3D Printing in Color (using Prusa MMU2)

I am looking for advice on 3D color printing using a Prusa (Slic3r). I’m able to make 3D models and print them just fine. No problem.

But I am struggling with Sketchup to produce color 3D printable models.

With Prusa you design separate STL files for each individual color. Basically it is a set of nested 3D models with each assigned to a separate extruder/tool/filament.

The difficulty with Sketchup that I am having is shared surfaces. A surface can be assigned to only ONE layer or be in only ONE group. So if two colored sections are adjacent, the shared wall can only be assigned to one of them. That leaves the other color without a surface on that side.

So what is the solution to this?

How can I create a model where the surface belongs to both colors?

That would be two surfaces, one facing each direction. IF you had two extruded rectangles next to each other, each one would have all the geometry needed to close the shape, and each would need to be exported as a separate STL.

Difficulty arises when a shape is organic - say if you wanted a rabbit to have orange ears when the rest of the rabbit is blue. My solution is to model the rabbit (with ears), then separate the ears making them a group, and the rest of the head a group - then group both. Perform the separation using copy / paste in place, Please ask if you are unclear on this procedure.

I know how to do that. It’s tedious when you have many hundreds of individual pars on a board. They are separated by layer, but that doesn’t help.

The basic problem is that Sketchup doesn’t allow a surface to be shared. So if that surface is part of one watertight volume then it cannot be used by the adjacent volume.

I was hoping there was some Extension or other tool out there, perhaps one that could use face colors to move surfaces back and forth foe export.

I use the Chroma / Palette system, so the issue doesn’t exist - if it is a multicolour single print.

While interesting, it is not a useful or helpful comment.

Sorry, wasn’t meant to offend. I will rephrase and say, Have a look at the Chroma system, if you do a lot of colours on a print it might work for you.


Still not helpful.

I own a $1,500 Prusa i3 Mk3 with MMU2s. We’re committed to that machine.

There may be other systems out there with their own benefits and challenges. But those are irrelevant to the issue of solving this problem.

By the way, you might like using LED lighting that is 4100K color temperature, it is the best for rendering colors. <<- An example of a useful but utterly irrelevant comment that isn’t helpful at answering this question.

Does this mean you are attempting to separate geometry by assigning parts of it to different layers without creating groups or components first?

It would help if we could see an example of one of your models to help determine how to solve your problem

Yeah… sharing a model would help. Putting geometry on layers will not help. Faces that are “shared” between pieces need to existing in two different groups.