Down Selection of Final Design

-Needed to be sleeker and lighter

-3D print had to come out with supports for better results

-Previous failures, as can be seen in the photo, gave better clarity on what was reasonably achievable

-Greater diligence was needed for the primary objective criteria

Final Finite Element Analysis

-9 gram model, satisfies weight criteria

-maximum of 38 microns of displacement

-Under the 100 microns of allowable deflection

-Improved motor strut support now inline with outer frame support for greater structural integrity

Fabrication of Final Design

Wiring schematic

Soldering

Propeller rotation direction

Adhesives

Fine tuning controller

Probability of damage, Printed backup

Replaced motor that had extremely high resistance, indicating no current flow at full throttle. Current is inversely proportional to resistance

Final Result

Lessons Learned

-Many prototypes had to be constructed in order to gain a practical knowledge

-3D printing has advantages but behaves very different from plastic injection molds. Can be difficult and fragile in tight tolerances of high load bearing implications.

-FEA gives a good perspective of which attributes have the greatest influence on the rigidity of a structure. Could have made a lighter drone, but opted to make it stronger for a decent crash.

-Thrust from the powerplant was greatly increased by the structural design

Results

We were pretty happy with our design.

Our design was able to carry a parload of 11 grams in the real test process.
Whereas, in our own test flight, it was capable of carrying a payload of 13 grams.

Conclusions

-Iterative process of design, fabricate, analysis, test and repeat until goals were met

-Subtle improvements made huge differences

-Gained perspective of creating a manufactured performance part

-Teamwork is a vital tool in achieving a conglomerate objective

-Drones are awesome!