Weird wall surface holes. Any ideas?

[PeterPan 0]

Hi,

can anybody help me with my weird surface artifacts.

I have been getting these weird holes in the walls of my prints recently.

Sometimes they manifest as tiny holes and sometimes they are barely visible but still there.

They tend to stay mostly in the same wall and don’t distribute like the random seam blobs.

 

I print on a heavily modified Ender 3. I also use the Eibos filament dryer and the slice engineering bimetal heat brake.

 

I have changed EVERY setting in cura and prusa slicer back and forth but I can’t find any good correlation.

 

I was able to reduce the artifacts by turning off the retraction setting but then I obviously get crazy stringing. I also don’t understand why retraction would be relevant in the middle of a wall that is not crossed.

I need about 3 – 4 mm of retraction to control stringing.

 

I have tried filament from geeetech, eryone and prusament but that doesn’t make a difference either.

 

I can not find any information on this type of artifact anywhere. Has anybody ever seen these types of artifacts? Any help would be very much appreciated.

 

 

 

Edited October 16, 2022 by PeterPan
better pictures

[GregValiant 1,141]

Did you notice if the print head was stuttering?  If it is stopping for just a fraction of a second you can get divots like that as the nozzle re-softens the plastic near it.

[PeterPan 0]

No, I didn't notice any stuttering. But if the print head was stuttering what might be the cause and how might I change that? I'm using the 4.2.7 silent board and my sd card should be fast enough. Thanks.

[MariMakes 192]

Hey @PeterPan,

 

Welcome to the Ultimaker Community 🚀

 

I agree with @GregValiant that it looks a little like Buffer Underrun.

This might be an odd suggestion but have you tried turning off you interruption recovery feature on your 3D printer?

Do you also see these artifacts if your model has a lower meshcount? Because your printer might be processing a lot of small line segments and having to think about it. 

[PeterPan 0]

Hello @MariMakes,

 

I have deactivated the power loss recovery for exactly this reason if that is what you mean. Is there any other interruption recovery that I should know of?

 

I have never looked at the meshcount. I always just import the stl from Inventor to Cura and that always works. Well, until now. Maybe I should look into that.

Which software would be the right one for adjusting the meshcount? I think Angus from MakersMuse uses MeshMixer, would that be a good one? I don't think that  I can do that in Cura, can I?

 

I have worked a lot with the firmware. Could I have messed up anything there? I think there were some buffer settings or something like that.

 

Thank you very much.

Edited October 17, 2022 by PeterPan

[MariMakes 192]

Hey @PeterPan,

 

You should be able to define the amount of detail when exporting your mesh in inventor. 
You can also try an online Mesh Simplifcation like https://myminifactory.github.io/Fast-Quadric-Mesh-Simplification/.

 

There are also other ways to reduce your buffer underrun like slightly increasing the Maximum Deviation setting or changes that are more specific to your printer since it seems to be your firmware that is acting up. 

[PeterPan 0]

Hey @MariMakes,

 

these ideas are all very interesting and I'm definitely going to try everything out.

 

Is there an upper limit of mesh size that I should stay under or does it depend on the object?

 

Could I adjust the buffer size or the number of linear moves in the planner in the firmware to deal with this problem?

 

Can you think of any other firmware setting that might affect this issue that I could change?

 

Thanks for your help.