Help with Inconsistent Layer Lines on Ultimaker S5 – Particularly Left Side of Prints

[TEFletcherr 0]

Hi everyone,

I've been running into issues with my Ultimaker S5 lately and am hoping someone might have some advice. The main problem I’m facing is inconsistent quality in the layer lines, especially noticeable on the left-hand side of any vertical walls in the prints. This has been causing some frustration, as I can’t seem to pinpoint the cause.

 

Here’s a bit more detail about my setup and troubleshooting so far:

• Settings: I’m primarily using base Cura settings with slight temperature adjustments to accommodate the filament I'm working with. I typically use reflow Earth Collection rPLA, but I’ve also tried PolyTerra and a few other brands, all with the same results. This makes me think it’s not a filament-specific issue.

• Maintenance: I’ve recently gone through the standard maintenance routines. The feeders have been cleaned and regreased, the axles are greased, and the belt tension seems okay. I’ve also tightened the screws on the axles and ran the calibration test. Everything appears to be running smoothly, so I’m not sure if it’s hardware-related.

 

Unfortunately, I'm unable to share the 3D files, so I know that limits what can be checked there but I don't think their an issue anyway.

 

Has anyone encountered similar issues or have any suggestions on what else I could check or adjust? I'd appreciate any insights, especially if there are Cura tweaks or hardware adjustments that might help address this problem.

 

Thanks in advance for any help!

 

Edited November 1 by TEFletcherr

[gr5 2,265]

If the Z axis moves slightly too far then that layer will be underextruded because the gap to be filled is bigger than expected and not enough filament is coming out of the nozzle.  So the layer will stick inwards a bit.

 

If the Z axis moves slightly less than desired then similarly, the layer will be slightly overextruded and will stick out a bit.

 

Usually the Z axis is calibrated perfectly long term but each individual layer sees small errors that are recoverred on either the next layer or certainly within a few layers but you get this horizontal banding that I see on your print.

 

1) The easiest fix is to do thicker layer lines.  If you double the thickness of the layers then the error will be a smaller percentage of the total movement of a layer so you get correspondingly smaller amounts of over/under extrusion.

 

2) Another fix is to clean your Z screw very very well.  Your parts actually look quite good so to improve them you really have to remove the Z axis (I think it's pretty easy - just 4 screws under the printer but you have to also unplug the Z servo so more screws to remove the bottom cover - careful, if you have an S5R1 (versus S5R2) there are deadly voltages so unplug the printer if you remove the bottom cover.  Once the 4 screws are removed the stepper motor and Z screw slide out the bottom of the printer.  Put it over newspaper.

 

Whether you take it out or not, clean with WD40 and a toothbrush - remember it's a triple helix so make sure the toothbrush gets into all 3 independent threads.  Remove all grease and oils, then dry, then regrease with one pea sized drop of grease and no more.  Concentrate on the thread farthest from the motor since you are printing "small" parts.

 

3) Placing a heavy weight such as a brick or lead weight at the back of the bed near where the screw passes through sometimes also helps get the layer heights consistent but do this after the leveling process is complete!

[TEFletcherr 0]

@gr5 

Thank you so much for the detailed response! The explanations for under/over extrusion based on the Z-axis movement make a lot of sense, especially when I think about how it could contribute to the horizontal banding I'm seeing. I really appreciate the breakdown of potential solutions.

 

It’s interesting because the inconsistent layer lines really do seem concentrated on the left side of each wall. Could an uneven or slightly misaligned Z-axis also create more issues on one side than the other?

 

Cleaning the Z-screw was one of the last things on my list to tackle since it seemed like a big project. But your instructions definitely make the process feel a bit more approachable!

 

Thanks again for all the advice!

[gr5 2,265]

The left side issue is probably unrelated.  I mean it's possible the bed moves most of the way initially and then very slowly slides farther down over the next 5 seconds but I seriously doubt it.

