After many iterations for our Spot Puppy leg design, which we documented in the evolution of a leg design blog post, we have finally printed a set of four generation 5 Spot Puppy legs which we hope will be the final design. The legs are printed on an Ultimaker 3 and we are using metal geared servos to drive 3 points for rotation, two at the hip and one at the knee. The dual hip servos allow rotation both in the forward/backward plane as well as the perpendicular outwards/inwards plane.
The sequence of photos below show the assembly process for the legs from the original 3D print to first assembly.
And here they are fully built legs including servo horns and squash ball feet.
Spot Puppy Robot for PiWars 2020 