Robotic arms and actuators are fascinating things to watch, and as popular among manufacturers as they are crucial to modern industry. [kthod2000] built their own design, which is based on parts salvaged from old CD-ROM drives.
The arm itself is made up of numerous components that appear to be 3D printed, with three main motors visible along its length. These appear to be the ejector motors harvested from several optical drives, which helpfully come with a threaded screw on the output shaft which makes them perfect for a linear drive application. Managed by a TMC2208 driver via a microcontroller, the ejector motors control the multi-stage movement of the robot arm as it moves up and down.
The intention seems to be that one of these three-level assemblies can act as a single finger. Combined multiple times, this could create something akin to a five-digit robot hand. [kthod2000] also did a lot of work on the software side of things that handles arm control. The kinematics can be simulated on screen in concert with the actual movement of the arm.
We’ve seen similar versions before, like this plotter built from scrap DVD players. They are a great source of quality electromechanical components for small projects, so it’s no surprise to see them working here. Video after the break.