-lined hotends when the tube isn't butted all the way against the nozzle, or when it's become damaged at the end contacting the nozzle from heat and wear. The gap there ends up acting as a sort of buffer that messes up restarts after retraction.
R.. GitHub STOP HELPING ICE
CC BY-SA 4.0
2024-03-06T20:32:56.237Z
@R..GitHubSTOPHELPINGICE I just tried printing the acceleration tuning tower with linear advance set to 0.04 and retraction distance at 0.4mm. No improvement. I've already replaced the PTFE tube twice. The second  time, I was very careful to cut it perfectly straight and the exact right length so it fit perfectly without being compressed.
teovall
CC BY-SA 4.0
2024-03-06T21:05:33.510Z
@teovall: "Perfectly without being compressed" might be too short. You need pressure that keeps molten plastic from squeezing into the gap. Back when I used a PTFE-lined hotend on my Ender, I would back the pneumatic coupler out one turn, push the tube all the way in to butt against the nozzle, then tighten the coupler to compress the tube end slightly against the nozzle.
R.. GitHub STOP HELPING ICE
CC BY-SA 4.0
2024-03-06T21:24:22.023Z
This under extrusion occurred with the original PTFE tube from the factory, the extra replacement tube included with the printer, and the tube that I cut myself. None of them made any difference to the issue. The last one I put in, that I cut myself, was snug without bending. I really don't think it's the issue.
teovall
<extruder><underextrusion><retraction><monoprice-maker-select><wanhao>
What is causing this under extrusion that only happens after travel moves
teovall
# What is causing this under extrusion that only happens after travel moves

(Asked by: username_0 on 2024-03-04)

I am getting this under extrusion on my prints but only after travel moves. The rest of the print looks fine.

[![enter image description here](https://i.sstatic.net/GpCLg.jpg)](https://i.sstatic.net/GpCLg.jpg)
[![enter image description here](https://i.sstatic.net/NugLo.jpg)](https://i.sstatic.net/NugLo.jpg)

My printer is a Monoprice Maker Select V2 (rebranded Wanhao Duplicator i3 V2) with a DiiiCooler with a radial fan. I was using Repetier 0.92.9 but have upgraded the firmware to Marlin bugfix-2.1.x commit 9e879a5b.

I'm using Cura 5.6.0 and the default Draft profile with the following settings changed:

* Wall Thickness: 1.2 mm
* Print Thin Walls: True
* Infill Density: 10%
* Infill Pattern: gyroid
* Print Speed: 50 mm/s
* Travel Speed: 150 mm/s
* Initial Layer Print Speed: 20 mm/s

I'm printing with Inland Turquoise PLA at 215 °C and the build plate at 60 °C.

I am printing [Kersey Fabrications Speed Test](https://www.thingiverse.com/thing:4653297).

I'm pulling my hair out. I've tried the following without making much headway:

* Completely disabled retraction - made the problem worse
* Replaced the nozzle with a Micro Swiss Nickel Plated Brass 0.4 mm Nozzle for PTFE lined hotend and replaced the PTFE tube - no improvement
* Lowered the temperature to 205 °C - no improvement
* Changed firmware from Repetier 0.92.9 to Marlin bugfix-2.1.x commit 9e879a5b - no improvement
* Enabled linear advance and tuned it using [these instructions](https://ellis3dp.com/Print-Tuning-Guide/articles/pressure_linear_advance/pattern_method.html). The test pattern looked best at 0.25 but that only made a slight improvement to the issue
* Set "Max Comb Distance With No Retract" to 10 mm - slight improvement
* Tried different filament (Inland Black PLA+) - no improvement
* Disabled "Print Thin Walls" - no improvement
* Lowered part cooling fan speed to 25% - no improvement
* Changed the following: - no improvement
  + Printing acceleration 600->1500
  + Retract acceleration 3000->2000
  + Travel acceleration 3000->2000
  + Junction deviation 0.2->0.1
* Lowered "E maximum acceleration" from 10000->100 - no improvement
* Checked the extruder gear and it was clean. It has the newer D4 style extruder gear, not the duller slightly hobbed gear that Wanhao originally used.
* I did the [Teaching Tech 3D Retraction Tuning](https://teachingtechyt.github.io/calibration.html#retraction) with a base feedrate of 60 mm/s.

