r/Petoi

Turns out you don't need active adhesion (vacuum, electromagnets) for ceiling locomotion — passive permanent magnets in Quaddle open source robot's foot tips are enough, as long as the gait is designed for holding contact upside down instead of just an inverted version of the ground-walking gait.

The interesting part wasn't the magnets, it was the gait — same open source robotics platform OpenCat, same 4 servos, just a different motion profile. Planning to open source this gait's code before it ships too, so anyone curious can adapt it, not just read about it.

Anyone else working on non-standard locomotion modes (climbing, inverted, whatever) — what ended up being the hardest part for you?

Been testing how much mechanical diversity I can get out of Quaddle robot by changing the attachment instead of adding more actuators. Same 4 servos and the same OpenCat firmware the whole time — what changes is the attachment (3D-printed, mostly) and which gait is loaded for it:

- Biped: printed base clips on, switches to two-legged walking

- Tricycle: printed wheel mount + a bearing wheel, front legs go passive and drag

- Bar-spin: printed grippers clip onto a bar, full 360° rotation gait

- 4WD: wheel kit replaces all 4 legs, standard car driving

- Water-paddle: printed footpads, paddling gait (works, though we've sunk it twice)

This is pre-release — not in production yet, but I wanted to share this fun experiment since keeping the servo count fixed while switching locomotion modes was a fun constraint to design around. The gait codes and the 3D-printed parts will be open sourced.

Happy to go into Quaddle's gait/kinematics details in the comments if anyone's curious.