3D Printing & Imaging Workshop
Automating a Filament Colorizer to a 3D Printer
Plotting Curves / Form Study, 2014
Plotting Curves / Form Study, 2014

Last year I worked on a project, “Plotting Curves,” to produce organic vessel-like forms that printed well without the use of support material. The goal with the work was to print big and iterate new forms quickly. All of the forms were printed on my large format Printrbot Plus and later on the Makerbot Z18 and were hollow with no roofs, bases, infill, supports, or rafts. The challenge when crafting the CAD in Rhino was to plot out profiles that could be revolved and lofted without going over the 45° rule as regards support material (i.e. anything less than 45° is likely to need supports). The resulting forms turned out to be aesthetically very exciting reminiscent of naturally occurring coral formations and so forth.

filament-colorizer-3d-printing-slower

In addition to working on forms that would be challenging for an FFF 3D printer to accomplish, I also “hand colored” each of them, drawing inspiration from Thingiverse user jamai’sFilament Colorizer” published in 2013. Sometimes I would color in a few feet of filament at a time, other times I would shade in as much of the roll as I could access at a given time with multiple colors overlapping and bleeding into each other. The results from these interventions were very successful with high contrast banding of colors highlighting the striations found in the layered plastic.

It did occur to me, though, that it would be interesting to try to control the application of color better. Could I draw shapes, a pattern, or even an image on a surface? After all, isn’t the horizontal movement of the extruder similar to the shuttle in weaving, each layer of plastic analogous to the woof (weft). Could the warp be unlocked by controlling the frequency of marks on a given portion of filament? That was the question — one that I wanted to start answering during my residency at the Maker Media Lab.

First working prototype
First working prototype.

One of the great things about the Lab is the collaborative atmosphere. My initial plan was to use Arduino activated solenoids to move the marker pen back and forth until Cameron Mira, one of the Maker Media Lab interns, pointed out that that would probably be a bad idea. Solenoids draw a lot of power, heat up, and aren’t generally that good for high frequency repetitions. So scratch the solenoids.

Cameron suggested I use Servos. Initially, I did not have much success with this either. It turns out that I was using the wrong type of servo (facepalm). Maker Media Lab speaker Sam Brown pointed this out and a quick change from continuous to standard type servo and we were in business with a little device moving the marker back and forth from 10° to 0° and back again with a delay of 1 second.

Rhino screenshot of first "Warp / Weft" CAD model
Rhino screenshot of first “Warp / Weft” CAD model.

From there it was a relatively simple task to mock up a prototype in Rhino using STL files from Thingiverse of a “Futaba S3004” by txoof and “Sharpie Fine Point” by beardicus to scale the soon to be 3D printed parts around. Amazingly, both the STL files were spot on and all my connections worked first time (this never happens). However, I did need to make some alterations with a soldering iron to the filament guide in order to get the tip of the marker to connect with the plastic properly. It’s not the prettiest mod but it got the job done at lot faster than printing a new piece entirely.

First print using "Warp / Weft" device
First print using “Warp / Weft” device.

At first, I ran it using a magenta marker (forgetting that the pigmentation would be very faint), then brown (which came out ok), and finally black which turned into a pale blue after printing. While the banding on the print is quite clear, I’m still a long way off from “drawing” on the surface. There’s a lot of irregularity in the mark making — partly due to the movement of the extruder creating fluctuations in the movement of the plastic through the filament guides. I may mount my next iteration either above the printer or design something that causes less friction on the line. I need to print some standard objects, cylinders etc, and increase the number of servo mounted pens to 3 or 4 for stronger color. Then, I’ll start working on the programming more — trying to dial it in and get some clearer results.

For now, this is a win. It is a step in the right direction and is a micro controller project I can sink my teeth into. Files for the STL’s, CAD and Arduino are posted here on Thingiverse.

