Vulcan

This project began by analyzing the shortcomings of my previous Prusa Titan build and exploring improvements made possible by advancements in 3D printing technology. One of the main issues with the Titan was the 18 x 18-inch heated bed, which was heavy and caused significant print quality issues due to the back-and-forth movement of the heavy bed. This also limited print speeds. Additionally, newer 3D printer designs introduced a more efficient motion system, where the bed moved vertically while the gantry controlled the print head movement. Inspired by these innovations, I developed a new lab printer that integrated the latest technology and addressed past design flaws, but that printer was outside the budget I wished to achieve for a personal printer. This led to me thinking of utilizing parts from the old printer along with using 3D printed parts instead of custom machined aluminum parts. 

This time, I prioritized thorough design and planning to avoid the mistakes made in my previous large printer build. I first completed a detailed CAD model, which allowed me to simulate movement, check clearances, and refine the design before committing to any hardware. The CAD model also helped guide my bill of materials (BOM), ensuring all selected components would be within the budget that I had set for this printer. Through multiple iterations, I fine-tuned part movements and optimized interactions based on research and performance data of printers that others had built.

The most challenging aspect was designing the X and Y axes to maintain a lightweight structure for high-speed movement. My initial design used a single stepper motor for the Y-axis and another motor mounted on the gantry for the X-axis. However, I soon realized that a single Y-axis motor could cause misalignment and excessive stress at high speeds due to the connection to a single side of the gantry. Instead of abandoning the single-motor concept, I connected both linear rails moving the y axis of the gantry using belts, ensuring synchronized movement on both sides.

Another major improvement before moving forward with construction was reducing the weight of the gantry that moves the print head along the X-axis. To achieve this, I designed a system where the motor remained on the main frame while the print head was moved via a pulley and belt system. This approach significantly reduced the print head's weight, allowing for higher acceleration and faster print speeds.

To reduce costs, the goal was to incorporate more AM (Additive Manufacturing) components into the design versus that of the lab printer that utilized machined pieces to ensure accuracy. This approach significantly lowered expenses, bringing material costs down to approximately $40 in 3D printing filament, compared to thousands of dollars for custom-machined parts. To achieve this, I leveraged my experience from designing large-scale humanoid robots using 3D-printed plastics, ensuring that each part could withstand the necessary stresses and functional demands of the printer.

Extruder Block Design

The extruder block was specifically designed for AM production to optimize weight, complexity, and integration. 

It needed to support:

• Two print heads,

• A BLTouch sensor,

• Two Bowden tube connections,

• Two bearings for smooth movement along the gantry.

Thanks to the design freedom offered by AM, the extruder block was developed with internal channels and multiple mounting points to efficiently route cables and Bowden tubes while maintaining a compact and functional structure.

Corner Brackets and Structural Components

Another critical AM component was the corner brackets, which played a key role in supporting the rotating X and Y-axis rods while maintaining precise alignment and belt tension. 

These brackets were designed with:

• Integrated bearing mounts for smooth motor-driven motion,

• Single-piece construction to house both X and Y linear rods,

• Thicker sections and denser cubic infill to enhance strength and durability.

The strength and material optimization of these brackets were directly influenced by my robotics research, where I developed techniques to reinforce 3D-printed structures for high-stress applications. These enhancements ensured that the printer maintained rigid structural integrity while benefiting from the cost-effectiveness and adaptability of AM.

The mechanical assembly proceeded smoothly, largely due to the detailed CAD model, which allowed for extensive pre-testing of component fit and alignment. The extruded aluminum was precut to the correct dimensions, simplifying the process to just assembling and fastening the components together.

One of the more challenging aspects was assembling the bed and vertical movement system, as it required fine-tuning to prevent binding in the two ball screws responsible for vertical motion. Through some trial and error with a tape measure and level, I was able to ensure smooth movement and proper alignment.

The combination of extruded aluminum and AM parts greatly accelerated the assembly process, providing both rigidity and adaptability. The full mechanical assembly of the printer, including installing belts, motors, and precision rods for linear motion, was completed in approximately two days.

The electrical assembly progressed alongside the mechanical assembly, particularly in the installation of the motors. 

The printer was designed to use:

• Two NEMA 23 motors for the Z-axis,

• One NEMA 23 motor each for the X and Y axes,

• Two high-torque NEMA 17 motors for the dual Bowden extruder setup.

The system was controlled by a BigTreeTech controller, with plans to integrate a 7-inch touchscreen, though the screen had yet to be sourced.

Electronics Housing and Design Considerations

Initially, I intended to house all electronics in a cooled enclosure beneath the table. However, I reconsidered this design due to the challenges it would pose for maintenance and mobility. Instead, I opted to mount all electronic components directly to the bottom of the printer, using ¼-inch acrylic as the mounting surface.

Progress slowed as I worked through the best methods for cable management and component accessibility. 

The goal was to ensure that:

• Cables were routed efficiently,

• Key components were easily detachable for maintenance or replacement,

• Built-in thermal and current protection safeguards were in place.

At this stage, the printer remained in electrical development until the project was eventually discontinued.

Designing and building this printer was an exciting and rewarding experience. However, as my PhD research took priority, the project was gradually set aside. Ultimately, I decided to continue using my Ender 3 and CR-10 printers, as they provided a more ready-to-use solution for my needs. Given my limited time, I chose to focus on other projects, particularly in robotics, where I am able to test more ideas at a faster pace.