 

The side issue is probably related to your model shape or that's maybe where your z-seam is and it's just exacerbating the issue.  Make sure "retract on layer change" is disabled as that can make the initial printing on a new layer underextrude.  Also maybe look at PREPARE mode and play through a known "bad layer" and watch the first few seconds of how it starts printing the outermost layer - what happens just before (does it print infill just before?  inner wall just before?).  Make sure there are no retractions or long distance moves or speed changes when it starts the outermost wall.

[TEFletcherr 0]

@gr5

Here’s the latest print (Green & Orange) compared to a previous one (Red & White). It shows that the location of the layer inconsistency shifts each time. Some prints, like the red and white one, have perfect connections between the two filaments/extruders, which makes me think the problem lies with the printer rather than the model or slicer. I’ve thoroughly scanned the model in the slicer and haven’t observed any issues there.

 

The inconsistency seems to fade as it goes around the model, and it doesn’t appear in exactly the same spot every time. However, other issues are also present, like small holes in the orange section. This filament is brand new, so I’m not sure if it’s a moisture issue or if there might be a slight block in the extruder. There are also minor holes on the last corner where the inconsistency occurs, along with some shrinkage in the first layers due to the thicker base.

Edited November 5 by TEFletcherr

[gr5 2,265]

These conversations go on for days and I apologize for my laziness in not rereading everything but note that PLA does not need to be dried or kept dry. PLA can be left in the open, humid air for years.  CPE or PETG left in open air goes bad within a few days, certainly within a week.  It still prints okay but you get tons of stringing.  PVA/Nylon changes it's printing quality in just 20 minutes.  The quality of a print is often different from the begining to the end.  Leaving PVA or Nylon in open air for a day means you absolutely have to dry it. Wet Nylon prints really horribly and prints usually fail. But I have noticed no issues with PLA.  I could be wrong but the issues are minor compared to other filaments.

 

Your prints are much better than mine.  These look absolutely fantastic.  You must be doing some kind of artistic piece for caring a lot about the quality?  Personally I mostly do functional parts that can look like crap as long as they work.  So we have different focus.  To improve quality more, print even slower.  Maybe 15mm/sec?  I don't know.

 

Now we come to the important stuff:

 

1) If the problem is with the Z axis, you will see an exactly equal amount (on average) of layers that are overextruded (sticking out) as underextruded (sticking in) and this is over a small vertical space - say 1mm.  And after you print 2 consequtive parts that are very different in shape (say a pikachu and then a cube), you will tend to see the worst horizontal lines at the exact same height (not every line will match up but enough to be quite striking).

 

However if the problem is only underextruded (sticking in or even air holes) and there are no overextruded layers (typically the very next layer upwards) then your issue is not with the Z axis.

 

2) I don't think you tried my simplest trick of all - make the layer height thicker.  For beautiful parts, thick layer lines helps in my opinion.  It will hide so many defects!  On the other hand it will have thick layer lines.  Which I actually like the look of but it's subjective: "in the eye of the beholder" and many people don't like layer lines.  I don't know why.  I think they are great.  Do these people hate corduroy also?  Probably.

 

3) So you arrow/circle a few issues.  I don't think they are all the same issue but in general they do not look like Z height issues anymore.  These all look like random undrextrusion.  I don't know what is causing those.  Several of them may be at layer change and really you should look at the print in PREPARE mode and see if those spots have something different than other layers.  I suspect most of your issues are near the layer change but really you should check.  You will definitely learn something (not necessarily what the problem is but maybe).  Know that you can alter the order of printing - for example print outer surface first.  Or print it last.  In general, underextrusion issues can typically be fixed by printing slower as the pressure in the nozzle is less extreme and the feeder has an easier time of it.  It could be something like a filament tangle or 25 other things causing intermittent underextrusion.

 

 

[gr5 2,265]

Oh - and if you slow down the printing speed, it's important to do it for all the printing speeds (there's about 7 of them) and make them all the same and the travel speeds need to stay fast.  150mm/sec minimum.