For the first print, I did 0.5-3 mm distance, 50 mm/s retract, 20 mm/s advance. There was very slight stringing at 0.5 mm and none in the other sections. All of the sections had slightly jagged edges except for 1 mm.

For the second print, I did 1 mm distance, 20-70 mm/s retract, 20 mm/s advance. There was no stringing and I didn't see any apparent difference between the sections.

For the third print, I did 1 mm distance, 50 mm/s retract, 10-50 mm/s advance. Again, no stringing and no differences between the sections.

None of the three prints showed any signs of under-extrusion.

* I printed the [Teaching Tech 3D Acceleration Tuning Tower](https://teachingtechyt.github.io/calibration.html#accel) and it has the same under extrusion issue in the back left corner inner wall. This would seem to rule out any slicer settings being the cause of this.

  [![enter image description here](https://i.sstatic.net/YxG6q.jpg)](https://i.sstatic.net/YxG6q.jpg)
* I took apart the extruder and found that the v-groove idler wheel that pushes the filament against the extruder gear was full of grease.

  [![enter image description here](https://i.sstatic.net/KGjm7.jpg)](https://i.sstatic.net/KGjm7.jpg)

It didn't spin freely, it turned but felt mushy. I cleaned the grease from the wheel and the surrounding area and added a drop of sewing machine oil to each side of the wheel. After that, it spun freely.

I did a cold check of my extruder steps with the extruder removed and found that it matched what I found earlier when I checked it hot through the hotend.

After reassembling the extruder, I reprinted the acceleration tuning tower from the same G-code as before but I saw no improvement to the under extrusion.

* I took apart the hot end and replaced the PTFE tube again. I was very careful to cut it perfectly straight and exactly the right length so that it was touching each end but not compressed. I also added Kingpin Cooling KPx thermal grease between the heat break tube and the cooling block and between the cooling block and the heatsink. After reassembling everything, I printed the acceleration tuning tower again but saw no improvement.
* Printed the acceleration tuning tower at 30 mm/s, 0.5 mm retract, and 0.13 linear advance - no improvement
* Printed the acceleration tuning tower at 225 °C, 195 °C, and 185 °C - no improvement
* Checked extruder stepper current voltage reference on the Melzi board. I had adjusted the voltage for all four steppers years ago. The extruder stepper is rated for 1.02 A but the voltage reference was set to 0.695 V (0.87 A 85% of rated). It should be set to 90%. Either I set it wrong or it had drifted even though the other three were correct). I tried printing with it set to the factory setting of 0.886 V (1.1 A 109%) and the correct 0.734 V (0.92 A 90%) - no improvement either way
* As suggested in the comments, printed the acceleration tuning tower with linear advance set to 0.04 and retraction distance set to 0.4 mm - no improvement.

