The Pen Printer

This project placed 2nd in the 2022 3D Experience Project of the Year Competition, thanks for all the support everyone! Check it out here: https://poty.edu.3ds.com/ The Pen Printer was our Engineering Honors final project at Francis Parker School, and as a pair of high school sophomores, we spent approximately 9 weeks on the design, programming, and refinement of the machine. The project's goal was to create a CNC-style printer with the ability to process and output both dot and line art in just a few hours. Consequently, the final design has three degrees of freedom, with the ability to move in the X, Y, and Z plane. Utilizing stepper motors with accuracy of up to 0.1125 of a degree in the X and Y axes, the printer can achieve an astounding resolution of 3840 x 2160, barring physical limitations from the width of a pen. In actuality, this yields resolutions of 635 x 476 when utilizing a 0.4 millimeter pen tip, still enabling the creation of high quality images. The stepper motors — with GT2 timing belt wrapped around a pulley — ensures rapid movements, which would otherwise be lost with a leadscrew mechanism, whilst still maintaining the desired precision of a CNC machine. The entire assembly was designed in SOLIDWORKS, and includes a widespread variety of manufacturing techniques: CNC machining, manual machining, additive manufacturing via 3D printing, and laser cutting. The Z-axis of the CNC utilizes a rack and pinion mechanism, which we designed from scratch in SOLIDWORKS through the use of equation driven curves. To analyze the model and ensure its rigidity, a stress analysis was conducted using SOLIDWORKS Simulation software, thus ensuring that the mechanism would not fail under cantilevered load. Following the construction of the assembly, we used Python to develop an image processing program that would construct a list of instructions from a camera input. Utilizing the OpenCV library, the computer uses a Gaussian threshold image processing algorithm to conve