Dear Sir,
I followed your development steps and wanted congrats for your works and sharing’s. When you published the repository about CatMini I decided to test and made my own 3D printed frame and electronics because the biomimetics of cat appeared to me a good model too. Here is a short video of my version “Spring”, hope you will enjoy.
My hobby is also link to robotic applications and I did some robots of my own mainly focusing on alternative way of moving / interacting https://www.facebook.com/versatilerobot and try to share this passion to young's by involve into a robotic French association "Caliban" https://www.facebook.com/AssoCaliban/
I look forward seeing your next developments
Best regards,
VR
Because it looks hard find servo output shaft tooth dimensions I extrapolated by measurements. Attached is a drawing I did in case it would interest some of you. However, it may be good to distort it a little to get a best printing quality.
Here is a small improvement done on the thighs made by 3D printing including the splines of the Servo output shaft MG91 and wire attachment. It is replacing the cut PCB, servo horn, screws and cable ties.
Looks good and more esthetic.
I also admire the springs and I love the clickity-clack of the feet.