Inconsistent Extrusion

[TheBrigandier]

Update: @vertigo235 set up a Discord server for this issue, if you'd like to discuss/work with people on the problem. Here's the link: https://discord.gg/hYUjSnW

This issue has been closed after the overwhelming amount of replies, tests, etc. If you are needing guidance, please refer to http://prusaowners.com/wiki/index.php?title=How_to_make_prints_better_on_the_mk3 and Prusa Support.

[HeySideburns]

Yes! This is driving me crazy as well. Thanks for isolating this more @ff8jake ! I've got a pile of calibration cubes printed with different slicer settings and was never able to make the issue go away.

[TheRedcoat]

S3d with a brim, slic3r without. john.n13

Here's an s3d version with fan turned off half way up wall - at the mark:

[TheBrigandier]

More examples:

[TheBrigandier]

Just want to add that I compiled 3.2.0 alpha as of today's commits with no change on this issue.

[TheBrigandier]

Just to highlight the problem only shows up when indirect light is hitting the print, here's a single wall test piece I just did with and without my phone flash:

[misan]

Not the single wall box, which I will try later, but one example of somehow irregular extrusion on my MK3 using 3.1.3 firmware version.

However, I reckon output quality was better when the filament was freshly opened.

[3d-gussner]

Did you try to calibrate your extruders? Which slicer did you use? Did you tried another slicer like Cura, IceSL-slicer, ideaMaker (all free), PrusaControl or different versions of Slic3r PE?
Did it change with the firmware update?

[TheBrigandier]

Did you try to calibrate your extruders? Which slicer did you use? Did you tried another slicer like Cura, IceSL-slicer, ideaMaker (all free), PrusaControl or different versions of Slic3r PE?
Did it change with the firmware update?

Extruder calibration appears to be spot on (single wall thickness matches Slic3r setting of 0.45mm precisely). I have been able to reproduce this artifact on both Slic3r and S3D. I am getting this issue on both 3.1.3 and 3.2.0 Alpha.

So far the only thing I have found that lessens the effect is cutting the flow rate waaaay back (70%) which gives horrible inaccuracy, or dropping temp to around 195 (from the default 210) and having to print very slowly, or turning the external perimeter speed way up and dealing with ringing. The lower temp works fine for single wall cubes, but it causes clogs on the higher speed movements like infill.

Could it be that the temp is too high for the slow external perimeter speed required to prevent ringing? I understand it needs to be up there to get the filament flowing at the fast rate, but it also seems to be extremely oozy out the nozzle at 210 when stationary. If lowering the temp ends up being the answer, then all speeds across the board would need to be dropped...

[jonbet83]

I’ve also had the same issues as listed about, just to confirm also... cura, slic3r and S3D all have the same results. So far I haven’t seen a print off a mk3 without this happening.

There is tons of pictures on Facebook to back this all up, it doesn’t matter what I try the issues remains. Just to Also make clear this isn’t material specific either, PETG is also as bad.

Thanks Jon

[mvasilakis]

I have also noticed this. I was convinced I didn't have my extrusion multiplier set right. I did calibrate my extruder and my single wall cubes were coming out .45mm ish. I assumed I hadn't dialed my slicer settings in but it's possible I am having a similar issue to OP.

[vanvlierden]

Same here: printed in vase mode on 2 mk3's. the red one on a pre-assembled mk3, the silver one on a self assembled kit. FW 3.1.3

[Panayiotis-git]

I own a MK2s Prusa printer and I can add that this is the case for my printer also. Only with ABS I have good results. The PETG produces the worst.

[misan]

I sped it up 1/3 to the top.

[RacingHell]

Could this really be adressed to the extruder stepper movement? Had kinda similar results on earlier firmware with 0.25 nozzle underextruding, but flowrate already was fixed. Otherwise the ominously „clicking back slapping extruder“ might cause this. 3rd mention I would have might be bad manufactured (concentricity) or dirty bondtech gears.

[TheBrigandier]

More pics from the forums. @josefprusa @PavelSindler @XPila