One of the grad students in the lab I work at built a transforming wheel for a design project. To actuate, it had to be twisted from the side opposite the driving motor, and it involved dozens of joints as well as 4 friction-heavy sliding pins. The idea never ended up being fully realized.
I had some down time yesterday- so decided to take a crack at the transforming-wheel concept and 3D print my own design. My design uses 2 different contact surfaces, one for off-road, one for on-road. It basically swings open like an apple cut into 6 pieces.
Sometimes a smooth wheel surface is best when encoders are needed and the terrain is flat, other times you want something large and manly for getting over obstacles. Insert “why not both” meme here…
https://www.youtube.com/watch?v=tISH_5J7ETA