[Jim Fong] sent in this demo of his version of the UHU servo motor controller. [Uli Huber] has actually shipped over 2500 controllers for the servo. He doesn’t charge much for the chips ...

It only escalates from here! Both of these disks go inside the motor. That is, you have to pry the servo’s DC motor apart, take its base with brushes out, then insert the encoder disks.