
This pen plotter, held together with structural epoxy, is an amazing piece of engineering, and almost as impressive as a bridge made entirely out of Bondo.
[Brian] at the Rochester, NY hackerspace Interlock needed to build something for the BarCamp geek “unconference.” To lure BarCamp attendees over to the Interlock table, they needed a small tabletop device with whirring motors that was able to make some decent swag. Hacking together a pen plotter sounded like the perfect project.
The mechanics of the build were scavenged from old printers and scanners. [Brian] decided to use pin-feed card stock, so the take-up wheels from an old dot matrix printer was sacrificed as well. This paper feed mechanism serves as the Y axis, and the X axis rides above the paper on precision rods. The pen holder is supported by a tiny solenoid.
Things start getting crazy at the software level. grbl was loaded onto an Arduino with a stepper driver shield, and vector text drawings were printed. After a bit of live-action hackery, [Brian] figured out how to plot captured webcam images. OpenCV captures and does a trace outline. This is converted to vectors with autotrace, and from EPS to HPGL by pstoedit. A Python script then cleans up the HPGL and converts it to G code and sends it to the printer. Confused? So are we, so just check out the video of the plotter in action after the break.
Continue reading “Insanely Kludgy Pen Plotter Actually Works” →