Lack Of Space Is No Longer An Excuse For Not Having A Pen Plotter

Pen plotters, those mechanical X-Y drawing machines that have in many cases been superseded by inkjet and other printer technologies, exert a fascination from a section of our community. Both analogue and digital machines are brought out of retirement for some impressive graphical effects, and we suspect that more than one of you wishes you had the space for one in your lives.

The good news is that you now no longer need room for a hefty piece of 1970s instrumentation, because the ever-inventive [Bart Dring] has produced a tiny 3D-printed plotter with an ESP32 at its heart. The ESP runs his ESP32 port of the Grbl firmware, and can handle a G-code file placed wirelessly upon the controller’s SD card.

The mechanism is particularly clever, using a single belt for both X and Y axes. The pen lift Z axis is a hinged design rather than a linear one, with a hobby servo doing the lifting. The hinge bearings are placed as close as possible to the paper surface to achieve an approximation to a vertical lift. You can see the machine in action in the video below the break, drawing its own self-portrait.

If you are a long-time reader you will recognise [Bart]’s work, he has appeared here quite a few times. His coaster-cutting machine and his CNC plotter badge are particularly memorable.

26 thoughts on “Lack Of Space Is No Longer An Excuse For Not Having A Pen Plotter

  1. Oh god no. They’re fun to watch, but I hope to never own one again. Having lived in an era where pen plotters were a necessity for business, I’m so glad to see them dead. Long live laser and inkjet.

    1. These are for artwork, not office work. They’re not printers, they’re drawing machines.

      The bit that I want to see that nobody seems to have done fully yet is make the jump from pens to actual art mediums. If I could stick a paint brush or an oil stick into the hands of one of these machines I think some really interesting art could be made. Even a syringe pump with paint in it could pull off some good stuff.

      I have seen a large format DIY wax printer (https://github.com/eumorpurgo/TextileDrawingMachine) for fabric dying. The Maslow (https://www.maslowcnc.com/) is essentially a plotter for wood. There are plenty of applications here as soon as you stop thinking of these as just old fashioned printers.

      1. “These are for artwork, not office work”. Word.

        We’ve seen a ton of painting/drawing robots, and some use traditional art media as well.

        https://hackaday.com/2013/11/26/robot-painter-works-like-a-photobooth/
        https://hackaday.com/2017/05/04/ancient-robot-creates-modern-art/
        https://hackaday.com/2012/01/27/jackson-pollock-is-now-a-robot/
        Plus a ton of graffiti bots, if that’s “traditional” yet.

        But besides art, small plotter machines are a gateway into the wider world of CNC. Step on in!

      1. Schools in Asian countries just love their handwritten assignments and other things of the past. Its nice to see students writing their assignments until they’re in middle school or even high school since they learn many skills from it, but it makes no sense for college students. Many professors in my univ wouldn’t even accept printed assignments, they wanted a handwritten assignment and that was it. This is mostly gone now, but in the 90s, this was still common.

        As a college student, I had to submit handwritten assignments of 10K words often. Writing such long assignments make your hands hurt, and after doing a couple in a single day, make you contemplate life. I would have used this plotter in a heartbeat if I had access to it, I mean, I AM doing the research, the handwritten text is just a delivery medium. It might as well be braille, it makes no difference.

        A significant demerit of handwritten schoolwork is that you also get judged by your handwriting. It was good for students who just wanted to get by with average grades, since they could just focus on making their handwriting neat and beautiful and get graded the same as someone who researched the topic for tens of hours, but didn’t write it in a good handwriting.

    1. Called a sharpie. Just double over the lines for better coverage. A fine tip sharpie would give good resolution.
      Beautiful project, I love the x-y design of the belts. I wonder it that geometry would scale?

      1. I’ve seen a large (10-15 feet across iirc) industrial case packing robot built with this concept. It was a vertical orientation instead of the horizontal shown here.
        But I’ve only seen 1. It might scale up, but doesn’t seem very popular.
        It was fun to watch though.

      2. What about the other way – paint over the board, and put a scribe in the plotter (which may need to be stronger to handle the side forces)? That would probably give finer lines and a better resist, and would probably go faster if the etched area isn’t very large compared to the filled area.

      3. Sounds nice but doesn’t work.

        The second pass of the Sharpie just re-disolves the ink from the first pass then pushes it along. I’ve actually had coverage get worse as I’ve made additional passes!

        I have managed to make some very pitted but usable breakout boards with Sharpie and Ferric Chloride or Muriatic Acid but only by using extra-wide traces to ensure that none of the many pin-holes will completely bisect a connection.

        I don’t think etch-resist pens are really all that usable of a solution.

        Maybe with paint pens?

  2. I used to work on commercial flat bed plotters the best pens are the Fischer space pen refills. They are gas pressurised and give a perfect line every time.
    It’s a nice build, the software and the esp32 platform is really interesting.

  3. It has come full circle. Now people are repurposing 3D printers to make pen plotters.

    The original 3D printers were just repurposed pen plotters. In the mid 90s we were experimenting with hotmelt glue and epoxy types to make these ‘santa claus’ machines. Never thought it would be significant to see one reverted back.

  4. If you poke around in old editions of the HP Journal, the magazine published by HP to describe research projects, there’s an issue that talks about work that wound up going into their inkjet printers. It’s been years since I’ve seen the issue, so I’m not certain exactly which.

    One project described is a pen plotter about the size of a deck of cards. One axis was handled by gripping the edge of the sheet of paper with little bits of sandpaper. The other axis was a steel measuring tape. There was a little piezo thingie to lift the pen. As it plotted, the sheet of paper would shuffle around and the tape wind in and out.

    The sandpaper gripping thingie became the grit wheels that HP used in their printers.

  5. I am really interested in this as a way of doing small-parts layout for cutting and drilling. I am not particularly great at laying out cut lines and hole centers and such, and remaking small parts 3 times to get the bolt holes to line up is pretty frustrating. A little pen plotter like this with a scribe or fine-tip sharpie seems like it might be a great solution for the quick transfer of technical drawings from the computer screen to the metal (or wood or plastic or whatever).

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