[Solved] Help needed! Printing MM (PLA, FLEX)  

RE: Help needed! Printing MM (PLA, FLEX)

A little bit of update.

Tried setting 2 Extruders in printer settings, then set filaments per extruder accordingly and only after ticked setting `Single Extruder Multi Material`. Then I added Color change step on desired layer and sliced. Basically went the 2. route I described previously. As I describer color legend in slicer was showing some odd things and FLEX filament was with red flag but it sliced (with oddly very long waste tower).

I proceeded printing. First installed filament already was PLA so C1 went all in. On the desired layer it actually wiped it's nozzle, unloaded filament and asked to load next one. I loaded TPU and C1 asked which filament type I have loaded, so I selected FLEX and loading process continued without problem.

Print finished and here C1 started to act... It tried retracting filament too aggressively as if it was PLA in the extruder and on the display it was saying that it had PLA loaded, although on the color change I selected FLEX.

So the main question stands, is it correct way to print it? Or how should I print TPU on top of PLA or vice-versa without owning MMU. I'm lost

RE:

OK! After messing with settings, reading some internet and messing with settings again I have found answers I was in search.

So let's address all the questions

1. Setting multiple extruders without setting Single Extruder Multi Material won't set correct temperature. I tinkered with Prusa XL profile and what would you think, all temperatures are set correctly. I did check custom G-code and only found that for XL there's a code M109 to set target nozzle temp on the tool change, but at the same time after toolchange code there goes filament specific start G-code which sets heatbreak temp and after that additional M109 is emmited

   M900 K0 ; Filament gcode
   M142 S36 ; set heatbreak target temp
   M109 S230  <------ This is added once again

   For the C1 and same material only filament specific code is added but M109 is not called
   So to mimic same behavior for Core One filament start g-code can be altered adding to the end this template

   {
   if layer_num == 0 then
     "M109 S" + first_layer_temperature[current_extruder]
   else
     "M109 S" + temperature[current_extruder]
   endif
   }

   This results in correct temperature readings on temperature tab in slicer.
   Still don't know if it is a bug in the slicer or it just knows that C1 shouldn't have several physical extruders (Then this does not make sense in the light of upcoming INDX for C1).

2. Now main question, C1 - MM. It is easier than it sounds (God, if only that info would be more visible 🙂 )
   Ok, short answer: You need to toggle Single Extruder Multi Material option after setting "extruders" count. At least this will "fix" the issue with the temps (M104 code is called before tool change and unload).
   Long answer: It's complicated (I did not find HOW TO\Manual on MM prints out there, and not much info was given in different threads, posts whatsoever). So, you have couple of options how to print with MM and how to set up your presets and slicer.
   1. The most obvious thing to do (most of the places talk about this) is to select a layer where you are starting to print with another filament, right click on layer selector and add color change M600 G-code. This will add needed color change code and produce this odd legend of color changes like shown in my original post question number 1
      
   2. Easier but not so obvious (at least for me) option is to got into printer tab (where you have selected extruders count). Make copy of system preset, set your "extruder" count, toggle SEMM option and go to "Custom G-code" menu. There you need to scroll down to "Tool change G-code" section and add this line

      {if layer_num >= 0}M600 ; change to filament for extruder {next_extruder + 1}{endif}

      Maybe you can use just plain M600 code without IFs. Thanks to 3DesignsCH for his tool box printable where I looked it up.
      Adding this code to the "Tool change" section will add M600 code on all tool changes where needed and you won't be needing to add this manually on all layers, also you will be able to print with different colors on the same layer (manually adding color change gcode will only change color on the layer change)

3. And lastly how to deal with some filaments missing when SEMM option is toggled. As I tinkered with XL printer presets I saw that FLEX is awailable there. but not for C1. I believe this is the case for when you are using MMu3 which has problems loading FLEX materials, but as in my case I am not using MMU and changing filament by hand I don't see any problem why it would be inaccessible (Maybe there should be properties in slicer to differentiate when SEMM is for og C1 and when SEMM is on with MMU3 C1).
   So to be able to select FLEX or any other material that is not visible when MM option is selected you need to alter some filament properties.
   1. Make a copy of Generic Flex, or any other FLEX material that you have
   2. Open "Filaments" tab and go to "Dependencies" section.
   3. In the "Compatible printers condition" find `and ! single_extruder_multi_material` section and delete it.
   4. Save, et voila. Now when you select your MM printer profile, filament will be available.
4. Using same trick in point 3 you can also add said filament to MMU3 selectable filament. Just change `printer_model=~/(COREONE)/` part to `printer_model=~/(COREONE|COREONEMMU3)/`. But do it on your own risk, only if you are certain your MMU will handle changing to\from FLEX. I have sometimes problems unloading TPU from Nextruder, probably when ramming and unloading it does not want to eject TPU back down the PTFE tube and jams in Nextruder (Probably need to try nextruder sensor mod with magnets and change the first sensor to the C1+ variant)

To sum it up, all my questions and problems were resolved. There is possibility to print PLA\PETG + TPU with manual material changes. Also there are pretty easy ways to achieve it without constantly adding color change G-code on layers, rather be it automatic (Thanks again to 3DesignsCH for his project where I found the solution).

P.S. I am a bit sad I have managed to get all the answers several days after part in question was already printed.