Simple way to print in "Real" multi-color without MMU or layer height based changes  

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

Tried my first dual color prints with this method. For signplates, it worked much cleaner and easier than with my Palette 3 Pro. 

The problem of missing the M117 message can be overcome by using a plugin in Octoprint. There are multiple. I've used the   M117 Navbar plugin with success 

https://plugins.octoprint.org/plugins/M117NavBar/

This way my Prusa signals me to change filament and in the statusbar of Octoprint I can find which color I must load next.

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

This way my Prusa signals me to change filament and in the statusbar of Octoprint I can find which color I must load next.

Nice find.

For signplates, it worked much cleaner and easier than with my Palette 3 Pro. 

Pretty disappointing for something so expensive.

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

I am currently trying this with a Mini+ and the gcode M600 works fine. It's also nice to experiment with objects rotated by 180° so that the letters of a font get printed directly on the (smooth or powder-coated) steel plate or as last layer for different haptics.

It's a bit sad that all of this seems to be missing from Prusa Slicer's included functionality at the moment and changing materials (filament types) is apparently not as easy as merely changing colors (of the same kind of filament), since the profile settings appear to get lost (at least sometimes). However, mixing PLA and PVB is working fine since the temperature is identical except for the bed temperature which doesn't matter so much.

My biggest problem however is the purging process after a filament change. Sure, purging itself works, but right after the purging, even more material gets extruded and I have to grab this excess filament with tweezers exactly when the next layer starts printing.

How can I add an intro line / purge line after every filament change?

This would eliminate this issue and I can't seem to find a code (or even a setting) for a stacked intro line. Maybe I just missed it. A whole wipe tower seems to be absolute overkill and it's apparently buggy in Prusa Slicer 2.4.2 since no matter how small I set the width and the (idiotically placed setting for the) minimum wipe area, the wipe tower is always a super long object and I cannot reduce its size.

; intro line
G1 X170 F1000
G1 Z0.2 F720
G1 X110 E8 F900
G1 X40 E10 F700
G92 E0

RE:

As I described, just add as many skirtlines as you have virtual extruders (or a multiple) and hight of skirt up to the highest layer you do a filament change. This way the nozzle is primed on printing the skirt after every filament change.

If you want to optimize the result, open gcode in notepad++ and search for M600. Remove the first (and following T0), as you start your print with first colour inserted anyway. On next and all following M600, remove M600 (and following T...), go a few lines down and insert a line with "M600" after the first line with G1 X... (it is the first segment of the following skirt). So any ooze you miss to remove falls into the skirt, not the object.

You might add more distance between object and skirt in print settings.

Example for editing g-code:

M600 ;                              <== REMOVE !!!
T1 ;                                <== REMOVE !!!
M104 S230 ; set temperature         <== Edit temperature if needed
M900 K0.08 ; Filament gcode LA 1.5
M900 K45 ; Filament gcode LA 1.0
G1 E-1 F2100
G1 X159.205 Y59.709 F10800
G1 Z.2 F720
G1 E1 F2100
M204 S800
;TYPE:Skirt/Brim
;WIDTH:0.42
G1 F1200
G1 X172.958 Y59.711 E.43122
M600  ;                             <== INSERT M600 here !!!
G1 X173.631 Y59.815 E.02133
G1 X174.32 Y60.065 E.023

As you also can see, there is an M104 nozzle temperature command after the toolchange (here "T1"). First colour is T0, second T1 and so on. If nozzle temperature is not set correctly for the filament, you can change nozzle temp here directly (or add a line with M104 S... if it is missing).

A bit of gcode editing is no magic 😉

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

Thanks a lot for the gcode!

If you want to optimize the result, open gcode in notepad++ and search for M600. Remove the first (and following T0), as you start your print with first colour inserted anyway.

You are so right about that! I already removed the first M600 since it's indeed annoying that it is getting placed there.

A bit of gcode editing is no magic 😉

Yes, but I still need to learn (more of) it and this is basically exactly how I learn it. So thank you again!

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

@vintagepc
how to make separate G-Code files.

with bed leveling ?

RE:

I find this extremely interesting, I downloaded the profile and the test STL files and I understand the usage concept.

Has there been any major updates/revelations since as was originally posted? The blog post on the ops website is from 2020.

Mainly am curious if there is anyone out there using this method to print flush logos embedded in complex parts or is this pretty much limited to simple, flat objects like signs/badges etc.

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

i've been wanting  to try this method out but i cant download the profile. Nothing happens when i click on it. is there any other direct link that i can get if from?

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

Just tried, still works fine. Maybe try another Browser..

RE:

You can print anything you like.  It is just a questions of how many manual color changes you are willing to do...

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

Forgive me for being late to the party on this, but I have a Mini+ and am trying to slice for a relatively simple multi-material print that has mid-layer color changes. These are the steps I've done so far...

• Open PrusaSlicer
• Navigate to Printer Settings --> General
• Change Extruders to "2"
• Check "Single Extruder Multi-Material"

I then return to the "Plater" tab and add and slice my object. In the preview view, the multiple objects are assembled and look exactly as I would like them to print. But when I export the gcode, there are no M600 color changes in the file.

I'm fine with doing the color changes and purging manually the same way as I can when changing filaments between layers, but I can't figure how to slice with the color changes appropriately inserted to go through that process.

Feels like I'm missing something simple -- does anyone who is familiar with this process have any ideas? Thanks!

3mf

@nightengale

Without seeing 3mf-file I am just guessing here 🤔 
After loading stl you must assign filament to your different parts....

