dual rotating axis 3D printer design

thingiverse

I'm new to 3D printing and I'm extremely impressed with the community here at Thingiverse. I want to give back to this amazing group, so I've come up with a unique design for an alternative 3D printer. As an engineer, I tried to imagine a fresh approach to 3D printing, and this design is the result. This basic design for a mostly printable 3D printer consists of two main rotating bodies: one that serves as the "dish" print surface (A) and another that acts as the "arm" (B). The arm holds the "hand" (C), which can move up or down along the Z axis. The interlocking rotation of these two bodies provides the necessary degrees of freedom for the X and Y components. The strengths of this design are numerous: 1. It's easy to assemble and extremely robust. 2. Almost every part can be 3D printed, making it a highly convenient option. 3. Multiple arms can be added (up to four in total) and combined with additional dishes and heads to enable simultaneous building of up to four identical prints. 4. This design should produce less noise compared to traditional printers, as it primarily relies on rotation rather than sliding motion (only the Z axis slides). 5. It's ideal for creating round objects. 6. You can even give your printer a unique R2D2-like appearance! However, there are some potential pitfalls to consider: 1. The X/Y resolution is variable, with lower resolution at the outer perimeter and higher resolution in the center. 2. Achieving high speeds near the center of the print surface may be challenging (special code could help resolve this issue). **Construction** The dish is actuated by a pancake stepper that makes it rotate, keeping the height low and improving stability. A 200mm "Lazy Susan" bearing would work well for this purpose, along with a timing belt attached to the outside of the bearing (with teeth facing outward) that contacts the stepper directly. Alternatively, a tensioned timing belt or nylon gear could also be used. The arm can have a smaller diameter but should be as wide as possible to ensure stability. It can hold a NEMA 17 stepper (or even a NEMA 23 for better performance). The "hand" should sit on a 300mm linear slide bearing, such as the HIWIN 12 model, which can be actuated by a NEMA 17 size stepper with a lead screw. To prevent filament movement and associated issues, it's best to connect the supporting surface to the base via a shaft. This would keep the filament from unwinding or adding extra load/inertia. Unlike the arm and hand, the dish does not require end stops and can rotate infinitely. It could have a heater connected via brushed contacts, while its temperature sensor would be stationary with a small bearing fitted over it (touching the bottom part of the plate). This setup provides conductive heat transfer to the sensor without needing additional brushed terminals. There are some equations that provide the A and B angles from X and Y coordinates, considering radius r1 "dish" and r2 "arm". However, these should be easy for a mathematician to understand. I'm a bit rusty on my math skills, so any volunteers would be welcome! This printer would work more efficiently if code was optimized to take advantage of the circular motion. For example, filling would best be done in a circular motion using a circular pattern. You're welcome to improve this design and actually create the printer parts. I have limited time available at the moment, but I'd love to discuss and provide suggestions. Is there anyone out there brave enough to take on this exciting project?