Elliot Madsen's Pen Plotter Upcycles an Old 3D Printer Into Something New — with an Arduino UNO Q

Mechanical engineering and computer science student Elliot Madsen has turned parts from a scrapped 3D printer into a two-dimensional pen plotter — powered by an Arduino UNO Q "dual-brain" single-board computer (SBC).

"While pen plotters are no longer used to plot designs because of the now comparable cost and much greater speed of inkjet and laser printers," Madsen says, in an about-face from their heavy use in the early days of computer-aided design, "they are an important part of engineering heritage. The point of this project was to build my own so that I could plot my own designs and projects that I am proud of in order to have permanent keepsakes from them."

The Madsen Pen Plotter's frame and motors are salvage, taken from a scrapped 3D printer. "Building the movement method as a CoreXY system seemed the most logical option as this would make the moving parts very lightweight and small as both of the needed steppers could be stationary on the rear of the frame," the maker explains. "The CoreXY system also allowed for the easy inclusion of a belt tensioning system in the front belt pullies."

The plotter's motors are driven from an Arduino UNO Q, the first in the Arduino UNO family to move from microcontroller development board to a "dual-brain" single-board computer design that combines both a Linux-capable application-class processor and a real-time microcontroller chip on one board.

"The ability to have both a Linux OS and an [STMicroelectronics] STM32 microcontroller on the same board was very attractive," Madsen explains. "The Arduino hardware simplified my power requirements as I could feed it the same 12 volts that I was giving my stepper drivers without needing a step-down [converter] like a Raspberry Pi would. Another advantage is that the prototyping shields that work for the normal UNO will also work on the UNO Q."

A solenoid provides a pleasing "clack" when the pen is lifted and dropped onto the paper, mounted to a brass and aluminum mount to double as a heatsink. Fans on the underside of the print surface pull a vacuum, providing stability, while an Arduino sketch running on the microcontroller core of the Arduino UNO Q communicates with a Python program running on the microprocessor side to convert vector files into physical drawings.

The project is documented in full, including Fusion and STEP files, PDF drawings, and source code, on GitHub. Anyone inspired to make their own gadgets with the Arduino UNO Q, meanwhile, are invited to enter our Invent the Future with Arduino UNO Q and App Lab contest for a chance to share in a prize pot totaling $20,000.