Model Rocket Launch Controller – Dual Circuit, Key-Armed System

This project is a purpose-built model rocket launch controller designed to provide safe, reliable ignition for single or dual rocket launches using commercially available igniters. The controller is powered by an internal 12 V lithium-ion battery protected by a 7.5 A inline fuse, providing ample current for short-duration ignition while maintaining electrical safety.

The system supports one or two simultaneous launches via two independent ignition output circuits, allowing either individual or dual ignition from a single controller. Each ignition circuit is controlled by its own LED-illuminated safety switch, enabling the operator to positively enable or disable each launch channel independently. This provides an additional layer of control and prevents accidental ignition of an unintended circuit. Each circuit has been tested and can deliver 7 amps of current to the igniter.

Each output circuit is also equipped with a dedicated continuity indicator LED, providing immediate visual confirmation that an igniter is properly connected and electrically intact. To further enhance situational awareness during pad setup, the controller includes a switchable continuity alarm. When enabled, an audible buzzer activates only when continuity is present, allowing positive confirmation of igniter connection without relying solely on visual indicators—particularly useful in bright outdoor conditions or when operating at a distance.

Launch activation is performed using a large red momentary mushroom-style push button, providing a clear, deliberate, and tactile firing control. The launch circuit is further safeguarded by a key-operated arming switch, ensuring the system remains electrically safe during setup, transport, and recovery. The controller cannot initiate a launch unless the system is intentionally armed and the selected ignition circuit(s) are enabled.

Additional features include an integrated battery voltage meter for real-time monitoring of battery state, a dedicated battery charging port for convenient recharging without battery removal, and internal cord storage with an integrated cord spool to manage launch leads cleanly and reduce setup time.

This launch controller is designed with a strong emphasis on electrical safety, positive user feedback, and field practicality, making it well suited for hobbyists, educational environments, and organized model rocketry operations.
 

Enclosure and Materials

The controller enclosure is fully 3D printed in ABS to provide improved durability, impact resistance, and UV resistance for repeated outdoor use. A printed TPU gasket is integrated into the enclosure design to help protect internal electronics from dust and incidental moisture intrusion. Enclosure hinges use (6) M4x45mm screws.

The faceplate is secured using a removable retention ring, allowing the front panel to be firmly captured during operation while still permitting non-destructive disassembly for inspection, repair, or future upgrades. This approach maintains enclosure integrity without permanently sealing the unit. Faceplate is secured using (8) M3x6mm screws.

Internal mounting brackets, component holders, and structural features are 3D printed in PLA, balancing strength, dimensional accuracy, and ease of fabrication for non-exposed internal parts.

Additional Parts

Additional parts are available from the amazon list here:
[https://www.amazon.com/hz/wishlist/ls/2CZYMSUGWI4JG?ref_=wl_share](https://www.amazon.com/hz/wishlist/ls/2CZYMSUGWI4JG?ref_=wl_share)