What was accomplished

This week focused on the physical integration interface between the Drop System and the quadcopter. Two structural components were designed: a custom vertical standoff to mount the payload mechanism to the drone's lower deck, and a central integration plate connecting multiple drop systems into one unified multi-payload module.

This work culminated in the master assembly for the complete multi-payload Drop System, marking the official conclusion of the digital design phase. Three independent motorized winch modules were digitally integrated onto the centralized integration plate, and the entire module was virtually mated to the quadcopter's lower carbon fiber deck using the reinforced vertical standoffs. The master CAD assembly verified that all components, sub-assemblies, and structural interfaces fit precisely with zero interference.

Challenges and solutions

The main challenge was ensuring the mounting connection could withstand flight vibrations and the combined weight of multiple payloads, resolved by adding structural ribs (gussets) to the vertical standoffs for rigidity, and using a single integration plate to prevent the individual drop systems from moving or swinging independently.

A further key challenge was managing the drone's dynamic center of gravity — hanging three independent winch mechanisms, each eventually carrying a dense payload, beneath the airframe risks flight instability if weight is unevenly distributed. The integration plate was engineered with a symmetrical 120-degree radial layout, orienting the three drop systems in a triangular geometry so mass is evenly distributed around the drone's central vertical axis. This ensures that even as individual payloads deploy and total weight changes mid-flight, the center-of-gravity shift is minimized and easily compensated for by the flight controller.

Next Steps Plan

With the digital CAD phase fully validated and finalized, the mechanical department will transition from conceptual software design to physical manufacturing. The primary objective is to begin the 3D printing process for all custom components — including the gear housings, spools, and integration plates — translating the finalized digital geometry into physical hardware.