**Tags:** extruder, underextrusion, retraction, monoprice-maker-select, wanhao
> **Comments:**
> **username_1**: +1 for the *extensive* details. A very nice first question.  
> **username_2**: You definitely seem to have ruled out many software-type issues.  Is it possible that these underextrusions are physically located close to each other on the bed?  If you have a worn or broken wire in your cable chain, it could be losing connectivity during some moves, causing repeated underextrusion in _parts_ of the print volume, if, for example, one of the extruder stepper signal wires is not consistently behaving.  It might be worth opening up the cable chains (if they open) and looking for damage.  
> **username_0**: @Tal I had considered that but the under extrusion happens at different spots on the build plate. Looking at the previewer in Cura and other g-code analysis tools, the spots that are under extruded exactly match locations where the extruder starts extruding after a travel move.  
> **username_3**: Can you try setting "Max Comb Distance With No Retract" to something like 1.5x to 2x the nozzle width? This essentially stops all unretracted travel except reversals at the end of solid "skin" fill.  
> **username_3**: One detail that seems to be missing is your retraction length. Having retraction too long can cause problems resuming after retract, especially if your filament is at all wet. For a direct drive (I think this machine is DD; correct me if I'm wrong) more than 0.6 mm is probably way too much retraction, but that's assuming you have linear advance calibrated correctly, which you also didn't mention.  
> **username_0**: @R..GitHubSTOPHELPINGICE I didn't try lower settings for "Max Comb Distance With No Retract" because the travel moves before the under extrusion were all further than 10mm. I'll try 0.8mm and see what happens though.  I know it was a long post so you probably missed it, but I did do retraction tuning and although there was no stringing at any distance, 1mm had the smoothest edge so I stuck with that.  I also tuned linear advance and found that 0.25 looked best but it only made a slight improvement to the under extrusion. Later on, also tried 0.13 with no further improvement.  
> **username_0**: Actually, now that I think about it, "Max Comb Distance With No Retract" shouldn't matter since the problem happens with the Teaching Tech 3D Acceleration Tuning Tower generated from their website and it doesn't use combing.  
> **username_3**: OK. 1 mm retraction and 0.13-0.25 linear advance are *extremely* high values for a direct drive extruder, closer to the range you'd expect for a short bowden like an original Ender 3. These could be seriously messing up your restarts. Reasonable ranges are probably 0.2-0.6 mm for retract and 0.03-0.06 s for linear advance K. If you tuned based on "make stringing go away" but had wet filament, or did your retraction tuning before lin-adv tuning (lin-adv must be done first since retraction tuning will otherwise pull in a compensation for missing lin-adv), this may have been the cause.  
> **username_0**: I had the problem before I enabled linear advance. The version of Reptier I was originally on didn't have LA, that's part of the reason I switched to Marlin. I tuned LA before I tuned retraction, using the pattern method on Ellis' Tuning Guide. Lower values had significant bulging at the top, bottom, and corners of the pattern. 0.25 looked much better. When I tuned retraction, there wasn't any stringing at any distance from 0.5-3mm so I went by which distance had the smoothest edge which was 1mm. I'll give lower linear advance and retraction a try and let you know what I find.  
> **username_3**: OK, here's another thought: is your hotend PTFE-lined? (For such an old model printer, the answer is very likely yes.) I recall this sort of symptom happening on PTFE-lined hotends when the tube isn't butted all the way against the nozzle, or when it's become damaged at the end contacting the nozzle from heat and wear. The gap there ends up acting as a sort of buffer that messes up restarts after retraction.  
> **username_0**: @R..GitHubSTOPHELPINGICE I just tried printing the acceleration tuning tower with linear advance set to 0.04 and retraction distance at 0.4mm. No improvement. I've already replaced the PTFE tube twice. The second  time, I was very careful to cut it perfectly straight and the exact right length so it fit perfectly without being compressed.  
> **username_3**: @teovall: "Perfectly without being compressed" might be too short. You need pressure that keeps molten plastic from squeezing into the gap. Back when I used a PTFE-lined hotend on my Ender, I would back the pneumatic coupler out one turn, push the tube all the way in to butt against the nozzle, then tighten the coupler to compress the tube end slightly against the nozzle.  
> **username_0**: This under extrusion occurred with the original PTFE tube from the factory, the extra replacement tube included with the printer, and the tube that I cut myself. None of them made any difference to the issue. The last one I put in, that I cut myself, was snug without bending. I really don't think it's the issue.  

---

## 1 answers

### Answer by username_0 on 2024-03-07. Score: 2 | Accepted answer

Printing with a brand new roll of Polymaker PolyLite grey PLA seems to have fixed the problem. I'll have to redo all of my tuning and do some more tests, but there's no sign of the under extrusion so far.

I ran out of the Inland turquoise PLA doing all my testing but I have tried drying the Inland black PLA+. I've dried it a total of 36 hours now at 50 °C and it made no improvement to the under extrusion issue. 24 hours of that was in a Sunlu S1 filament dryer (the original model without a fan) in 6 and 12 hour increments. 12 hours of that was in a convection toaster oven converted to a reflow oven with a [Controleo3 kit](https://whizoo.com/products/controleo3-reflow-oven-controller). I tried drying with and without desiccant packs in both the filament dryer and the reflow oven.

I don't know how or why the filament degraded but it does not seem to be due to any current moisture content.


---

