The Manhattan Project PDR Notes

Owned by Donovan Barros (RIT Student)
Nov 02, 2024
3 min read

  • Structures

    • The motor should have a fast burning motor (low burn time)

    • Look into shorter burn motors

    • Make sure stability is calculated by graphing for off-the-rod stability in different wind conditions (follow the design document)

    • Try to minimize empty space

    • Figure out how the avionics bay is secured

    • Don’t lock yourself into a fin design, they can be done at the end

    • Fin Flutter calculations are incorrect

    • Missing bulkheads

    • Missing thrust plate

    • Missing nosecone

    • Missing motor retainer

    • Missing access points

    • Consider access points

  • Payload

    • Add in payload mission requirements

    • PETG is not 1.5 cents per gram anywhere for good quality

    • All designs would need CAD

    • Carbon Fiber would restrict antenna design and location

    • Look into more material options for capsule (Delrin, reinforced cardboard)

    • Specifically, call out complexity and/or failure points in new designs instead of simply listing new designs as a con

    • Rails could catch recovery hardware

    • A tight spring could be an energetic

    • Use a solenoid or something similar instead of a servo

    • Characterize the drag on the propellers

    • Weight concerns for such a small recovery system

    • Look at NASA paper Alan found to calculate rotor diameter

    • Consider different drags for spinning the whole payload vs just spinning the payload

    • Consider frictional effects when not spinning the whole payload

    • Re-evaluate design criteria so each doesn’t have the same pros and cons

    • Be careful about balancing the payload mass

    • Consider using a thrust bearing instead of a ball bearing

    • Do more research into different types of hinges

    • Consider SRAD pin and hinge options

    • If 3D printing rotors, add in external reinforcement on top of print

    • 3D printing rotors may also be challenging due to post-processing

    • Look into resin printing for the rotors

    • Why four rotor blades?

    • Start prototyping rotor blades now

    • Look into Alan’s other NASA paper on whirlygig designs

    • Look into different whirlygig manufacturing options

    • New Barbie option: Lexi’s

    • No Ebay

    • Safety concerns picking up barbies

    • Use separate batteries for tracker and radio beacon

    • Make sure cell service is available for watch tracking

    • Test durability of watch tracking

    • Test watch in L1

    • Make sure watch can survive impact

    • LOTS OF TESTING FOR WATCH

    • Foxhunt practice

    • Beacon is unreliable on the unlicensed band

    • Get HAM licenses

    • Look into the IREC foxhunting beacons

    • Make something then give structures that mass, don’t worry about conforming to structures before the design is finished

    • Minimize angular moment of inertia

    • Flexible barbies

      • Willing to cut barbie in half

  • Avionics

    • Great job on the requirements slides

    • Higher-res graphics

    • Passed the screw switch quiz

    • Name charge lines/signals primary and secondary

    • Look over quarks or other flight computers carefully if not assembling yourself

    • Could use different flight computers if need be

    • Delpoy main failsafe is better than ballistic

    • Look into RRC2L (we have 4)

    • Heat shrink GPS onto the eggtimer TX

    • Consider radiosondes as a tracking option

      • Radiosondes are big

    • Make sure batteries can give enough current for charges

    • Look at more batteries

      • Expand search outside of apogee components

      • Look at other battery chemistry besides LiPo (Lion or others)

  • Recovery

    • Jolly Logic is a good option for this application, proven success in HPR

    • Making jolly logic dual redundant is a challenge

    • Strength test to make sure the logic can survive opening snatch

    • RIT Launch has minimal experience with dual-bay rockets

    • Have experience with the success of tender descender single-bay rockets

    • Careful about load paths

    • Dual bay requires double the amount of charges

    • Consider how much wiring is needed to run to the charges

    • Single Bay vs Dual Bay decision is the most important blocker for the team as a whole

    • Use base values to start design, don’t push it all off

    • Use previous PDR and CDR for SR to generate starting values