Additional nozzle sizes for MK4 + MMU3 needed

[thess]

Description of the bug

Current slicer profiles for MK4 + MMU3 (1.13.2) offer support for 0.4mm nozzle only. We need more nozzle sizes supported

Project file & How to reproduce

Selection "Configuration Wizard... -> Prusa FFF -> Original Prusa i3 MK3 MMU3" only shows 0.4mm nozzle option.

Missing alternate nozzle sizes.

Checklist of files included above

• Project file
• Screenshot

Version of PrusaSlicer

2.7.4+linux-x64-GTK3

Operating system

Ubuntu Linux 22.04.4

Printer model

Original Prusa i3 MK4 + MMU3

[rtyr]

Yes, 0.4mm is only supported nozzle diameter for multi-material prints, but you can use other diameters for single material prints (single nozzle prints are supposed to be sliced with standard MK4 non-MMU profile).

[thess]

Not a very encouraging answer... Seems like we lost a bit of desired functionality on the upgrade. Any hints as to whether this will change in the near future. If not, then this is indeed a step backwards. I guess we have some work to do ;)

[mmaschenk]

This is a terrible answer. The whole point of nextruder is being able to quickly change nozzle types. So using mmu3 means that goes overboard? Come on prusa.

[ZzetT]

As a "workaround", I did the following:
Go to the PrusaResarch.ini (in Windows it is located in C:\Users<user>\AppData\Roaming\PrusaSlicer\vendor)

Copy&Paste the whole block starting with [printer:Original Prusa MK4 MMU3 0.4 nozzle] ending with default_filament_profile = ...
Example for 0.25 nozzle:

• Change title to [printer:Original Prusa MK4 MMU3 0.25 nozzle]
• Change inherits value to Original Prusa MK4 Input Shaper 0.25 nozzle
• Set printer_variant to 0.25
• Replace all nozzle_diameter values with 0.25
• Copy max_layer_height values from the related simple IS profile i.e. 0.15 for a 0.25 nozzle
• Replace P0.4 in the start_gcode to P0.25
• Copy default_print_profile from the simple IS profile i.e. 0.12mm STRUCTURAL @MK4IS 0.25

Then search for [printer_model:MK4ISMMU3] and add all the nozzle variants you added e.g. variants = 0.4; 0.25

Keep in mind that if the configuration wizards asks you to update the profiles, the values will be overriden again (just click "Don't install")

OR if you trust my pre-configured blocks (for 0.25, 0.3, 0.5, 0.8):

1. In [printer_model:MK4ISMMU3] change variants to 0.4; 0.25; 0.3; 0.5; 0.6; 0.8
2. Add the content of MMU3_profiles.txt after the whole block [printer:Original Prusa MK4 MMU3 0.4 nozzle]:
3. Open the "Configuration Wizard" and you should see all profiles.

No guarantess that they actually work (but I tested the 0.25 profile successfully) .

[thess]

@ZzetT - Yes, I did essentially the same thing for testing and have done several successful prints with no MMU hang-ups. Glad to see another confirmation of the workaround.

[ccle610]

Thx for your Post, for me, it's working now . . . I took the lazy way, using the MMU3_profiles.txt

I wonder, there are so much more Information for MMU3 @ MK4, than for MK3.5, but finally, it works ;-)

[GraphicsWS]

MMU3_profiles.txt is working fine for me too. Thank you for posting the workaround.