As I outgrew the restraints of my original 3D printer I bought in 8th grade, I decided to upgrade rather than buy new machines, as dual material 3D printers had not been developed that were cheap enough for me to use and worked reliably. I completely overhauled the mechanics, wiring, and firmware of the machine.
Almost all consumer grade 3D printers at the time were limited to a single nozzle with one filament. This was an issue for me, as I had recently started designing and printing my 3D topographical maps, which needed at least two colors to be usable. To achieve this goal, I began the process of designing and 3D printing upgrade parts and overhauling the cicuitry of my printer.
My first goal was to maintain the highest percentage of original parts while allowing for dual color printing. I did this by adding a filament path splitter, allowing two seperate filaments to be used in one nozzle. This method worked as intended, but had the major downsides of waste filament and extended print times. This was due to the swapping of filament that had to occur, as well as the purging of filament to ensure the nozzle was primed. These issues led me directly to implement the next upgrade.
The next upgrade incremented on version 1 by replacing the y-splitter with true dual nozzles and heaters. This improved the printing speed, as much less time and material was needed to swap between filaments. This also allowed for true multi-material printing, as different materials such as PLA and TPU or ABS could be printed simultaneously.
Issues with version 2 included oozing of the nozzle that was not being actively used, as well as incredibly hard and often servicing to the hotend. To correct these issues, I designed my own hotend from the ground up to be hot-swappable, easily modified, and use more reliable parts. I designed this system to use two completely seperate hotends mounted to the same motion system. This decouples each hotend from the other, allowing for replacement or repair of one without modifying the other. This system also includes a mounting plate that can be removed for service with a single screw.
Throughout this process, I have learned a great amount modifying existing technology and about designing systems for daily use. In the first versions of the printer, I focused most of my effort on a functional product. During this phase, I learned how to code the firmware, wire the printer, and reinstall almost every printer component. However, I quickly realized that a functional system has to be accessible for improvement and for service. This was the cornerstone of version 3, so that I will have a much easier time maintaining and upgrading the printer in the future.