While I’m making my way learning how to write proper modules for Robot Operating System, the rest of my SGVHAK compatriots have not been twiddling their thumbs waiting. Just like I went and built Sawppy as my idea of a cool rover project, Dave designed and built Mr. Blue as his idea of a cool rover.
All the blue printed plastic parts (which gave this rover its name) was designed in Dave’s preferred CAD software OpenSCAD. These pieces connect thin wall aluminum tubing that is very strong yet quite affordable. Making this rover a great exploration into a construction method quite different from Sawppy, where I designed 3D-printed plastic components in Onshape CAD and they connected Misumi aluminum extrusion beams.
Mr. Blue also expresses Dave’s ability to design and build electronics circuits. Where my Sawppy used serial bus servos, Dave has custom controller boards driving all the motors. There are two types on board: one drives a DC motor with feedback provided by optical quadrature encoders, the other drives a commodity servo motor but with precise position feedback via high-resolution magnetic encoders. In both cases, they feed into a 3D-printed gearbox for additional mechanical reduction.
Originally, the plan was to get Mr. Blue up and running on ROS, but Dave’s progress at construction was faster than my progress at learning ROS. As an interim solution, I added support for Dave’s motor control boards to my SGVHAK Rover software project. Now we have the same basic software running three rovers built with three different motor systems:
- SGVHAK Rover is running on RoboClaw controllers by Basic Micro.
- Sawppy is running on LewanSoul serial bus servos.
- Mr. Blue is running on Dave’s own custom controller boards.
We have quite a rover family going!