Full featured, miniature hexapod



What is Stubby?

Stubby is an evolving hexapod robot which I am making, with contributions from my 6 year old daughter (design, frame manufacture) and a co-worker (code review, debugging). I have long wanted to make a walking robot, thanks to shows like Stargate SG-1 (yay replicators!). While Stubby is not the same (6 legs vs. 4 legs, no wings, and of course there is the small part about not being able to turn raw materials into copies of itself... yet...), it has been a very entertaining and educational project to work on.

Stubby originated as a 2-DOF (12 servo) direct drive model which was supported directly by the servos (greatly limiting the size, weight, and shape). After quickly discovering the limitations of this approach, we changed it to use mechanical joints activated by push rods connected to the servos. The current version has a 3-DOF frame with radial symmetry and a full inverese kinematics engine.

It seems like everyone and their dog are making hexapods these days. A hexapod by itself is nothing to write home about. However, Stubby is unique in a few aspects:

This video demonstrates the different abilities of Stubby version 3, thanks to its inverse kinematics engine and 3 DoF legs.

The Evolution of Stubby

Version 1:

Version 2:

Version 3: