SpiRobs: Robots inspired by logarithmic spiral

Looks cool.

I suspect the software is doing a lot of the heavy lifting, because the mechanism is (looks) quite simple.

Here are some flaws/potentially misleading features I noticed:

By design, the robot has only 2 I/O functions (3 in 3D), which are the motors on the strings. Thus it can't be any more capable than any other machine with 2 I/O.

In fact, the design is simply a function that maps limited 2d movement and grabbing onto 2 motors.

Pulling the strings affects it's tip first, so getting it into a specific position is a pain. Making an "S" shape, would require first rolling it all the way one way, and then unrolling it the other way.

In the video, they have the robot already setup in a specific position, and they don't show how hard it is to actually get it there. All the complicated moves (around rocks+drop off) are very specifically set up, and might be non-reversible.

The "contact detection" requires one of the strings to be fully contracted. And all of it relies on the manufacturing and environment to be consistent with minimal friction.

This robot is a bit like brain*uck. You can do stuff, but you need to do it in a bit of a roundabout way. Not to say that there isn't a sense of elegance to it.

Are the STL files available anywhere for printing ?