Bulge when print reaches "solid" layers  

RE: Buldge when print reaches "solid" layers

Posted by: @flubber

@bobstro This is kind of what I had in mind. No supports needed and just a short section. I have had this type of shelf cause the issue.

Ah, gotcha. Inside surface features. Yes, that's straightforward. I'll add something like that to the thick wall test print.

Man, I hate waiting 90 minutes to see results!

RE: Buldge when print reaches "solid" layers

Posted by: @bobstro

Posted by: @drewread

[...] I wish you luck in your future endeavors.

Thank you for your invaluable contributions in helping other identify and address these problems.

These were not sliced with PrusaSlicer/Slic3r:

...and they do not exhibit the bulge that this thread is all about thereby further proving the point that it IS slicer related. They both have other issues though.

RE: Buldge when print reaches "solid" layers

Posted by: @drewread

...and they do not exhibit the bulge that this thread is all about thereby further proving the point that it IS slicer related. They both have other issues though.

Ah, so under extrusion corresponding to internal features is not relevant. Only over extrusion is to be discussed?

You inserted a comment into this thread asserting -- without anything I've seen in the way of supporting data -- that it's a PrusaSlicer issue. You've ignored evidence that other slicers exhibit similar problems relating to extrusion at on vertical surfaces at layers corresponding to internal features (which considering they use the same underlying technologies, is not surprising). You haven't provided any suggestions or data on which to test. After a clear explanation that -- regardless of what the underlying causes are, many of us are looking to improve print quality -- you insist on inserting responses that it's a PrusaSlicer issue and that you are content to wait until some greater power fixes the problem for you. Do you think you are being helpful? Is your goal to be declared right? The winner? Get all the Internet points? What exactly is your purpose here? 

RE: Buldge when print reaches "solid" layers

Posted by: @bobstro

Ah, so under extrusion corresponding to internal features is not relevant. Only over extrusion is to be discussed?

Yes Bob, you seem to understand that quite clearly. The post titled 'Buldge when print reaches "solid" layers' in relation to files sliced using PrusaSlicer and printing with a Prusa MK3 as per the first post on this thread is actually about a bulge that is created when the printer reaches a solid internal layer while printing an object that was sliced with PrusaSlicer while printing on a Prusa MK3.

It is you who have actually derailed this thread from it's original question.. for about 8 or 9 pages worth of attempts to fix the issue by tuning.

Prusa has seemingly acknowledged the issue exists within PrusaSlicer:

Posted by: @flubber

 

Interestingly Prusa support has sent me an email acknowledging an issue with Prusa Slicer and the developers are working on this problem.

"What you can still try with the current version and works for my colleague is changing the extrusion width in PrusaSlicer for all options to the same value (for example 0.45), even for supports if needed. In some models where artefact like this happed, it might help resolving this issue. Thank you for giving it a shot, I really hope it helps to improve the quality of your prints."

Posted by: @flubber

“But I have consulted your issue with my colleagues and it seems to be related to PrusaSlicer not the printer itself. Our developers are working on this and I really hope they improve the behavior in the future releases”

 

So perhaps if you want to solve the other problems that are at hand it may be a good idea to start a new thread and not hijack this one?

RE: Buldge when print reaches "solid" layers

Posted by: @drewread

Yes Bob, you seem to understand that quite clearly. The post titled 'Buldge when print reaches "solid" layers' in relation to files sliced using PrusaSlicer and printing with a Prusa MK3 as per the first post on this thread is actually about a bulge that is created when the printer reaches a solid internal layer while printing an object that was sliced with PrusaSlicer while printing on a Prusa MK3.

Did you actually read the 1st post in this thread? The 'buldge' is the symptom. OP was looking for assistance in dealing with it.

RE: Buldge when print reaches "solid" layers

Well let try and see if we can get a working functioning printer profile that produces good parts.

I for one can not live with the 'one day this might be solved'. If they are just changing the extrusion width internally. I have no faith that the update to fix this will be out this year and I will (mostly) quietly grumble about that. I am still very mixed on this printer, but I have voiced that already.

Everyone can contribute. Coming up with a test model to produce the current bulge and any others will benefit everyone.

I am as guilty of derailing and snipping at Prusa as anyone else (posibaly more so), but ultimately I am happy to put my time in to try and get this resolved to a point that I can print the items I want in PS and not have to switch completly to Cura.

Judging by the bug list https://github.com/prusa3d/PrusaSlicer/issues this is not going to be at the top.

RE: Buldge when print reaches "solid" layers

Posted by: @flubber

[...] I am as guilty of derailing and snipping at Prusa as anyone else (posibaly more so), but ultimately I am happy to put my time in to try and get this resolved to a point that I can print the items I want in PS and not have to switch completly to Cura.

Does this look good? I can make the internal ledges a bit longer or larger. I'm going to try a print of this using Prusa defaults angled at 45 degrees to see if XY orientation makes any difference.

Edit: 1h11m estimated print time.

RE: Buldge when print reaches "solid" layers

@bobstro

Are those two ledges at slightly different heights? If so yes.

Have you tried a print?

