NASA RASSOR BUCKET DRUM

Last crawled date: 1 year, 11 months ago

Here's my entry for NASA RASSOR Bucket Drum Design Challenge.

Maximum length = 360mm
Maximum diameter = 440mm
Weight = 4.81Kg
Material = Aluminium 6061
Manufacturing type = SLS additive manufacturing using EOS P760 with 86% fill density.
Total volume = 38.04 litres
Volume captured = 29.04 litres
Fill ratio = 76.34%
Time required to fill the drum = 148.5 seconds.
Number of scoops = 3
Scoop dimension = 60x125mm

Designed in Creo parametric 5.0 and simulated in Altair EDEM, ANSYS Workbench.
Whole design development process can be accessed through the pdf documentation available as a downloadable file.
I started to develop the design by first dividing the problem statement into primary and secondary objectives. I developed three different designs to study the parameters such as Fill ratio and Filling rate. After identifying the parameters I started the development of final design which provides the best compromise between all the parameters. In order to do so i took inspiration from Archimedes screw and python digestion system.
The drum is designed using Creo parametric for 3D printing using aluminium 6061 and 86% fill density.

SIMULATION:

Further in order to verify the results a simulation was carried out in EDEM to measure the fill ratio and time required to achieve that fill ratio.
The drum has a fill ratio of about 76% when operated through a definite cycle which is explained in documentation provided in the downloads.
I don't have a workstation PC so in order to reduce computation time, power and memory I decided to keep the Drum stationary at one point and rotate at 35 rpm and the particles were added to a polygon defined as an inlet with unlimited particles(10000 particles/second) and time step was 1 second, the particles possess the same properties as that of sand and gravity was set to 1.62m/sec^2. These steps really helped me to complete the simulation, after that I derived the important parameters from the simulation so as to see the possible result of the drum had it been rotated at 20rpm.
Through this process I calculated that the maximum amount of regolight captured is 29 litres and 76.34% of the total volume. I have also uploaded the video of extraction of regolith in the downloads, so see how the drum achieves a fill ratio of 76.34% and how its works please refer to the documentation provided in the downloads.
Finally for manufacturing purpose I chose SLS additive manufacturing technology using EOS P760 Machine which has a large bed of size 700 × 380 × 580 mm that can easily accommodate the component.
VIDEO LINK: https://drive.google.com/open?id=1nkAUrkJT0UXI0hnzjcHqWGVjpwYYn656

Included in downloads: Design Documentation, Renderings, Regolith extraction simulation video, Step file, STL file.