Arc welder creating artifacts in Cura

[PhilBaz]

I see the beauty of Arc welder but have had mixed results using it in cura. It mostly works great but has caused problems a few times.

Please see the attached images of 3 prints...the first two are sliced with different setting and using arc welder, the third has Arc welder turned off and the artifact is gone...ill attach the images as well as the G-code (github made me zip it). Is this an issue or do my settings need to change? I'm using settings very close to the defaults.

Thanks for your time and effort!

G-code.zip

[fieldOfView]

Is the order of the images correct? I see what looks like an underextruded horizontal line (outer wall) in the last two images, but not the first (it seems to be there still, but far less noticable). Is that the artifact I'm supposed to be looking at?

[PhilBaz]

The under extrusion line is the artifact, yes... Don't know if they are in order, but the naming of the images corresponds to the G-code names.

Thanks for the quick reply!

[PhilBaz]

PS...I can run the test again, or more tests if you think it was a fluke.....Also, there was a third AW slice benchy print which ended up with the same artifact.

[fieldOfView]

Let me ping @FormerLurker who created the actual magic that processes the gcode, to see if he has any ideas.

[seantapscott]

Thanks for sharing. Could be a lot of things depending on printer setup; filament out of round, sudden draft from an opened door, untuned pid values. Could you share filament brand and printer model, and any additional steps you've already taken towards verifying printer tuning and filament diameter accuracy?

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On Mon, May 3, 2021, 11:23 AM Aldo Hoeben ***@***.***> wrote: Let me ping @FormerLurker <https://github.com/FormerLurker> who created the actual magic <https://github.com/FormerLurker/ArcWelderLib> that processes the gcode, to see if he has any ideas. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#18 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AE5J4UDGFVBSOCJRFC3FEJTTL25WHANCNFSM44A6OFIQ> .

[PhilBaz]

Its an artillery X1 sidewinder...... Filament brand is Novofill, based on ingeo resin. I have my flow calibrated and get consistent high quality prints from the printer.

I sliced the benchy with Arc welder 3 different ways, and one additional slice was a duplicate of one of the initial 3, but without arc welder. All three with AW exhibited the same artifact. The one without AW didn't.

Im happy to run more tests. Any ideas?

[seantapscott]

G90 checked or unchecked? I'd also be curious what version of Marlin you're running. Again, just helping gather info so the troubleshooting can be quick and effective.

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On Mon, May 3, 2021 at 12:13 PM PhilBaz ***@***.***> wrote: Its an artillery X1 sidewinder...... Filament brand is Novofill, based on ingeo resin. I have my flow calibrated and get consistent high quality prints from the printer. I sliced the benchy with Arc welder 3 different ways, and one additional slice was a duplicate of one of the initial 3, but without arc welder. All three with AW exhibited the same artifact. The one without AW didn't. Im happy to run more tests. Any ideas? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#18 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AE5J4UEYRSM3EBAF6LYXK53TL3DSPANCNFSM44A6OFIQ> .

[PhilBaz]

G90 unchecked...Marlin FW bugfix version, March 21 2021 fw 2.0.7.2 .

No problem, i get it. And i'm happy to do more testing if you think there is something specific i should try. I appreciate your time and all the quick response.

Phil

[FormerLurker]

@PhilBaz, G90/G91 influences extruder should be checked for Marlin 2.0+. Can you attach both the modified and unmodified gcode (I read in your OP that you would attach these, but can't seem to find them) please? It may well be that having that option disabled is causing the problem, but it could also be issues with variable line width. Are you using Cura Arachne by chance? If so, I'm working on a patch that should fix any issues encountered there. I had to add some checks to break apart arcs if the extrusion rate changes in the middle of an arc. Without this, any differences in line width will be combined across the entire arc, possible causing under or over extrusion. I should be able to tell all this from the gcode. Feel free to create an issue in my ArcWelderLib repository as well, since this probably has nothing to do with @fieldOfView's awesome plugin.

[PhilBaz]

G-code.zip

I'll run another test with the option checked... Files are in the zip and labled.

[PhilBaz]

So the test with G90 enabled also came back with an artifact.

I sliced the benchy then saved one with AW on, and one without. No other changes.

One difference though, now the artifact is pushing layers out rather than in. Funny, what looked like under extrusion with G90 off looks like over extrusion now. You can also see the no AW version is pretty much flawless. And this slice is totally different than the ones pictured earlier. Ill attach pics and gcode.

F.zip

[FormerLurker]

Interesting, will look into this asap, and thank you for checking that out!

[PhilBaz]

No problem...thanks for the great tools!

[FormerLurker]

Update: After an extensive review and no issues discovered with the arc welder gcode, I ran the results through the inverse processor and can clearly see the deviations! This appears to be an issue with the arc interpolation algorithm's 'N_ARC_CORRECTION' value. When set to 0, the artifact vanishes. Need to look into it a bit more and figure out if there are any tweaks that can be done short of removing the small angle approximation. In other words, this is a firmware issue.

I have a hunch that reducing the maximum arc radius to something smaller (maybe 100 meters) would also fix the issue, but haven't tested it.

Will keep you posted.