RE: Buldge when print reaches "solid" layers

Posted by: @flubber

Just printing another test.

Quick question: Have you tried changing the angle used for Print Settings->Infill->Advanced->Fill angle? I find myself using nice tidy numbers like increments of 45 degrees that, if aligned with the part layout, might influence results. This would make sense on squared parts, but probably not help much with your rounded pots.

RE: Buldge when print reaches "solid" layers

Posted by: @bobstro  I'm going to try a print of this using Prusa defaults angled at 45 degrees to see if XY orientation makes any difference.

For me, the bulging line goes all the way around but I mostly see this on round or symmetricalish objects 

We could always have a four-hour test if yours does not work 🙂

RE: Buldge when print reaches "solid" layers

@bobstro

I have not tried changing the fill angle.

RE: Buldge when print reaches "solid" layers

Posted by: @flubber

For me, the bulging line goes all the way around but I mostly see this on round or symmetricalish objects 

We could always have a four-hour test if yours does not work 🙂

Much as I hate to, starting with a part that produces the problem for you consistently is probably a better starting point. Any chance you could zip and upload that beast as an attachment? Are there specific parts where the problem is pronounced, or just around the rounded external perimeter? Maybe we can cut it down just a wee bit...

If you cut that external piece into quarters, does a single quarter exhibit the problem?

RE: Buldge when print reaches "solid" layers

Posted by: @bobstro

Did you actually read the 1st post in this thread? The 'buldge' is the symptom. OP was looking for assistance in dealing with it.

Yes, in fact.. I did. You have made my point for me. Thanks!

RE: Buldge when print reaches "solid" layers

@bobstro

Here is the pot base from one of the photos showing the issue. I can send you the file in any Fusion 360 format but here is the STL.

Have a look to see if this can be chopped down or incorporated into your model (If we need to)

Well that file type is not allowed. Hold on...

https://drive.google.com/file/d/1U9IyqXdBnbZI9N_x3imn6REqXQDNMkPA/view?usp=sharing

RE: Buldge when print reaches "solid" layers

Posted by: @flubber

[...] Here is the pot base from one of the photos showing the issue. I can send you the file in any Fusion 360 format but here is the STL.

Have a look to see if this can be chopped down or incorporated into your model (If we need to)

Hmm. It's showing 2h30m. That's not as bad as I thought. Before I get started, just to confirm. You're printing with:

• 0.4mm nozzle.
• 0.2mm layer heights.
• 2 perimeters @ 0.45mm.
• Default prusa profile settings for everything else.

Is that correct? Have you tried using a larger nozzle? The results might be interesting both to see the effect of different extrusion widths, as well as any impact reduced nozzle pressure has. And of course, it would print much faster!

Well that file type is not allowed. Hold on...

https://drive.google.com/file/d/1U9IyqXdBnbZI9N_x3imn6REqXQDNMkPA/view?usp=sharing

To upload/attach files, they must in a zip format archive.

RE: Buldge when print reaches "solid" layers

What about something like

1-hour 43 mins?

No flat wall though...

RE: Buldge when print reaches "solid" layers

Posted by: @flubber

What about something like

Does printing that show the defect? If that works, that would be great! I'd appreciate the STL or (better) Fusion 360 file to start with. It would be interesting to see what varying wall thicknesses etc. affect.

RE: Buldge when print reaches "solid" layers

@bobstro

I can print it off now if you can hold on for 1 hour 43 mins 🙂

Its a remix of this

RE: Buldge when print reaches "solid" layers

Posted by: @flubber

[...] I can print it off now if you can hold on for 1 hour 43 mins 🙂

Heh. I know the problem. Yes, if you could confirm it shows the problem, I do want to make sure we're chasing the same settings. When you're comfortable with it, I'll print it with the PrusaSlicer defaults for your hardware settings (nozzle size match) just to see if we can find a good baseline.

On thin walls, perimeters make a huge difference. On thick walls, infill probably has more of an impact. My own suspicion is that this relates to solid infill, specifically top solid infill on the internal "shelf". I'll be interested to see if those little notches do much. That's what I was trying to highlight with the my test part with the thick base. Other, possibly related problems that seem to pop up are a bit of over/under extrusion near the base beyond simple elephant's foot deformation. I'd like to develop a good test print that can help calibrate for all 3 cases:

1. Artifacts on thick vertical walls (thick enough to use infill) attributed to internal solid infill features.
2. Artifacts on thin vertical walls (thin enough to not be a multiple of extrusion width and possibly require gap fill).
3. Artifacts near the bottom attributed to bottom solid infill.

I'm thinking if we can do this, it will provide a common baseline for anybody fighting the issue, and very possibly help convey the issue more effectively to the developers. It's also a good exercise for developing good slicer profiles, and I'd like to take any lessons learned over to other slicers.

RE: Buldge when print reaches "solid" layers

I'm going to have to concede defeat on getting the issue to show up reliably with my test print. I've added the rear features and wall notches, and it's coming out evenly using the Prusa default profiles. At least I'm getting my good diagnostic lighting (aka. sunlight) back now.