This paper details the electrical and mechanical design of a de-spin mechanism for the payload of an all-rotating aerial vehicle. The system is designed to be compatible with the Aeroseed aircraft developed by Aerospace Corporation. The system consists of a motor housing and a de-spun payload plate. The payload plate serves as a mounting surface for the desired de-spun payload, an IMU, an Arduino Nano, and a SD card module. The Arduino receives rotational velocity readings of the payload plate from the IMU and calculates the necessary spin rate to stabilize the rotation. This spin rate is sent through a slip ring to the motor and ESC enclosed within the motor housing, which implement the commands. The electronics on the payload plate are protected by a thin shroud that extends down from the motor housing. A slider mechanism with two degrees of translational freedom serves as the interface between the system and the aircraft and allows for the alignment of their respective centers of rotation. The final design has a total mass of 589.67 g and a height of 109.1 mm.