Archive: https://archive.today/fF0F3 From the post: >>If you want to work with robots you can do all sorts of learning with software and simulation, but nothing quite beats getting to grips with real machinery. That was the motivation for [James Gullberg] to build this impressive robot arm. Featuring six degrees of freedom, the robot arm is mostly constructed of 3D printed components. This let [James] experiment with a wide variety of joint and reducer designs for the sake of learning and investigation. The base of the robot uses a fairly conventional planetary gear drive, while shoulder and elbow joints rely on split-ring planetary gearboxes to allow for high torque density with regards to size. [James] implemented a neat sensing technique here, integrating alternating magnets into the output ring gear which are monitored via a magnetic encoder. The wrist joint switches things up again, running via an inverted belt differential.