What was accomplished

The mechanical department began the conceptual design and brainstorming phase for the drone's autonomous Drop System. Since payload delivery accuracy and payload survivability are critical metrics for the competition, this phase focused on exploring deployment mechanisms before committing to CAD. Three primary concepts were brainstormed:

1. Unpowered parachute drop: Releasing the payload in free-fall and relying on an autonomously deployed parachute for a soft landing.

2. Bomb-bay trapdoor: A fully enclosed payload pod with servo-actuated bottom doors for a rapid, untethered free-fall release.

3. Motorized winch and tether system: A controlled descent mechanism using dedicated servo motors and spools to slowly lower the payload to the ground via a rope or tether.

To evaluate these concepts, the team went beyond theoretical brainstorming and conducted practical physical testing, starting with a rapid prototype of the unpowered parachute drop system.

Challenges and solutions

4. The primary challenge during this phase was evaluating the delivery accuracy and payload survivability of each concept.

5. The physical drop test of the parachute concept (documented in the attached video) revealed fatal flaws: the payload suffered from unpredictable wind drift, making pinpoint target delivery impossible, and the parachute failed to adequately reduce the impact velocity, causing a hard landing. Similarly, the bomb-bay trapdoor concept was evaluated and quickly discarded, as an untethered free-fall poses a severe, unacceptable risk of completely destroying the payload upon impact.

6. Consequently, the team officially selected the motorized winch and tether system as the final approach. This mechanism is the optimal solution as it guarantees a soft, controlled touchdown and eliminates wind drift, perfectly satisfying the safety and accuracy requirements for the payload.

Next Steps Plan

With the motorized winch concept approved, the team will move into the detailed design phase, beginning step-by-step CAD modeling of the mechanism from scratch — starting with drafting the central baseplate and designing the initial geometry for the motorized spools.