I have wanted to design my own servo arms for my robots without the need to attach the servo horns to them. With a 3D printer available I wondered if it was possible to manufacture hubs for the spline on the servo shaft. The problem was to know the geometry of the spline. I am not the only one to be frustrated about this it seems when I google on "SG-90 spline". Many have asked the question on forums but there hasn't been any clear answers on how the geometry of the splines look.
This is a companion discussion topic for the original entry at https://community.robotshop.com/index.php/blog/show/modelling-a-servo-spline