Underextrusion on outer wall

[sophocha 2]

Hi all,

I always had underextrusion problems on my ender 3 since day one (specifically on long runs).Tried to fix it by slowing the speed down and it did work for the majority of my prints.I have recently switched to cura 4.2.1 and it seems that the problem is more severe now on cylindrical models.Look at the pic.Same profile, cura 3.6 on the right, cura 4.2.1 on the left. When the nozzle switch from infill to outer wall (even with retraction off!!) it still underextrudes! Tried some prime setttings but it seems nothing works. The rest of the print is spot on except the dreadful start of each outer layer.

[Smithy 1,135]

I have heard that the Ender 3 has some problems with the feeder gear tension. There are some mods to make it stronger and more reliable. If the filament slips through the gear on your feeder, that could be a reason for under extrusion.

 

Check out the Ender forums or search on Thingiverse for modifications.

[sophocha 2]

2 minutes ago, Smithy said:

I have heard that the Ender 3 has some problems with the feeder gear tension. There are some mods to make it stronger and more reliable. If the filament slips through the gear on your feeder, that could be a reason for under extrusion.

 

Check out the Ender forums or search on Thingiverse for modifications.

I have changed the feeder gear into a metallic one.No more grinding the filament.I think the problem lies elsewhere. Everything is perfect except the very beginning of a layer.Maybe I will change the speed to a very low setting so that I can pinpoint where the problem is and go from there.

[sophocha 2]

well well, look at that....perfect outer layer.

 

1) Stick with Cura 4.2.1. Much better improved profiles.

2) No more old customized profiles.I just ditched everything....Choose the draft profile from the settings.

3) In my case, raise the temp up a little bit (210).

4) Z seam alignment (shortest) with "hide seam"

5) See the photo. Almost perfect outer wall. I knew it wasn't my printers' fault.I can go really fast as well. Do not know what the problem was. Maybe I over-tweaked some settings... 

Edited August 6, 2019 by sophocha

[Smithy 1,135]

1 hour ago, sophocha said:

Maybe I over-tweaked some settings... 

 

Yes, that can happen faster than you think.

But good to hear that it is working now for you.

[walpolea 0]

Having this exact issue as well in 4.2.1 with minimally tweaked default profiles for CR-10. Any insights into which setting might be the culprit? I've played around with a few that I thought might have had an effect, but no dice.

[qwewer 0]

Do you still have the old profile? I really want to compare it to the default, because I too have/had that problem.

[sophocha 2]

Here is my new Cura profile on 4.3 (0.6 nozzle and PETG)

 

I think something is terribly wrong with the outer wall settings of Cura. I was always ending up with uneven walls, over-extrusion on the edges, under extrusion at the beginning of a layer, LOTS of stringing on PETG, etc. 

 

Here is a  Calibration Cube  print.

 

The one on the left is my perfect print after I tweaked my settings. Things I have done: 

 

1) Decrease my flow to 96% (Except the initial flow 98%).That helped a lot on the definition of the prints.Much cleaner prints now.  

2) Make the out wall count to at least 3. That eliminated infill showing on the outer walls.

3) THE MOST IMPORTANT SETTING.....Z seam alignment  to SHORTEST and seam corner to "hide seam". This is crucial. Any other combination of settings produced uneven outer walls, blobs and lines on the outer walls (see the obvious line in the middle of the calibration cube...middle cube in the photo).The start of each of the outer layers is slightly off with any other settings, so this produced a smooth,even outer layer. 

4) Printing temperature @ 210 no matter what everybody is saying!!  (printing at 230-240)  produces a lot of stringing on PETG. Printing at 210 made all of my prints perfect! I also have a Petsfang mod with a big fan, but I have all my fan speeds at 50%. Also, "filter out tiny gaps" (enabled). If you don't have this ON it also produces a lot of stringing cause it tries to fill the gaps and the extra filament sticks to the nozzle. 

5) Obviously enable retraction( in my case 6mm, 50mm/s speed). 

6) Printing speed around 30 to 40mm/s except the 1st layer.Also, buy a creality glass bed and some hair spray. No more problems with elephant foot or not sticking to the surface. This solved all of my issues with big prints coming off the plate. Now I have to wait for them to cool down in order to take them off the bed!

7) Enable jerk control and change the outer wall jerk to 5 mm/s.That also solved the over-extrusion/bulgy edges. Much more smooth edges!

😎 Enable coasting. I wasn't having any luck in the past with this, BUT with all these settings in mind, enabling this (default settings) will help alleviating any seam showing too much on the outer wall.....and last....

9) Outer wall wipe distance....make this 0.4mm to 0.6mm. This creates great starting layers because it wipes the nozzle. 

 

There! You now have the perfect profile for PETG.   

2020 PETG 0.6 coasting less flow.curaprofile

Edited January 4, 2020 by sophocha

[sophocha 2]

More testing on this profile. It looks really good for a PETG print on a 0.6 nozzle.

 

Edited January 3, 2020 by sophocha

[sophocha 2]

....also, if you want to avoid stringing on PETG, do this mod. Take a dab of silicone, and cover your nozzle with it. Raise your temps @ 100 to cure it. Take it off and cut the very tip with a razor, just barely seeing your nozzle tip. Voila. Now the extra filament won't stick to your nozzle and make a stringing mess.

 

Edited January 4, 2020 by sophocha

[carlfrec 0]

hey ! when I try to download the Cura profile, I get a file named differently and is not recognized in Cura. Here is a picture of the file once downloaded on my computer. Any idea ?

Edited January 2, 2021 by carlfrec

[wortex 0]

Hi ihave same problem cura 4.9.1 underextrusion on outher wall pla filament. Temp.190° and all cura setting is defoult 0.2 mm draft. Printer is steel i3 and there is no any problem except round surfaces. Has anyone encountered and solved this problem?

