Wheel inside a wheel ...

[Thaelin]

Hmmm, so does the Archimedes thing have a true circular path around a center?  Makes me want to try something if it does.

[sm0ky2]

At certain points yes, at others the path varies slightly from Pi
depending on the design of the contraption
And this causes slight friction and pressure on places.


Some designs are more Pi-ish than others.


A lot also has to do with precision, and clearance of the moving parts

[Thaelin]

Watched it more closely   in slow mo and it is really an oval path. Not workable for me. Onward.