Single Material Mode - MMU3 with Prusa Mk4  

RE: Single Material Mode - MMU3 with Prusa Mk4

Got there in the end!

You need to use the Touchscreen and the Knob together - it does not mention this anywhere in the manual.  Once you get the Select Filament Screen, Touch the single line on the left and highlight it (in my case "1.PC" below the GCodes Filament line, then press the Knob. This lets you select the correct spool on the right and press the Knob when you have selected the correct one.  It will now ask you if you want to replace the filament etc.  

I don't find this particularly intuitive and if you make a slip of the thumb and press the Knob at the wrong point it starts to print and then you have to go through the Stop and wait for it to unload cycle even though it hasn't started loading!

RE: Single Material Mode - MMU3 with Prusa Mk4

I was having issues with this too.  I just got my MMU3 for MK4 up and running and upon trying to do a single color print which was sliced using the regular MK4 0.4 with IS (non-MMU profile), I sent it to the printer directly via prusaslicer / prusalink by selecting the "upload and print" option in the slicer and it automatically started printing with the filament in slot 1 without asking me for any intervention.  

I manually stopped the print and restarted it from the printer itself since the file was now uploaded and at this point it gave me the option.  And I also had to use a combination of touch screen and knob to get it to print with the filament in slot 5, which was want I wanted. 

RE: Single Material Mode - MMU3 with Prusa Mk4

Posted by: @graemesmith1960

You need to use the Touchscreen and the Knob together - it does not mention this anywhere in the manual.  Once you get the Select Filament Screen, Touch the single line on the left and highlight it (in my case "1.PC" below the GCodes Filament line, then press the Knob.

You can also get to this point by rotating the knob anti-clockwise: from 'Print' to 'Filament' to 'Back' and finally to the 'G-Code Filaments' section.

RE:

Is this going to be the normal way to Select single color filaments? 

Or could this just be a "placeholder" method until the slicer/firmware teams get more customized in initial gcode execution?

I was expecting to see the MMU2s / MK3 style "select filament #" type menu. This new menu is slightly confusing, it is not very intuitive to "single color" mode options.

RE: Single Material Mode - MMU3 with Prusa Mk4

Slight addition to this discussion.

I used the MK4 - MMU3 profile instead of the original MK4 IS profile for a single color print and choosing the slot I wanted at print time.  At the filament screen, I used the above procedure to override the default slot that the slicer set in the Gcode.  This way I can use the MMU3 profile all the time.

RE: Single Material Mode - MMU3 with Prusa Mk4

That is A good idea, I ended up doing the same method, but pre-selecting the extruder before I sliced the model. Just highlight the parts on the bed, then right click them on the model menu, and select extruder #. The mmu will automatically select that extruder and go right to the print

RE: Single Material Mode - MMU3 with Prusa Mk4

It's easy to use the MMU that way as long as you only want to use 0.15 or 0.20 layer heights and PLA or PETG.  That's all that is supported in the MMU3 profile.  To use anything else requires a lot of custom profile work.  I've done that so I can use TPU and PC with the MMU3 profile but if I want say a 0.10 layer height with Ultra Detail using ASA then it just so much less effort to use the single mode Mk4 profile and manually select the the correct tool at the print start.

RE: Single Material Mode - MMU3 with Prusa Mk4

Guys,

Am I missing something or does this mean the only way to print single material is with an USB stick (except for the method mentionned by @reddadsteve)? Not to mention the utterly clumpsy method to select a filament.

Just upgraded my MK3S/MMU2S combo to MK4/MMU3, and I straight away sliced the sheep and printed it without any hickup trough Octoprint. Hurray I thought, if the more complex multi-material works so well, single material should be a breeze, as it was with the MMU2S.

When I send the sliced gcode to Octoprint and then start printing from there, the printer "air extrudes": no filament selected (not even filament 1), it just starts printing... air...
Again, am I missing something?

