The design for our missile battery starts with the frame mounted to the skids of the helicopter. Originally the frame was designed on Autodesk Inventor and was to be printed with ABS plastic and mounted straight to the skids. However, despite having a working 3D printer at our school last year, nobody at our school can figure out how to get the 3D Printer setup again.
The original design for the missile battery was to look like this:
The design also included disposable fins and nose cones that could be mounted to the body of the rocket:
I decided to start a new design made of balsa wood for the missile battery frame. I cut all of the balsa pieces and proceeded to shrink wrap the wood in plastic for both aesthetics and durability. Army was able to get some carbon fiber tubing for the missile tubes which was cut and epoxied to the frame. You can see the pictures of the completed frame below.
The entire control system for the signal lights and the radio equipment is all wired to an Arduino Nano microcontroller. The microcontroller is powered by a 9 volt battery that sits on the missile frame. The microcontroller is programmed to flash the lights and wait for a signal that is received by the radio receiver unit that is located in the front of the helicopter. This radio is from a mini Uniden Walkie Talkie and it outputs an analog signal to the microcontroller whenever the paired unit’s talk button is held down. After the paired walkie talkie is triggered for 3 seconds, the microcontroller applies 5 volts to a relay which then passes 9 volts to the rocket fuses.
These are some pictures of the completed setup for our Walkera Lama 3 Missile Battery. The missile tubes are carbon fiber and the battery frame is made of balsa wrapped with heatshrink tubing.