ULA Bracket Redesign

Redesigned internal boattail support bracket for ULA Rocket Hardware Challenge. The bracket has been separated into two pieces to minimize mass. All bolt holes are surrounded by a cylinder of material that has a diameter of 4x the hole diameter (exceptions occur where the envelope of the original part does not extend that far). The bracket also contains a unique feature where an internal pocket of material is removed to further reduce weight. A feature like this is only possible with additive manufacturing. When oriented properly, there is no support material needed within this internal pocket. I have also uploaded a small display stand that can 3D printed and used to mount your bracket. Feel free to modify it for your own design. Update (2016-10-26): A prototype of the bracket has been successfully 3D printed using a Stratasys Dimension BST 1200es. This bracket was printed in ABS plastic (Ultem 9085 not available) with breakaway support material. The main purpose of the trial was to confirm that the part could be successfully built using the chosen orientation and that the breakaway support could be removed without difficulty and without causing damage; this has been confirmed. Physical and Mechanical Properties Calculations: Total Part Mass = 0.099 pounds Total Part Volume = 2.042 cubic inches Maximum Stress @ 600 lbf Load = 3838 psi (see attached stress plot) 3D Printing Calculations: Total Support Material = 0.62 cubic inches Total Print Time = 4 hours Print material volume and print time were calculated using Stratasys CatalystEX software. See attached image for model orientation during print. Given Information: Material = Ultem 9085 Material Strength Allowable = 4500 psi Specific Gravity = 1.34 Poisson's Ratio = 0.41 Young’s Modulus = 325 ksi