Another Drawbot Uses A Pi And Web Sockets

There’s something about art. Cavemen drew on walls. People keep programming drawing robots. One we’ve seen recently is [Andy’s] Drawbot that uses WiFi and WebSockets to draw on just about any flat surface. What’s more, the Johnson County Library has a great write-up about how they built one and if you want a go at it, you’ll find their instructions very helpful. The video below is pretty inspirational, too.

What makes this build especially interesting is that it uses a drive system with two fixed points attached with suction cups.  There are a variety of 3D printed parts — some just for the build and some are older parts repurposed.

Since the device is made to move to different surfaces, the software needs to know the distance between the spools and also the position of the pen (the gondola). Once you have that set, an SVG file can start the drawing process. How far we’ve come since the caveman days.

The drive mechanism reminded us of some cable bots we’ve seen. We also recently saw a drawbot badge (no relation).

9 thoughts on “Another Drawbot Uses A Pi And Web Sockets

    1. If my quick research is correct, USB 1 and 2 are limited to 500mA on the power side, but surely less on the data side (20awg vs 28awg)… and a typical NEMA 17 stepper motor can pull 3x that (per phase)… BUT… on this project it’s probably not out of line… the motors won’t draw much current – the easy driver can only do 700mA per phase, and the load is extremely small. I’d say its a good design choice – long USB cables are cheap, readily available, and offer a solid connection.

  1. polargraph machines are tricky to balance and counterweight to get results like this, the servo that lifts the pen has a cable that drags the gondola off centre depending on XY location (see cable resting on base of the frame to limit this), I’d like to see one that fixes this problem.

    1. Perhaps this can be solved by replacing the cable with a battery and a wireless communication link?
      The extra weight of the battery can help to pull the gondola down vertically. I’m not sure if I have seen this
      implemented somewhere before.

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