[gr5 2,004]

It looks like the underextrusion is happening on layer change and you have very thin walls.  So:

 

Make sure retract at layer change is unchecked.

Make sure enable coasting is unchecked

 

Do you have "spiralize outer contour" checked?  If so uncheck that as well.

[gr5 2,004]

You might also want to tune your printer to make layer change happen as fast as possible.  Crank up the acceleration and max speed on the Z.  I got it so fast the layer change is now kind of a "click" sound.  This has nothing to do with cura but the longer the Z change takes, the more you get out of equilibrium pressure and issues of over and under extrusion.

 

Do you have linear advance turned on for your printer?  That could also cause this issue if you have the wrong value for linear advance.

[wortex 0]

yes underextrusion is happening on layer change i try before your advise( retract at layer change,enable coasting,haven't linear advance.spiralize outher counter) but not solved.i thing there is no any problem with the  printer. Now i use purusa silecer no any problem.in the cura software this happens when the circular diameter gets bigger. The other parts written properly.nozzle 0.4 mm wall thicnes 0.8 mm

[gr5 2,004]

 

Please share your project file: go to menu "file" "save...".  The resulting file contains not only your STL but the scaling, positioning.  Also it has your machine (printer) settings, your material settings, your profile used, and settings that you overrode.  Please post that here.

[wortex 0]

ok added thanks.

CFFFP_Fan_Casing.3mf CFFFP_Mixer.3mf

[gr5 2,004]

Ah!  I see the problem.

 

 

 

 

[gr5 2,004]

So in the image above that I posted you can see that on one of those layers where the wall is thinner, it starts printing the new layer right  where you have underextrusion.

 

More importantly that's also where it starts the outer shell (after it finishes the inner shell).

 

So the inner shell lines are extremely thin - it is barely extruding at all - it's trying to fill in the gap between the outer shell but your walls of your model are not much more than 0.8mm thick here.  If the wall is 1mm thick then it's extruding 0.4mm thick lines on the outer shell but that leaves only 0.2mm (0.1mm on each pass) for the inner wall.

 

Then it suddenly jumps from extruding almost nothing to full on 0.4mm thick beads and it takes a while to equalize so it underextrudes.

 

Solutions:

 

1) Make the part closer to an integral of 0.8mm thick so make the part 0.8mm or 1.6mm thick instead of about 1mm thick on this thin walls where it's underextruding.  If you aim for 0.8mm you might also have to check the box "print thin walls"

 

2) Check the box "outer before inner walls".  This will make the switchover problem occur on the support which doesn't care so much.

 

In addition I'd consider making all printing speeds the same at 30mm/sec.  Speed changes can cause under or overextrusion.  But that's not the problem in this example.

[rh224 1]

I am having a similar issue with my Ender 3 Pro and Cura 4.9.1.  My wall thickness is 1.2mm so each wall is made of 3 lines. I've been trying different settings and nothing seems to fix the problem.  What seems to be happening is the inner (center) wall prints, followed by the inside outer wall. Then, instead of traveling directly to the start of the outside outer wall, the entire center inner wall is traversed again, except with no extrusion, before moving to the outside outer wall. I've watched my extruder and there is no positive or negative movement during this movement. I'm pretty sure traversing the inner wall again is leaving the nozzle voided due to oozing and then leads to the under extrusion. 

 

I can't find any setting that changes this behavior. To either eliminate the 2nd "dry" traversal of the inner wall, or to trigger a retraction so the nozzle is re-primed at the start of the outside outer wall. I've tried turning combing off and Fill Gaps between Walls and others. 

 

Any help or insight would be appreciated.

 

 

 

3linewalls.3mf

[gr5 2,004]

I loaded your project and see what you mean.  I tried everything I could think of.  I even tried a different version of Cura.  If you set horizontal expansion to 0.1mm you can see that it's filling the wall gap.

 

Here's the basic problem I think:  Cura always has to do an even number of passes.  The red lines are the outer shell passes and then it does 2 inner shell passes.

 

So you could set your nozzle width to 0.3mm  (0.3 * 4 = 1.2mm perfectly) then it does it nicely.  And it will print reasonably well but the quality might be slightly worse (not better) than what you are doing now.

 

Or better - you can make the inner passes more equal - set the "wall thickness" to 0.6 (half of your 1.2) and make the outer wall 0.4 and inner wall 0.2mm.  0.4+0.2+0.2+0.4 = 1.2mm.

 

You could also try the beta version of cura 5.0, code named Arachne.  It will (I believe) do an odd number of passes on walls which is what you need.  I have not tried Arachne.

 

[rh224 1]

Good to know it isn't just me. 🙂 

 

I have stumbled onto a bit of a workaround by turning on Outer Before Inner Walls and then turning on Retract at Layer Change and adding a little Extra Prime Amount. It doesn't eliminate the 2nd pass, but since the outside wall prints right at the start of the layer, the nozzle is fully primed. It works for the type of print I'm doing, which is pretty much all straight unsupported wall.  I don't think it would work as well for something more intricate.

 

I will look into trying the beta and your other suggestions. Thanks for your help!

[emiemi 0]

I've had the same issue. Using an Ender3 Pro trying to print a box with rounded corners modeled by me on openscad.

My model looks is very similar to @rh224's model. After reading this thread I downloaded the Cura 5 beta and  printed the same model with the same settings.... and voila! the issue is gone. 

 

Thank you so much guys!

[iceman2511 0]

what worked for me was enabling outer wall wipe distance to around 3mm, that's all that i enabled and it instantly fixed it, no prime amount or anything!, just outer wall wipe distance