Super Galaxy

grabcad

DEAR EVERYONE, I'd like to walk you through the thought process behind designing the "Super Galaxy" bucket drum seen above. This explanation and accompanying files are my contribution to the NASA Regolith Advanced Surface Systems Operations Robot (RASSOR) Bucket Drum Design Challenge. 1 - BUILDING UPON RASSOR 2.0 Given the time spent developing bucket drums for Rassor 2.0, I felt it was essential to build upon their acquired knowledge. This approach would save them time modifying or rebuilding their existing prototype and allow them to leverage their learnings while expanding on new designs. After reviewing the team's reports and comments on the original Rassor 2.0 design, I decided to retain its external shape (two semi-ellipses), configuration (four sections in one bucket with a 45-degree angle between them), and teeth. The latter have been described as efficient grippers once they make contact with regolith. From there, I focused on designing the interior while minimizing complexity and mass. 2 - LIST OF PARTS AND RENDERINGS Here's a breakdown of the parts used in my design: * Scoop: A curved sheet of carbon fiber/resin, 2mm thick * Baffle: A curved sheet of carbon fiber/resin, 2mm thick * Stand-Off: A curved sheet of carbon fiber/resin, 1mm thick (or a 3D printed titanium part depending on location) * ZAG: Set of four parts: + Two V-shaped folded laser-cut sheets of aluminum (or 3D printed out of titanium), 1mm thick + Two U-shaped folded laser-cut sheets of aluminum (or 3D printed out of titanium), 1mm thick * Plate: A laser-cut sheet of aluminum, 2mm thick * Plate_End: A laser-cut sheet of aluminum, 2mm thick Note that some parts are not shown in the renderings, including rivets to hold certain components and flanges on the carbon parts. 3 - ASSEMBLY The carbon parts (scoop and baffle) are slid into the plates as in Rassor 2.0. The V-shaped holds can be mounted directly to the carbon parts before they're attached to the panels, while the U-shaped holds are mounted onto the panels prior to sliding the carbon parts. 4 - PRINCIPLE The regolith enters through the scoop and exits from the window opening. Rotating in one direction, the bucket drum scoops the regolith, which is then immediately redirected and passes through a Tesla Valve-like mechanism (ZAG). The ZAG prevents regolith from escaping, allowing it to fill the internal volume. As the drum rotates in the other direction, the former entry point cannot be reached due to the ZAG region, and the exit channel scoops regolith from the internal volume. It's essential to add teeth at this location for efficient scooping. The design allows for comfortable filling of the bucket drum. When going through the ZAG, if the regolith takes too long to escape, the ZAG itself can hold the remaining regolith until the following revolution. REQUIREMENTS * Maximum total width of scoops engaged at any given time: 80 mm * Maximum bucket drum mass: approximately 3.1 kg (3.5 max with missing elements not shown in renderings) * Maximum bucket drum diameter: 450 mm * Maximum bucket drum length: 330 mm * A minimum volume of regolith captured: approximately 25 liters, filled at 70-75%