Painted Color not working with MMU

[pherz1]

Version

PrusaSlicer 2.4.0 -Alpha 3

_Use `About->
Version 2.4.0-alpha2=win64

Operating system type + version

Windows 10 64 bit

3D printer brand / version + firmware version (if known)

Prusa MK3s+/MMU2s

Behavior

I posted this also in FB PrusaSLicer Users Group
I tried painting a second color filament on a Treefrog (stl from Prusaprinters.org) and then exporting it to my MK3S+/MMU2. I started the body in filament channel #2 and Painted the eyes in Filament CHannel #3.
It started printing the body successfully, but when it got close to the eyes (about 18mm up and changed filament, things went wrong. I tried multiple times.
Are you aware of a problem? Do you need more detail from me?
When I sliced it, it looked correct. But, the printing did not work as noted above

Project File (.3MF) where problem occurs

Treefrog 2 color.zip
If you want more information let me know soon, because I will be travelling starting 10/20

[BaconFase]

You have a couple areas on the mouthline that use filament 5. I can only assume that is what is causing the issues since you don't mention it like you do for filament 2 and 3. Otherwise you should probably elaborate on "things went wrong."

[pherz1]

I did not put any other colors or layers, other than the filament 2 & 3. Furthermore, I did not paint the mouth, only the eyes. I am starting my trip today and will not be back to my 3d printer for a week.. But, I will watch this thread.

[BaconFase]

I'm just describing what I see from your zipped file. There are at least 2 spots near the mouthline that are set to filament 5, or they were missed when you colored the green parts. If you did not plan for this and your printer has nothing in the filament 5 channel on your MMU, then once the print gets to this layer it will move to filament 5, find nothing, and the print will stall to a halt.

[pherz1]

[cid:D2235650-DB0A-40EE-A8F8-FB3593C7D600] Yes, here is a picture of 3 attempts. For some reason it loaded and printed some of the white. In one case it got to the red. But, I know I did not paint the white, fil 5. So, I do not know how how that got there. There was fil in each of the 5 channels Thanks, Peter

…

Sent from my iPad On Oct 20, 2021, at 10:46 PM, SomeoneElse58 ***@***.***> wrote:  I'm just describing what I see from your zipped file. There are at least 2 spots near the mouthline that are set to filament 5, or they were missed when you colored the green parts. If you did not plan for this and your printer has nothing in the filament 5 channel on your MMU, then once the print gets to this layer it will move to filament 5, find nothing, and the print will stall to a halt. [Untitled]<https://user-images.githubusercontent.com/62388268/138202441-1892b2ab-ee22-422d-ae78-f61b1b1a92bb.png> — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub<#7134 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AML4O3RI3GKHWBOAINDPHY3UH55JDANCNFSM5GGYRGEA>. Triage notifications on the go with GitHub Mobile for iOS<https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android<https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>.

[pherz1]

[hejllukas]

As SomeoneElse58 says before, parts of the mouth on that model are painted with the 5th extruder. These parts start to print at 16.92mm Z-height.

We haven't seen anyone else reporting an issue that the model gets spontaneously painted with some color/extruder without the user intervention.
So I think the painted areas with the 5th extruder arose by clicking on another mouse button (with assigned 5th extruder) by mistake or something like this.
It's also possible that you originally assigned the 5th extruder to the model in the right sidebar. Then you used brush or smart fill with the 5th extruder in the MMU painting gizmo, and after switching to the 2nd extruder in the right sidebar, you didn't notice that some areas left painted with the 5th extruder.
But this is just speculation, as no one else has reported a similar issue.

You can paint areas that SomeoneElse58 marked on the attached screenshot witch 2nd extruder, and then the 5th extruded won't be used. You can check which extruders will be used in the left top corner in the G-Code preview.

Anyway, your 3MF file should be printed fine if the filament is loaded to all (at least channels 2, 3, and 5 in the case of your 3MF file). If it doesn't print fine, it looks more like there will be some issue with the MMU2S unit, especially when it doesn't fail in the same place (one of the prints on your photos fails much later than two others).