It is a fun project to build a simple robot but, often, the hardest part these days is creating the mechanical base. [Concrete Dog] has a new open source design for stoRPer that uses a PC board as the base. The board has a Raspberry Pi Pico and motor drivers. The modular design allows you to add to it easily and use custom wheels. The video below shows some treaded wheels and some mechanum wheels with gears.
There are mounting holes for sensors and also a way to put another deck above to hold other circuits, power, or whatever you like. There’s lots you could do with this as a starting point.
Some of the parts are 3D printed, like the motor mounts, for example. This offers some flexibility on motors. There are even files for printing PLA wheels with TPU treads that look like they would work well.
The idea is that with a 3D printer and the PC board, you should be able to build something easily. Obviously, you’ll need to find options for motors. Still, with a populated board, many other parts are printable or easy to repurpose. For example, the video mentions using repurposed vape batteries as a power source.
We were a little disappointed there was no video of the little robots doing anything, but if you’ve programmed these sorts of robots before, you know they can be a lot of fun and very capable, especially with a Pi Pico on board.
You could argue that you don’t need four wheels to do this. That does robot
