RASSOR Bucket Drum V3

grabcad

My design draws inspiration from the current RASSOR V2 drums. I retained the most effective elements of the existing design while implementing upgrades to address the fundamental flaws of V2. FLAW #1: The present design is faulty (like all drum designs with multiple openings), in that any internal geometry intended to prevent regolith fall out from several openings will either; 1) be ineffective, 2) prevent unloading of regolith, 3) lead to soil compaction inside the drum or 4) remove valuable internal drum space. SOLUTION: A drum design featuring only one opening per drum and minimal or simple internal geometry. FLAW #2: With limited internal baffles, regolith grain falls from openings and prevents the drum filling more than 40%. SOLUTION:A simple ramp extending beyond 180 degrees from the opening of the scoop should be sufficient to ensure that regardless of drum orientation, soil and regolith will not unintentionally fall out of the drum. At 55mm wide and 50mm tall, the ramp opening maintains a constant size throughout the design, allowing large and small grains of regolith to pass through to the internal chamber, and helps to avoid soil compaction in both the digging and unloading phases of the operation. FLAW #3:Reducing the number of scoops and cutting surfaces can negatively impact digging speed, thereby increasing the operating time per lunar/martian day to achieve regolith mining volume targets. SOLUTION #3:By narrowing the drums to an internal width of 55mm, two more drums fit within the available 360mm space, for a total actual width (length) of 344mm and 6 drums. This maintains 6 of the previously 8 cutting surfaces, and the increased carrying capacity per drum will more than compensate for any reduction in cutting speed. Any remaining width on the outsides is available for additional attachment hardware, or alternatively the drum widths can be increased to 57mm each. NOTES: The side wall geometry was specifically engineered to ensure that the ramps on both sides of the wall could be entirely secured to the thicker structural support metal, and that all remaining space could be constructed of a thinner and/or lighter material to reduce weight. The intended fill ratio is 80% of theoretical total capacity. Using the inner ramps diameter of 377mm, each drum has an internal volume of approximately 7.62 liters (138544mm2 area x 55mm depth = 7,619,920mm3). Total theoretical capacity of 6 drums = 45.71 liters Intended 80% fill ratio = 36.571 liters SPECS:Width of scoops engaged at any given time: 55mm Bucket drum mass: *4.883kg* Bucket drum diameter: 450mm Bucket drum length: 344mm A minimum volume of regolith captured: (@ 50% fill ratio) = 22.857 liters Due to limitations in Fusion 360, a Carbon Fibre material is unavailable, so a Magnesium alloy was used in its place (with an overlayed Carbon Fibre appearance). The final weight of my design was arrived at using Aluminum side walls, Titanium cutting edges and Magnesium Alloy ramps.