[youtube https://www.youtube.com/watch?v=lLH2GXxwnaU]

15 thoughts on “Automating a Filament Colorizer to a 3D Printer

  1. I t would seem that you could get way better colorization by using 2 larger square tipped type sharpie markers (the type you use on a flip chart) and pincer movement on either side with 2 markers at once. That would deposit way more (and if you carve a groove into the tip it would likely get the sides, giving way more pigment)

    1. yes – i normally use the chisel tipped ones. it should be relatively easy to modify this to use them. cutting a groove in them is an interesting idea – i’ll try it out and let you know how it works.

  2. I would worry, though, about the fumes coming off of molten filament+sharpie juice. Even on a good day, the research is not in on the long term effects of being around the emissions from 3D printing (PLA plus the dyes in the filament). This setup also has the fumes form the sharpie itself, but then the fumes from the molten filament that has been mixed with sharpie dye that you would be breathing….

    1. This concern has been discussed before, although I can’t seem to find it. . The concensus was that modern day sharpie brand markers don’t have any chemicals in them that are hazardous when heated.

      1. Hmmm…”consensus” is hard to pin down on such a new field, when the possible effects are significant. I saw this article, that deals with deliberate inhalation (which is much more concentrated):

        http://www.teenhealthfx.com/answers/alcohol,+smoking+drugs/45680

        …but one of the concerns I would have is that if you are printing with PLA, PLA is more easily absorbed into the body than other materials…normally that is a good thing (and something for which PLA is usually lauded).

        But, if PLA is acting as a carrier for other more harmful substances, then what sort of absorption rate difference are we talking about?

        The answer is: no one knows…which is why 3D printers should have the most ventilation possible, and articles like this that talk about adding MORE chemicals to the 3D print process should OVERLY stress the need for more ventilation.

    2. it’s a good point. i don’t know. you’re right the data on fumes from filament is still a big unknown. i guess we could look at plastics factories where PLA, ABS, PET is used day in day out for at least some measure of exposure – but hard data on this would be useful. i’m not too worried about markers – i think most of the vapor / solvent evaporates quickly. that said i always work in well ventilated areas.

      1. You may want to use the rhino file and thicken the square base parts, I’m thinking they look thin.

  3. I have experimented quite a lot with filament coloring and I have found some time ago that the most interesting results are those where the filament is opaque and you can selectively color sides of the printed objects. This picture is with two colors and a PLA compound filament with ceramic powder, for a perfect opaque white.

      1. Hi Tom,
        I have done some research into this coloring systemand there are a few issues that need to be kept under control. First I made some search on the felt tip pens and only the permanent solvent based ones offer some good and intense effect.
        The kind sold for CD marking are OK, also Staedler permanent ones are OK.
        I splitted the tips with a blade so that the tip embraces at least one quarter of the filament (you can see it in the last picture,on the left pen).
        Then I worked on the persistence and delay between the coloring of the wire and the effective coloring of the printed piece. I found that there is some latence caused by the fact that the paint builds up inside the extruder tip sticking onto the brass surface until it is enough and flows out together with the molten plastic. This means a slow start and a slow ending of the effect. Retractions during the print also cause some mixing of sides because of the turbulence in the flow inside the nozzle.
        Last but not least, the opacity is the key to vivid colors: if you print with milky or translucent filament, you get hues that tend to be light and pastel like, unless you make several layers. If your filament is really opaque (mine was with a ceramic charge of about 45%), then the coloring is very strong. If you look at one of the pictures, you see that the color is just on the outside of the vase and the stuff in the middle is white.
        I add another picture I made to assess the effect of temperature on the final color and I can tell you that I had a LOT of surprises. In this case the PLA was neutral transparent.

        regards

        simone

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Tom Burtonwood

Tom Burtonwood is an artist, educator and entrepreneur based in Chicago, IL. Burtonwood co-founded Mimesis, LLC a product development company focused on 3D scanning and digital fabrication. He teaches at The School of the Art Institute of Chicago and Columbia College.

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