Marker holder (for colouring feedstock)

by theorbtwo, published

Marker holder (for colouring feedstock) by theorbtwo Jan 13, 2011

Featured Thing!


We bought lots of white ABS with our shapercube.. Lots. But who wants
to print everything in white? After a while that got a
bit.. samey. So, an experiment, jam a coloured marker in the feedstock
inlet and see what happens. What happened was, coloured prints came
out. So the idea for the marker organ was born, a way to attached
several coloured markers to the feedstock, and pick which one, or
combination, is colouring the plastic.

This is the first attempt, a simple clamp over the feedstock which
holds a single marker against it.

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It is fantastic way to clog the nozzle

I didn't even see this, but we had the same idea. Mine holds 4 markers so you get really good coverage and color tone.


I thought it was the other way? CMYK+W mixing allows you to create green, but RGB mixing in the physical (vs light) would not give you yellow.


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Note: Please don't get discouraged by the wall of text. It's not that hard, I just wanted to document it fully!


Becuase there's no de-facto standard for the shape of markers, you'll
have to measure your marker and change the openscad model to fit.
Don't worry, it's pretty easy. If you want to be lazy, you can just
get the exact markers I used for this.

You can also change the size of the hardware you'll use to put it
together. Since it's currently set up for M6 bolts with square nuts
(because I had lots of them on hand), and because you need to modify
for marker size anyway, this is probably a good idea.

If you want to get the same markers I'm using, they appear to be
. Oddly, this doesn't match the number on the packaging, which says
"item #11090".

Open the .scad file in your favorite text editor. First, the bolt
size: change the line that says "bolt_dia = 6;" to list the diameter
of your bolts, in mm. (Don't add an extra bit for clearance; you want
one of the bolts to cut it's own thread as you put it in.) Make sure
you haven't accidentally removed the semicolon on the end of the line.

Measure the diameter of the part of the pen that you want to grip
(just above the actual tip), in milimeters and put it in where it says
"pen_holder_bottom_id = 8.5;". As above, make sure you
don't delete the semicolon. You want this to be a tight fit, but not
so tight that you can't get the marker in at all. If you get it wrong
the first time, you can always print another one.

Next, measure the length of the part of the pen that you want to grip
-- the part that is no wider then the pen_holder_bottom_id. You
should include space for the tip of the marker in this measurement as
well. Err on the side of making it shorter then neccessary -- it
needs to be long enough to get a good grip, but not so long as to keep
the tip from actually touching the feedstock.

Next, run openscad. Do a file/open to get your file, then
design/compile and render. (It's normal for that to take several
seconds.) Then design/export as stl, and do whatever you'd normally
do to print an STL file.


Clamp the two parts together with bolts, with your feedstock running
through the middle. Insert your marker and clamp it in using a bolt
through the side hole. Print something!


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Suljo on Sep 4, 2013 said:

It is fantastic way to clog the nozzle

ramai on Aug 22, 2013 said:

I didn't even see this, but we had the same idea. Mine holds 4 markers so you get really good coverage and color tone.


bstott on May 5, 2011 said:

Great - Good innovating. Thanks!

scocioba on Mar 9, 2011 said:

I've used Dry erase markers manually and no clog after a long time of printing. Works well.

hexitex on Jan 28, 2011 said:

This is really great but can anybody attest to their printhead being ok after a long run of this process? There must be a chemical reaction with the filament when two types of thing are being heated like this - there must also be a stable dye that doesn't change the abs properties too much?

ssd on Feb 2, 2011 said:

I've used shapries to color my parts from very early on...you can look at the pics I've posted in thingiverse...everything of mine not blue or red or black is sharpie colored.

Some inks do not dissolve well in the plastic. Sharpie ink in general works. All inks will saturate in the plastic, and left over ink accumulates at the top of the heated nozzle; if you stop coloring it, eventually the excess ink gets used up. If you want a quick color change, either avoid satur
ation, or back out the filament to remove the excess.

Some ink burns. The only way to tell is lack of colored filament, or strange colored, and no excess at the top of the nozzle...

I can't speak for dye changing the ABS properties, I haven't tested the resultant parts, and didn't notice any larg
e changes.

Glasswalker on Jan 26, 2011 said:

This is spectacular!