Also the Prusa MMU plugin in Octoprint, which allows to select a filament in Octoprint rather than physically on the printer seems not to recognise the MMU3 (yet)...

That was a huge cold shower after the initial excitement of MK4 and MMU3...

RE: Single Material Mode - MMU3 with Prusa Mk4

@jiheffe Slight update for how I use the MK4/MMU3.  I now use 'send to printer' in Prusa Slicer instead of using USB.  The MK4 starts the gcode and will go to the filament screen where I can choose a different filament than the Gcode specifies, if needed.

RE: Single Material Mode - MMU3 with Prusa Mk4

Posted by: @reddadsteve

@jiheffe Slight update for how I use the MK4/MMU3.  I now use 'send to printer' in Prusa Slicer instead of using USB.  The MK4 starts the gcode and will go to the filament screen where I can choose a different filament than the Gcode specifies, if needed.

This is Exactly what I have been doing 

RE: Single Material Mode - MMU3 with Prusa Mk4

This is what I'm doing as well.  And I have my printer setup through PrusaLink and Prusa Connect.  I don't use Prusa Link very often, but I do send jobs to my printer through Prusa slicer directly using Prusa Link when I'm on my home network as I think its a little faster than uploading to connect then downloading to the printer.  

Last I read, the MMU plugin for Ocotprint was still not compatible with MMU3 though the Dev was working on it.  May be worth checking the GitHub for an update: https://github.com/jukebox42/Octoprint-PrusaMMU

I'm also slicing single colors using the regular MK4 profiles (non-mmu) which will just start a print with whatever filament is loaded into slot one.  If I want a different MMU slot on a single color, then I use the MMU profile as @reddadsteve outlined above. 

Honestly, as Prusa Connect continues to evolve and improve, I've not been using Octoprint very much anymore.  I still have it setup so that I can access my camera and watch a live stream of the print in progress remotely, but outside of that, I don't use any other octoprint features anymore.  

I also have an ESP32 cam setup to monitor my print through Prusa Connect, but the lack of a live stream has prevented me from getting rid of octoprint all together.  

I used to use octoprint for everything back when I had my MK3s, but now I'm just finding less and less use for it with Prusa Connect.  It's not a direct replacement by any means, but it's definitely worth spending some more time looking at.  

RE: Single Material Mode - MMU3 with Prusa Mk4

Thank you guys for your replies 😎 

So I guess I should investigate Prusa Connect.

But even then, will I still need to go to the printer to select the right filament? Thats a bummer, as my printer is on a different floor! I used to fire up the printer and Octoprint remotely from my desk, then start the print and monitor it with Octoprint. I only needed to go to the printer when  the job was finished (at least until I have a robot servant 🤣 !).

Yes I've seen jukebox42 is working on the MMU plugin, lest see how it works out.

I guess for all jobs that require "standard" settings (PLA, PETG, 0.4 nozzle) I will use the MK4 - MMU3 profiles.

Thnx for your help 👍 

RE: Single Material Mode - MMU3 with Prusa Mk4

What I did was add a physical printer directly in Prusa Slicer.  I forget the whole process.  I did setup PrusaLink and Prusa Connect but I personally do not have any need for them now since I go directly from PrusaSlicer to the printer.

It all depends on how much remote functionality you need.

RE: Single Material Mode - MMU3 with Prusa Mk4

I figured out a way to print in single material with the MMU3 on on the MK4.  So you either have sliced the model with the MK4-MMU profile and preassigned a spool number, or you have sliced it with the MK4 profile and therefore not assigned a spool. Either way works. In all cases you will not turn off the MMU in the menus on the printer.

If you sliced it with a MK4-MMU then just place the color on that spool position and print it, and you dont really have control over changing it.