Save, Zip (<- Important), and upload 3mf-file 

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

Thank you for the response! Good point, I had already assigned the different parts to different extruders.

I figured it out late last night though... Hopefully posting here will help someone else at some point. Adding "M600" to the "Tool change G-Code" resolved the issue and it's mostly working properly. Only challenge left is there is a little bit of extra PLA that leaks out between the filament change and resumption of printing. I think I saw a fix for that somewhere, but am going to have to back and find that solution again...

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

One more question -- the "virtual" second extruder is working fine, except for right after changing filament. During the first little bit of printing it does after a filament change, its as though the extruder is not fully charged, and it doesn't extrude for a few seconds.

Has anyone else experienced this, and is there a fix?

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

Posted by: @oliver-andre

As I described, just add as many skirtlines as you have virtual extruders (or a multiple) and hight of skirt up to the highest layer you do a filament change. This way the nozzle is primed on printing the skirt after every filament change.

If you want to optimize the result, open gcode in notepad++ and search for M600. Remove the first (and following T0), as you start your print with first colour inserted anyway. On next and all following M600, remove M600 (and following T...), go a few lines down and insert a line with "M600" after the first line with G1 X... (it is the first segment of the following skirt). So any ooze you miss to remove falls into the skirt, not the object.

You might add more distance between object and skirt in print settings.

Example for editing g-code:

M600 ;                              <== REMOVE !!!
T1 ;                                <== REMOVE !!!
M104 S230 ; set temperature         <== Edit temperature if needed
M900 K0.08 ; Filament gcode LA 1.5
M900 K45 ; Filament gcode LA 1.0
G1 E-1 F2100
G1 X159.205 Y59.709 F10800
G1 Z.2 F720
G1 E1 F2100
M204 S800
;TYPE:Skirt/Brim
;WIDTH:0.42
G1 F1200
G1 X172.958 Y59.711 E.43122
M600  ;                             <== INSERT M600 here !!!
G1 X173.631 Y59.815 E.02133
G1 X174.32 Y60.065 E.023

As you also can see, there is an M104 nozzle temperature command after the toolchange (here "T1"). First colour is T0, second T1 and so on. If nozzle temperature is not set correctly for the filament, you can change nozzle temp here directly (or add a line with M104 S... if it is missing).

A bit of gcode editing is no magic 😉

That's an awesome trick, thanks a lot! I tried to copy the purge line commands from the beginning right behind the M600 command, but wasn't able to get it right. After the filament change, the extruder always went right into the middle of the print, bumped one time onto the first layer, left some debris there and then went to the purge spot.

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

Hi all,

I'm new to 3D printing but I need to print two colors in the same layer, as per the subject of this thread.

With 10 pages of posts, Gcodes modifications and other 3rd party softwares, I become lost.

Can anyone help in posting here in a succinct and clear way, a step by step guide about what one needs to do to successfully print two colors in one layer with just one extruder?

I use only FreeCad, Prusa Slicer and MK4 printer for all my projects.

Thank you very much in advance.

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

Hi all, 

Looking at some videos on YouTube helped me to fully understand the process, so please ignore my request.

Posted by: @rui-guerra

Hi all,

I'm new to 3D printing but I need to print two colors in the same layer, as per the subject of this thread.

With 10 pages of posts, Gcodes modifications and other 3rd party softwares, I become lost.

Can anyone help in posting here in a succinct and clear way, a step by step guide about what one needs to do to successfully print two colors in one layer with just one extruder?

I use only FreeCad, Prusa Slicer and MK4 printer for all my projects.

Thank you very much in advance.

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

Hithank you for your article.

In your article under Advanced: Printing with more than 2 colors you write that you can enter/change the filament color in the information.

Unfortunately I can't find such information in my Gcode, why is that?

• M117 change to 1 red
• M117 change to 2 black
• M117 change to 0 yellow
• M117 change to 1 red

Posted by: @rainer

I've been working on creating a printer profile for the MK3, that allows to print in "real" multi-color without a MMU or any other Hardware modification.
This will allow to change the color in the middle of the layer, (not like the "ColorPrint" method where one layer was always limited to only one color)

(every print in this pic was done with only 2-5 filament changes (2 for 2 colors, 5 for 3 colors.. The colored part goes over just 2 layers)

This profile has 5 "virtual" extruders and the filament changes will be implemented via M600 as part of the "tool change".

You can actually print anything a MMU could print as well, but obviously it works best where you have only a small amount of filament changes. Everything in the above picture was printed with a 3-5 filament changes which can easily be handled manually.

I wrote full instruction for this and you can find all info + the required download on my Blog:
https://schlosshan.eu/blog/2019/03/02/prusa-i3-mk3-real-multicolour-prints-without-mmu/

it is actually quite easy to do, so go and try it out.
If you have any questions or feedback, let me know.

Rainer

RE: Simple way to print in "Real" multi-color without MMU or layer height based changes

hello so far i was using with my mk3 fmw and printer but not i am on  MK4 and got issue even it's recognize the gcode is not compatible and i say print it whatever

any idea where the Gcode is wrong !!

RE: New Simple way to print in "Real" multi-color without MMU or layer height based changes

How about just editing the gcode in notepad ++ I have experimented with this and it works well it is just super tedious so you save your gcode with as many M600 colour change commands as you like and then you open the gcode in notepad ++ and edit it at whatever spot you want you will throw in the following lines of code. 

;CUSTOM_GCODE

M117 Change to Red gold

M600

G1 E0.3 F1500 ; prime after color change

You then save it as a .gcode file the file type will say .*txt this is ok as long as your file name says .gcode at the end of it