That’s Not a Filament Spool, It’s a Robot!

Transformers may not be what I’d deem high-brow entertainment, but the idea is pretty cool. Robots disguising themselves as mundane and inconspicuous everyday objects? That’s neat! Matt Denton proved how neat it is by building this robot camouflaged as a spool of 3D printer filament.

Denton tackled this project at the behest of Prusa. The robot looks like a 2KG spool of orange Prusament and would hold up to fairly thorough scrutiny. From the outside, there really isn’t any indication that it is anything other than a spool of filament. There is even actual filament wound around the outside that can feed into the printer for a test run. It is a bit like that Barbasol can in Jurassic Park being able to dispense shaving cream.

But that whole spool is really just a shell to house the robot. The robotic internals consist of a DFRobot Romeo Mini ESP32-C3 dev board, an IMU, an RC receiver, and a couple of geared DC motors with encoders. Those components all mount onto an internal frame with lithium battery packs acting as weights on the bottom to keep the frame upright while the spool rotates around it.

And here’s the trick: the black ends of the spool are wheels.

Between the weight of the batteries and orientation feedback from the IMU, the robot internals stay upright as the wheels rotate relative to those. Other than the fancy IMU math, movement is just like any other robot with two driven wheels. Turn both at the same speed and it will move in a straight line. Turn one faster than the other and it will turn.

This specific combination of clever engineering and visual trickery is very satisfying. I think you’ll agree and if you do, you can build your own Spoolbot using the code uploaded to GitHub and the 3D models uploaded to Printables.