"Print-in-place" Roller Bearing

grabcad

Design Conception: When developing this design, I aimed to capitalize on the strengths of 3D printing and make the most of its capabilities with my entry. The aspect that resonated with me is the "print-in-place" opportunities that 3D printing offers. Being able to seamlessly construct enclosed geometries in one place (without any traditional manufacturing or processing) is a great way to reduce costs and complexity. Another key idea I pursued was creating a design that can be easily printed on all (entry-level and above) 3D printers with standard 0.2mm layer heights (and 0.4mm nozzle), as I wanted to demonstrate the capabilities of even cheap 3D printers and make my design accessible to the entire 3D printing community. I started by researching different types of bearings. I avoided traditional "ball" bearings, as their spherical components would be difficult to print on a small scale. The idea of a "roller" bearing seemed perfect for this project, allowing for good first-layer contact with the print bed. I chose a 608 bearing as the standardized size for my design because it's very common and widely used. Using CAD software, dimensions can be easily changed to match other bearing sizes. Design choices: After extensive testing, the unique "peanut" shaped rollers proved to be the most effective. Their geometry allows for an easy print by maintaining sufficient cross-sectional area throughout their entire height. They are also less prone to frictional losses due to reduced contact areas with the rings. Additionally, the grooves placed on the outer and inner rings help keep the "peanut" bearings on track and always captive within the enclosure. Real bearings typically have cages to create constant spacing between each roller or ball and prevent bunching. In my design, I adapted this idea by adding small teeth on the outer ring, which keeps each roller in its respective portion. Details: The attached STL file was created with FDM printing technology in mind but can be easily adapted to other methods. The model has been optimized to be quick to print (under 30 minutes). I used stress simulation to determine the force propagation of the bearing in an uneven loading scenario, which helped me evaluate adequate thickness for the rollers and cages. The design depicted in the images features grooves on the outer and inner rings for extra grip, but these details are mostly aesthetic in nature and can be omitted. For this reason, I have also included the STL file for the simplified version. I'm confident that given time, the 3D printing community will come up with far more interesting and clever usages than the ones shown in my video. Tips for printing: - If the bearing does not have full movement after printing, it is likely a bed leveling issue. You can still try gently breaking the rollers free. - BE CAREFUL when removing the bearing from the print bed, use a spatula to slide underneath. - Ensure the print bed is clean, as the first few layers are crucial in the smooth operation of the bearing. - Print the bearing so the side with the surface indents is flat to the bed. Alternatively, these surface indents can be removed entirely (see pictures for examples.) School/University: Monash University (Melbourne)