If you sliced it with a MK4 non MMU you can put the color on any spool position you like. The steps for the latter as as follows:

1. slice as MK4 (no MMU) in prusaslicer
2. put your color on any spool position and preload to MMU in the menu
3. This is the key step - next preload to nozzle in the menus, and say ok when prompted that the color coming out of the extruder is correct
4. Now just print the MK4 (non MMU single color model) file. Note that it incorrectly assumes spool #1 but don't worry, since it detects the filament is loaded already it will just use it since it assumes it is on a single color printer anyway.

RE: Single Material Mode - MMU3 with Prusa Mk4

I agree that works, but I find it so much easier to use one profile, MK4/MMU all the time and just select the filament slot on the LDC menu when prompted.

RE:

Yes, I figured that out !

My preferred way would be to go with the non-MMU way, as I did with my MK3S/MMU2S combo and Octoprint.

I would slice often used gcodes ans store them on Octoprint. When needed,  I would just start the print and the MMU plugin in Octoprint would pop up and allow me to select the right filament from slot 1-5, at the same time as the choice selection popped up on the MK3S display. Selecting the filament from Octoprint would dismiss the prompt on the MK3S display.

I would like to see the same flexibility in Prusa Connect. No need to preassign a slot in the slicer. Filaments' positions in the slots may / will vary over time, so next time you print a gcode, the filament needed may well be in a different slot. This is particularly true with Prusa Connect where Prusa gives us generous space to store gcodes for reuse later on.

This step where you need to be physically at the printer to do this "mapping" is the only bottleneck in a real remote workflow. It should be possible to do this mapping from within Prusa Connect.

Ideal solution:

1. Preload filaments on the MMU. In Prusa Connect tell what filament is in which slot. Not just PLA/PETG, but E.g. "Slot 1 : Prusament PETG Orange" - akin to Spool Manager in Octoprint
2. When a single material gcode is loaded on a MK4/MMU3 config, Prusa Connect presents the available filaments to choose from - akin to MMU plugins in Octoprint

Even better, a "real" Spool Manager tallying filament usage etc...

RE:

I use the same procedure as described above. Slice the model with the standard Mk4 profile - Load the gcode, prompting the MMU material selection screen - Use the touch screen to highlight the desired filament slot - Press the knob to confirm selection - Confirm filament change when prompted

It worked perfectly for me. The correct filament was loaded and unloaded after printing.

For a while now, maybe since the last update, the filament is no longer unloaded, but the LED screen is endlessly waiting for the loaded filament type to be selected, even though it should be known to the MMU3.

Any idea how to get back to the "old" behaviour with automatic unloading?

RE: Single Material Mode - MMU3 with Prusa Mk4

Thank you for explaining this with the screen shots!!!  I've been frustrated with this perceived loss of function for months and didn't know how to select alternate spools from printer or how to enable spool join.  Prusa should have done a better job of explaining this!

RE:

I slice single color prints with the standard single .4 nozzle profile.  Then I upload print through Prusa Connect and if say the Color I want to use is in slot 3, I go into spool menu, then load to nozzle and pick spool 3, then go back to print and it will have you confirm that its loaded and show in slot 1 and I just hit ok or print , cant remember but seems to work like a charm... other than today I tried the Spooljoin for the first time, was finally at the end of my first Galaxy Black filament, first empty spool ever ! ( had MK4 for a year now)  with article below and one youtube clip about the XL it would have been worse to figure out.  I had another color in #1 and did not want to unload,  #2 I had the almost empty Galaxy Black, #3  a new Galaxy Black.  I loaded #2 to nozzle, showing on the screen it was #1 and then I spool joined 3 to 1 that was really 2.  When it was time to change it unloaded #2,  then tried to load #2 again , after shearing off end of filament and some manual tube swapping on the MMU3 , I got it to continue.  The info I saw I should have known better, the new spool needs to be right after the almost empty one in # 2 sounds like and almost empty in # 1 is how I understand it?  I will try again with large piece of PLA so it will run out fast and see if I can make it work as intended 

https://help.prusa3d.com/article/spooljoin-mmu2s_134252