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

Posted by: @towlerg

 

One more question if I may, would it be possible to lay down the letters first?  that way you'd get as nice flat finish.

Layer 1: Red and yellow
Layer 2: Red                                                 (assuming yellow text on red body)

 

Hmmm  - you could lay down the letters first by placing the object upside down in prusaslicer, if I understand the question correctly.

Texy

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

@texy

yes sure that is possible i understood the question wrong maybe... i usually print the mutlicolor part of a sign on layer 1. no problem with that.
i thought he was refering to first  printing the inner part of a sign and then the surrounding part....

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

@texy

"Hmmm - you could lay down the letters first by placing the object upside down in prusaslicer" Yep, thats exactly my question. Seems to me (on the back of no experience with 3d printing) it would give a nice flat face.

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

@rainer-s

"i usually print the mutlicolor part of a sign on layer 1" Just to be clear, which way "up" do you print,  just as Texy posted or text on the last layers laid down? Sorry if this is obvious but I'm on the steep edge of the learning curve.

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

@towlerg

you can see it here:

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

@rainer-s

I realize that you must be getting pretty bored with my attempts to understand. I promise this is my last dumb question.

In the video (sorry I'd forgotten that and it show the orientation super clear) you do three filaments (yellow twice)

yellow - 2 layer body with void where text will go.
orange - 2 layers just text
yellow - all remaining layers

Using exactly the same .STL files, why not just do

orange - 2 layers just text
yellow - 2 layers with void where test is then all layers

and save a layer change?

I'm sure this obvious to you.

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

@towlerg

once again, this is how slic3r does it... but in this case it is quite logical...
the printer should never have to move "downwards" when printing...
so if you would print 2 layers of a color to start with, the printer would have to move downwards to then print the other color in the first layer..
that would impose the risk of coliding with the already printed structure....
My profile has no influence on "when" the color changes occur, but can just add the right gcode command to invoke filament changes, change filament related stuff like temperature etc.. the actual gcode  "order" is fully in slic3r
out of curiosity.. when will your printer arrive? what have you ordered?

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

@rainer-s

Thanks for taking the trouble.

I ordered a mini, delivery who knows?

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

Have any of you guys thought about investing in a MMU2S at all? I am contemplating, but I like the flexibility of the manual approach. Being restricted to four different filaments isn't what I am willing to put up with.

Unless you could also perform manual changes with the MMU, then it could be an interesting option. Especially when it comes to printing in color vertically.

What do you think?

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

@wieman01

I'm getting a mini so MMU isn't an option but seems like a lot of peep have bad things to say about it. Did you look at palette?

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

@wieman01

i've been thinking about it but decided against it...
Main reason is that i don't have a use case for multicolor printing where it would be needed.. the colored parts i print usually have the multicolor part on a flat surface like signs, panels etc.. and that can be achieved easily without to much additional work using a multicolor profile.
if you read only about experiences, usually it seems to be quite difficult to dial it in to work stable. Additionally it adds a level of complexity which is not always required/wanted
For the multicolor parts i print i usually have 2-7 manual filament changes which can easily be handled

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

Yes, if you don't have too many changes to deal with, then an MMU is an overkill, I agree.

I looked at the Mosaic Palette as well, but it's rather expensive if you plan to use Mosaic's entire ecosystem, plus I was not sure how it handles more colors than just four. It's a great system I believe that you can tweak to your liking, but given what I do in the non-commercial area it makes little sense. The MMU2S would do the job just fine.

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

OK, so I have this working well with a simple 2 colour design. Only one thing I haven't got right - the procedure states that the first filament to print is from extruder 1. So in my case this is grey filament, but when I start the print, it goes into the change filament routine straight away, even though I pre-load it with grey anyway. Once that is over with, it prints correctly, as this is only a bi-colour print it is easy to follow.

My mk3 is using the latest prusa 3.90RC release.

Texy

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

Have you tried only specifying two extruders? At least that way you'll see which extruder it wants to print first and you can compensate.

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

@texy

if i remember right, they changed something in slic3r that causes this behaviour... one additional initial color change to the starting color... i assume they implemented that for the mmu, but it affects us as well.
if you want, just remove the first M600 command from the gcode after exporting it to get rid of it...

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

@texy

Add this to the "Tool change G-code" section, this will eliminate the first annoying tool change forever:

; eliminate first tool change
{if previous_extruder != -1}

     <add your code>

     M600; change tools
{endif}

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

I love this and thanks for all your time, getting some really nice prints.   I was wondering if you ever figured out how to get it to display the color that was needing to be loaded?  I skimmed through this whole thread but most of it was over my head and didn't see anything where this was fixed other than a few post about testing.  Would love to get the fix  to make printing in more than 2 colors easier. Thanks

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

@johnday29

Thanks for the feedback.
we had a working modified firmware that did it, but did not have success to get the mk3 fw pull request through. looks like the Prusa devs did not want to implement the the required changes..
i have a version running which has a post processing script to automatically display a text file after uploading / exporting the gcode, which shows the required "order" of colors changes, but did not have enough time lately to clean it all up for publishing here..

So right now , the state is the following:
- you get a color change notification on the lcd which shows which color you have to insert next, but it is only visible for a couple of seconds

- the gcode contains comments to which color you have to change. ( can be extracted through a simple find command)

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

@rainer-s

Thanks, that is what I have been doing, my biggest problem, currently is i still have the mk3 not the mk3s sensor and get lots of false positives to change filament for runout instead of color change and can't always tell which one it is.  I may just need to buy the upgrade kit.  I love the sensor but it is a pain in the ass.  I am even getting false positives on black filament.  Again thanks for the great work it has made printing in multi color very simple and I can't thank you enough for that!  By the way any way to get rid of the, before first layer filament change with out manually editing the gcode? I tried to the modified gcode above but it didn't help.

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

@johnday29

to be honest... i disabled my filament sensor ages ago, never turned it back on 😀
i usually print rather small stuff so am not to worried about it.