Multi-Color Drawing / Plotting

Long time DIY CNC hobbyist and I’ve had my Onefinity up and running for a couple weeks now. Mostly just to see if I can do it, I want to plot some huge wiring diagrams, so I’ve been playing with ways of attaching a bunch of clicky-top pens to the machine and bumping them into a fixed post to select which one to draw with. It’s still rough, but as of tonight, it is basically functional.

The plastic bits:

G-code generation library: (Handles the pen changes among other things not related to this projects)


  • Moving the fixed post to the right-side Y-rail to support multiple rows in the pen magazine as well as getting out of the way of homing.
  • Support for full-size (current are UltraFine) clicky-top Sharpies – will require rework of the magazine.
  • SVG support in pygdk…or figuring out how to inject pen changes into Inkscape’s gcode generation – haven’t played around with that at all yet.

That is an innovation use case for the 1F. Apart from the software, do you have any examples of the hardware side of this project that you could share? I would enjoy seeing any progress you have made.

The hardware consists of two pieces, both of which are designed in OpenSCAD:

Magazine that holds the pens:

Static arm/post for the clicky-tops to run into:

(There are printable STLs in that directory as well)

In the current incarnation, the arm attaches to the left side of the X-rail and lines up with the outer row of pens in the magazine. You can access the leftmost three pens, but cannot currently access the far right slot due to the current post position at X=0 – you’d have to go to X=-15 or so to get that far right pen – easy enough to fix in a future incarnation of the arm.

You also have to home the machine before loading the pens or else the pens will crash into the post during the homing cycle.

Ultimately, I’ll be moving the arm/post to the front right Y-rail to address the homing issues as well as allowing addressing multiple rows of pens. My end goal is to be able to carry the 8-pack of UltraFine pens and 12-pack of markers at the same time – 5-rows of 4 pens in the magazine.

There are a bunch of short videos going over the hardware iterations here:

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Thank you for sharing your work - I never would have found it otherwise. I very much like what you have designed - simple (not a negative comment on the work that has gone into it) and functional.

I have plans to design and cut parts that would benefit from assembly labels/codes, and this system would work well.

I am using the Masso G3 controller, which has several options to set up a variety of tool changers and configurations. I can see your hardware integrating easily with my controller - a good thing since software is not (yet?) a skill I have.

Thank you for the inspiration.

Simple is very much what I was going for. I’ve seen a lot of DIY changers with various holders and racks and things and I wanted to minimize the number of moving parts and opportunities for error.

I’m interested to see what you come up with for your application.

Got multi-row pen addressing working tonight:


…and finally drawing something worth looking at…


This is an awesome project!


This is absolutely amazing! Do you mind if we share this on our socials as well?

Be my guest! I’m loving the machine – it’s an awesome platform to build on. I just got my spindle in to start playing with what it was made to do and I’m rolling around ideas to do 3d-printing as well.

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Mind blowing. Awesome work. :clap: :clap: :clap: