If you keep up with the #BadgeLife, you’ve seen how creative people can be with the idea. If you go to a conference on, say, paleontology, the most exciting badge development you’re likely to see is lamination. But, go to a hacker conference, and people will be sporting a huge array of electronic gizmos as badges. Unfortunately, the vast majority of them are purely electronic and the only parts that could be considered mechanical are the power switches. If you’d prefer to represent a more mechanical profession, the DrawBot pen plotter badge is for you.
As with all badges, the two biggest constraints for DrawBot creator Bart Dring were size and cost. While many people push the boundaries of the concept, a badge does need to be wearable. It also needs to be affordable, and both of those constraints ultimately determined how DrawBot functions. Unlike a more traditional Cartesian plotter layout, DrawBot uses just two servos to move a pen on the paper, and a third servo to lift the pen. It works a bit like one half of a pantograph, and the servo positions translate to rough X/Y coordinates through a linkage.
That setup means the drawings are fairly crude, but it’s very compact and inexpensive. Each servo costs just a dollar or two, and the mechanical parts are all 3D-printed. An ESP32 development board calculates the plots and controls the servos, which means the total cost of parts to build DrawBot should be under $15. It draws on Post-It notes, so you can quickly start a new drawing, and stick your finished images wherever you like. It’s a great way to make all of your electronics-focused friends envious of your mechanical skills.