ENGS 89/90 Reports

Year of Graduation

2025

Project Advisor

Elizabeth Murnane

Instructor

Solomon Diamond

Document Type

Report

Publication Date

2025

Abstract

With recent technological advances, 3D printing has become widely accessible. This has allowed for greater ease in producing and obtaining machine gun conversion devices (MCDs). MCDs have the capacity to turn semi-automatic rifles and handguns into fully automatic machine guns. Even though it is illegal to print, own, or sell MCDs, print files for these devices are freely available on file sharing websites and easy to produce via 3D printing. It naturally follows that this increase in access to MCDs increases the potential risk for mass shootings. Additionally, 3D printing technologies are becoming increasingly prevalent in educational settings, such as makerspaces. This further increases students' access to MCDs. This project thus seeks to produce a safer, more usable 3D printer that both prevents the printing of MCDs and is more appealing for use in educational settings. There are three main components of this project that will be developed simultaneously. First, for the software end, current market software companies (such as Materialise) are working on MCD detection. To this end, they are developing a slicing software that is able to detect potential MCDs in 3D print files based on key object geometries. The slicing software then outputs a G-code file along with a binary flag indicating whether or not an MCD was detected by the slicing software. This project will extend upon the MCD detection output by developing a software routine which will be embedded in the slicing software. This software routine will secure the G-Code and ensure that the G-Code produced by the slicing software with MCD detection capabilities is the same G-Code that is provided to the 3D printer. This will be accomplished by computing an encrypted signature only on G-Code files for prints in which an MCD was not detected. This project will also thus need to modify an existing 3D printer's firmware such that verification of the encrypted signature becomes possible. The firmware will need to ensure that the G-Code is signed and that neither the signature nor G-Code have been modified since they were produced by the slicing software. Only if the G-Code file is signed and both the signature and G-Code are found to be unaltered will the print proceed. Second, the hardware component involves constructing a 3D printer from an open-source kit and designing a cost-effective (compared to current market solutions) enclosure using particle board, MDF, and polycarbonate panels. The enclosure will feature an integrated ventilation and carbon filter system for heat and VOC management, along with a secure locking mechanism to enhance safety. Our MCD detection software will be integrated into the printer’s firmware. Our MCD detection software will then be integrated into the firmware of our constructed printer. Finally, the UI/UX component is centered around a user-focused approach to create an intuitive and effective training experience for young 3D printer users. Our work is divided into two main segments: user research and user testing. Initial research has identified slicing software as a key pain point, driving our goal to design a new, simplified interface tailored for educational use. In the second phase, we will conduct usability testing with local elementary and middle school students, utilizing tools like Maze and Amplitude to gather both qualitative and quantitative data.

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