When I first witnessed the emergence of 3D printing technology, I was captivated and knew I wanted to have a printer of my own. However, I had a vision that went beyond purchasing a pre-built machine; I wanted to create my own 3D printer from scratch. Thus, I embarked on a research journey, exploring different printer types around 2014, their components, and just how they worked mechanically and electrically. During my investigation, RepRap became my go-to source, offering invaluable insights into printer builds and assistance from other makers. Among the various options, the Prusa clones stood out for their simplicity and straightforward assembly.
Originally, I considered building a small i3 clone as my first printer, but my ambition grew. I wanted something much larger and capable of greater prints, motly I found files for 3D printed storm trooper helmets and wanted to print one of those. Scrolling through Instructables, I stumbled upon the plans for an i3 clone with eight times the standard build area of other printers that were currently being made by makers. This design enticed me, particularly because it required minimal reliance on 3D-printed components since at the time I did not have easy access to a 3D printer. Fortunately, my university, Virginia Tech, offered free 3D printing services for students, which provided a convenient solution for obtaining the necessary printed parts.
Link to Printer: https://www.instructables.com/Mega-Prusa-i3-Rework-8-x-Build-Volume/
Determined to create a cost-effective large printer, I conducted thorough research and compiled a comprehensive Bill of Materials (BoM). This involved investigating various designs and sourcing parts from different suppliers to ensure affordability. I set a budget of $1,000 for the project. Being an engineer, I couldn't resist the urge to add my own modifications and improvements, even though I had limited knowledge of 3D printing and component integration at the time. This last bit would test my patients at times since I had added much more work to my very first 3D printer.
I began by acquiring the 3D-printed parts and hardware needed for the full project since shipping in bulk brought the price down per component. Utilizing readily available threaded rods and nuts from a local hardware store, I swiftly built the base of the printer since shipping was the process of me going to the store. The resulting base, weighing approximately 25 lbs, provided a solid foundation, with parts fitting together perfectly allowing for smooth movement of the print bed. Witnessing the components seamlessly come together to form a functional and movable bed filled me with excitement and a sense of accomplishment with a desire to continue on to build the rest of the printer.
During the construction of the Z-axis frame, I made an early deviation from the original design. Instead of using an acrylic frame with mounted linear rods, which I deemed too flimsy for a printer of this size, I opted for sturdy angle aluminum. This decision presented challenges due to the thickness of the aluminum (¼ inch) and my limited access to appropriate cutting tools. Despite the obstacles, I persisted, and the resulting aluminum frame not only provided robustness but also enhanced stability, enabling future add-ons and accommodating taller prints.
Obtaining a suitable laser-cut acrylic part proved to be a significant hurdle, and I explored various avenues before finding a solution. I contemplated cutting it by hand, but a fortunate turn of events led me to a laser cutter available in one of the labs I frequented. Witnessing the laser cutter precisely cutting the acrylic within minutes was awesome, sparing me from hours of manual cutting. With the acrylic piece in hand, I completed the assembly of the bed, marking a significant milestone in the project.
Considering the printer's large size, I recognized the importance of both mobility and stability. To address this, I designed a table with wheels, allowing easy movement during maintenance and locking it in place during operation. The table's structure facilitated secure bolting of the printer, creating a solid foundation, while concealing all the circuitry underneath in a cooling drawer. Additionally, I incorporated leveling and locking features into the table, ensuring maneuverability and stability, ultimately enhancing accessibility and ease of use.
To address the unique demands of a printer of this size, I implemented several upgrades. First, I opted for NEMA 23 motors on the Y and Z axes, providing the necessary strength to handle the weight and movements of the large bed and the long span between the upward towers.
Another issue that the design had was it used 3 mm threaded rods on the Z axis. This seemed unsteady and slow compared to those that utilized a lead screw. This was one of the first upgrades I completed after the initial build due to the recognizable issues that were mentioned above.
Additionally, I incorporated a Bowden tube system, relocating the motor from the X-axis to the frame. This modification aimed to reduce the weight on the X-axis, potentially enabling faster printing speeds.
Moreover, as a structural improvement, I added slanted bars from the gantry's top to counteract any wobbling observed during test runs, further improving stability. The final improvement was a beautification step with the cable management, I utilized cable seething, ensuring a clean appearance with all electronics neatly hidden beneath the table, converging at a centralized point.
Upon completion, I realized that this printer's design had inherent limitations. Due to the bed's substantial weight and the potential for lots of material sitting on the bed during large prints, I encountered challenges in achieving the desired print speeds. The single NEMA 23 motor initially chosen to drive the bed proved insufficient for efficient operation whether once the bed was moving or slowing down as the weight due to the part size increased causing sluggish movements and slippage. Consequently, I decided to discontinue further work on this printer and salvage its parts for a new design, with the aspiration of achieving significantly faster print speeds.
In conclusion, the journey of constructing a large 3D printer from scratch was an exciting and educational experience. It allowed me to delve into the intricacies of printer design, customization, and overcoming challenges related to size and performance. Although this particular printer did not meet my desired print speeds and required discontinuation, the lessons learned and knowledge gained served as a foundation for my future endeavors, including the creation of Vulcan—a new design aimed at achieving significantly faster print speeds.