Vertical delamination  

We are just coming up to the time of year when humidity changes, switching air conditioning and central heating, and changes in ventilation patterns mean that a great many questions will attract the same answer:  Dry your filament.

Try it.  Come back if problems persist.

Cheerio,

RE:

Are the delaminations also on the other sides of the object? If you printed the object in the way shown, so x-axis about left-right and y-axis mainly forward-aft, you may also want to check the y-axis belt and its tension. The Y-axis system design, at least on my (November 2023) MK4, is not well designed.  I even read some reports the belt tensioner screw got dislodged. On Printables there's designs of more sturdy motor supports and idlers with a facility for tensioning.  

RE: Vertical delamination

@Diem: Yes, you are right. That's why I keep my filament in sealed plastic boxes with a lot of silica.

@efvee: The delamination actually occurs mainly in the Y-axis direction. I will check the belt and also rotate the object 90 degrees as a test.

Thanks for your replies. 👍 

RE: Vertical delamination

Is the first layer ok ?  A cold pull does not do any harm either 😉  (maybe some dirt in the nozzle ?)

Also,  a while ago, i had a little bit of PETG oozing out while the printer started with the pre-print leveling.  First layer was not good than, because Z-offset was "off".

I always watch out for oozing filament now 🙂

RE: Vertical delamination

The first layer is perfect (in most cases). 😉 

I cleaned the nozzle with a needle. When die Y-belt ist not the problem, I will try a cold-pull.

RE: Vertical delamination

Unfortunately the belts weren't the problem. Both were about 10 Hz too low. I corrected both, but the delamination problem hasn't changed.
But it actually always delaminates in the same place - on the back wall. Even if I rotate the object.

But I made a mistake. I thought the gcode files were from 3 weeks ago when printing was still working. But that wasn't true. These were all new print files that I created with the new PrusaSlicer 2.7.2. So it could also be a slicer problem. I'm going to try out an old gcode file this evening.

RE: Vertical delamination

Ok. I tried an old gcode file with the filament that worked 3 weeks ago. Didn't work.

I made 2 cold pulls as described here:
https://help.prusa3d.com/article/cold-pull-mk4-mk3-9-xl_445071
Both looked clean. But didn't work.

Has anyone any idea what I could try else before I change back to my slow Ender 3 that never had such a problem. 🙁 

RE: Vertical delamination

I searched the forum for similar problems. Could this be the same problem:
https://forum.prusa3d.com/forum/prusaslicer/delamination-of-perimeters-or-under-extrusion-with-arachne/#post-624052

It's an old issue from 2022 and I don't know what Arachne is and if it is active by default.

RE: Vertical delamination

That might be an issue with the Nextruder. Check everything. Screws can and will loosen over time due to vibration.

I recently experienced loose screws on my XL Nextruder docks that caused a lot of problems.

Design a model to test.

Example: tube Outside radius 20 mm, inside radius 17 mm, height 60 mm.

Try using PLA. Run the print and watch it carefully as the z axis increases.

RE: Vertical delamination

After understanding the problem with Arachne, I have now even found 3 solutions that solved the problem:

1. Switch off Arachne (-> Classic Mode)

2. Change the wall thickness from 2mm to 2.4mm. Then the walls are printed with infill and the effect does not occur.

3. Set the extrusion factor for the filament to 1.1.

So Prusa is obviously right that it is actually an under extrusion problem.
Now I would like to know why I suddenly have under extrusion after it worked perfectly for 3 weeks.

RE: Vertical delamination

Posted by: @kc

That might be an issue with the Nextruder. Check everything. Screws can and will loosen over time due to vibration.

I recently experienced loose screws on my XL Nextruder docks that caused a lot of problems.

I allready fastened all screws when I fixed the belt tension.

RE:

That's why I keep my filament in sealed plastic boxes with a lot of silica.

That may not be enough, try actively drying.

Last week was mild and wet, I didn't use my central heating and one 9 hour print started fine but was deteriorating by the end.

Cheerio,

RE:

Posted by: @diem

That's why I keep my filament in sealed plastic boxes with a lot of silica.

That may not be enough, try actively drying.

Last week was mild and wet, I didn't use my central heating and one 9 hour print started fine but was deteriorating by the end.

This is a myth from companies that sell expensive drying equipment. 😉 
If you store the filament in a very dry environment, the moisture will be removed. That's physics. It just takes longer.

And filament does not get wet in 9 hours. Otherwise professional print farms with open filament wouldn't work.

And filament does not get wet in 9 hours.

Sometimes it's less.  Try drying it.

Cheerio,

RE:

You are printing wool threads. 😋 

The test print for the delamination problem only took 3 hours and you can see the first delamnination effect after just 1 hour.

And as I said, I use only tried filament.

RE: Vertical delamination - problem solved!

A replacement nozzle arrived today (and an adapter) and I installed the nozzle straight away and printed the old gcode file from 3 weeks ago again.

Everything fine! No delamination with Arachne and 2mm wall thickness.

The whole problem arose from a worn or partially clogged nozzle, which I would have replaced as a test days ago if I had had a replacement.