You'd be surprised what you can do with servos modified with encoders, setup with an industrial grade cascading control loop. First demo video below demonstrate

You'd be surprised what you can do with servos modified with encoders, setup with an industrial grade cascading control loop. First demo video below demonstrates threading a mechanical pencil lead in and out through the writing tip. Second video demonstrates a 187gram weight at the end of a 470mm long rod. Third video shows that the modification is now a quick fitting of some 3D printed parts to the servo motor axle and servo housing. https://www.youtube.com/watch?v=ECLrLupFW10 https://www.youtube.com/watch?v=_4mrb2T706s https://www.youtube.com/watch?v=Ctb4s6fqnqo https://github.com/adamb314/ServoProject