Hands On With Filament Splicing Robots

The future of 3D printing, it seems, is in multimaterial filament printers. The Prusa I3 multimaterial upgrade exists, and this weekend at MRRF E3D announced their amazing multihead printer. Multimaterial printing will get you mechanical parts with the properties you want, like wheels with grippy treads and strong hubs. It will give you easily removable support material. The most popular use, though, is bound to be multicolor prints. It’s easier to do, as you’re really only working with either ABS or PLA, and if you’re really clever, you can squeeze everything through a single nozzle.

While there are some very ingenious ways of printing in multiple colors of filament, one technique that hasn’t gotten a lot of attention is automated filament splicing. With this, a piece of software analyzes a model, and combines multiple spools of filament into one long strand. A machine that’s getting a lot of attention is the Palette+ from Mosaic Manufacturing. There were a few of these on hand at this weekend’s Midwest RepRap Festival, and here anyone could get a hands-on with this machine without spending $800.

When it comes to multicolor and multimaterial prints, the first question that comes to mind is the toolchain and the process of turning an STL file into a physical object. The Palette+ uses a piece of software called Chroma that takes STL files as its input. Each color in the object to be printed is actually a separate STL file, combined on Chroma’s build platform. The Charmander print shown above is actually four different prints; the white eyes are one STL, the orange body is a second, the yellow belly is a third, and the red flame on the tail is a fourth STL. In the Chroma app, these STLs are assembled, colors are assigned, and a file generated that’s stored on an SD card and shoved in the Palette robot. The Palette then assembles a custom length of filament with the right colors in the right places. Combine this with some G-code from your favorite slicer, and you have everything you need for multicolor printing with the printer you already own.

The results are fantastic, and the best I’ve ever seen from a multicolor filament-based printer, whether it’s a dual-extrusion head, Prusa’s Multimaterial upgrade, or a bizarre machine with multiple toolheads.

Of course, there are downsides. Because the Palette is designed for single-extruder printers, you’re not going to be able to combine ABS and PLA filament. Combining fancy engineering plastics and colorful PLA is right out. This is a machine that can only use one type of plastic at a time.

That said, we’re getting very, very close to an era of true multicolor printing. Of course, this machine costs as much as a good 3D printer, but if you just want to print some colorful blobs of plastic, I haven’t seen anything better.

27 thoughts on “Hands On With Filament Splicing Robots

  1. Why couldn’t the color data file be used to change extruder temperatures as the different filament types are coming down the pike? Sure, it’s not instantaneous, but it wouldn’t take much experimentation to find the optimum transition times for various combinations of polymers (along with other stuff like how long a section needs to be before it needs its own temp, etc). Of course, this all depends on the Palette being able to get the things to stick together into a viable length of filament…

    1. That might be the problem, how well does PLA bond to ABS for example.

      Once together on a part, they may be okay, but you’ve got a potentially fragile join in that interface of the two materials between the Palette+ and the hot end, and that needs to hold for that duration while the tool head is whizzing about with the previous material, then a little longer while the hot-end adjusts temperature for the next run of filament.

      1. Yeah, but, if they don’t stick together at all (or very well) then why would you combine them using a dual-extruder printer? Clearly, the hard and flexible plastics play together (e.g. the wheel with integrated tire) so it should work for at least a few material combinations. Also, since a purge is required between materials, the join needn’t be a simple butt splice (although other joins are obviously more difficult and use more plastic).

  2. There is one problem with the company…
    They are planning to protect their findings with patents.. So instead of going public, they are closing the technology (as 3d printing was closed source for 10-ish years)…
    It’s sad and it shouldn’t be encouraged, especially in community like this :)

          1. Agreed! For some reasons open source is a good idea. As it may help progress. But in the end, making your ideas public isn’t always the best business model. Because it simply isn’t fair to let some people do all the hard work (sometimes years) but when they make it open source the allow another “company” to takes those ideas, produces it and effectively steal all the profit and sometimes even credit by not mentioning the original design or designer(s)!

            Open source if fun, but don’t start screaming when somebody decides NOT to share his/her ideas. It is still his/her idea so in the end they should be able to decide what to do with it. Or don’t they?

            Open source is fun when you wrote a small program in your spare time and don’t have a way to commercialize it. In other words, it would end up in a closet and nobody would ever know you’ve made it. But when you make something for a living then why should the things you do automatically be public domain?

          2. Yup — still nice that someone points that out, since I might want to choose to support something more open (which I do!).

            My wallet, my decision.

  3. -Please stop taking the “hobby” prusa printer as example of innovation.
    -Multi extruder exist since years
    -all serious 3D printers come with, at least, a dual exturder
    -multimaterial and multi noozle is very good, multi color is a gadget for children
    -multimaterial on one noozle is laughable.

    1. multi color makes good sense for my projects. I tend to make boxes (openscad parametric models let me size them as-needed) and for labeling of the ‘things’ on the panel, I use raised text as the final few layers. to date, I print the panel in white and the raised text gets a few swipes from a black sharpie marker and that does the trick for cheap and mostly effective panel labeling. now, if you let me print those last few layers in black (or any color), I can really have a simpler process and better look. if its multi color, it does not even matter that it takes longer, if I can code some sections of the panel to make the UI grouping more obvious, by use of colors or shades, that would be great.

      not for kids. useful for UI things.

  4. I have owned a palette+ for a few months now, and it is amazing. I started out with a FFCP dual nozzle, but just couldn’t get the results I was looking for. It’s a simple ecosystem with great results.

  5. It’ll be nice when they figure out how to purge the next color in the infill area of the print. This would help maintain clear separation of the colors. I’d consider buying one.

  6. It will be interesting to see where this goes. It is one of those times I am glad to not be an early adopter. Don’t get me wrong, I like the idea of having one at some point and see their usefulness.

  7. I think the real problem is that the color is in the filament to begin with. In the injection molding industry we use natural colored pellets and then add the desired color during the melt. The real solution here might be injecting the color into the extruder and not changing filament at all. I think this splicing idea probably wont gain traction as it is too mechanically complex and is not adaptable between materials so easily.

      1. No, the way it is done in injection molding is that colored chips (a small amount) are mixed into the neutral chips (the bulk product) and melted together. If there was a way to inject some kind of dye (in this case a liquid or gel would work best) into the extruder you should be able to get almost any color kind of like an inkjet printer does CMYK.

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