Any further thoughts on longterm implications for the print head? reccomended marker types that don't clog it up, or gas off too much? I would love to start experimenting with this, but don't want to damage my nozel (cash is tight these days, don't want to have to replace it lol).

Anonymous on Jan 20, 2011 said:

Great idea!!!

Just to give readers some more ideas, check this blog entry out also:

Kaipa on Jan 18, 2011 said:


very useful your tool! Do you have experience with different markers? I used some markers that blocked my nozzle (0.5 mm , Rapman) with black dirt after printing about houndred gramms of filament coloured with cheap permanent markers. I was not sure if the reason is the ink or the felt from the markers top? Tested also a "felt-remover" and nozzle blocked again. Any prefered Marker?



coasterman on Jan 16, 2011 said:

I'd love to print this after I'm assured it will not ruin my nozzle.

fabbing on Jan 15, 2011 said:

Awesome! It schould be a snap to add a second pen on the opposite side.

I'll try this with a copic marker, which has a wide tip and put a hole in it to paint the whole spagetthi

jgrout on Jan 14, 2011 said:

This concept is really cool. I love it. My questions is what are the long-term health on my nozzle?

Is there any concern about residue build-up or deterioration of the nozzle's performance? Any down side to adding this type of coloring?

I hope not because such a simple way to expand the printer's color pallette is fantastic. 8-)

jgrout on Jan 27, 2011 said:

I colored some short sections of white filament with a red sharpie and got smoke wafting out of the extruder but no color. If I buy a different brand will that change the outcome?

Anonymous on Jan 14, 2011 said:

Mechanic of the Ink Spiral:

One motor rotating a gear with 4 pens attached radially. A speed controller for the motor.
4 electromagnets to switch the pens CMYK ON/OFF.

Gil on Jan 15, 2011 said:

CMYK does not work like that. Mixing the paints would result in brown sludge.

eagleapex on Jan 15, 2011 said:

Seems hard to predict when a color would reach the nozzle.

defect on Jan 14, 2011 said:

Had to sign in to give props. This is a great idea.

Anonymous on Jan 14, 2011 said:

Excellent idea! Already thinking how to do it in a Dimension printer! Will try it.

A good concept to better fill the ABS with ink would be with 4 spirals around the filament.

Have no idea of how could be the mechanic of this, but should be similar to cable construction.

Large spiral means less ink, tighten spirals more ink, then you can just on/off the pen contact with filament. :)

jkeegan on Jan 14, 2011 said:

Waaaaaay back before I really had any experience with any real printers, I wondered why someone didn't create a Y-shaped nozzle that fed in ink or dye of some kind to color plastic.. Then I realized that plastic would back-out/escape through the dye side of the Y. Plus, my experience with switching from black ABS to natural ABS (and the long time between before it worked through the nozzle) discouraged the idea also.

I'm glad to see that die just on the outside edge of feedstock is enough to color the plastic! Any chance that we could see pictures of what some of the prints look like?

How long have you had to run the extruder when switching pens before the new color flushes away any remnants of the old?

ssd on Jan 14, 2011 said:






If I oversaturate the color, it might take 4-8 minutes to flush it (I usually build something small that I don't mind having strange colors). However, if you back out the filament and clip off about a cm, then it flushes much faster.

Anonymous on Jan 14, 2011 said:

This is excellent and now i am imagining things you can build and the colours to use :)

twotimes on Jan 14, 2011 said:

word of warning... Sharpie is stinky! :-E

feilen on Jan 15, 2011 said:

Haha, what's molten ABS then?

tbuser on Jan 14, 2011 said:

It would be awesome if someone would do something like this with multiple markers of different colors, each marker activated by solenoids connected to the controller that can turn on/off each color via a gcode. :)

jkeegan on Jan 14, 2011 said:

...and then code could be written that between color switches, the head would move to the purge area, the pens could be switched (like you say, just pull one back in its place and push another forward - it doesn't matter that one's further ahead than the other along the filament, as long as only one is touching), the extruder could purge enough plastic to flush out any mix of colors, then the head could move back to where that color should be printed on this layer..

ROTORIT on Jan 14, 2011 said:


You are a genius!!

I LIKE!! 8-) :-D =-X

This i s great work

still smiling :-D