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.