Paper Airplane Launcher - CVN-65

This is a paper airplane launcher capable of being powered from a Milwaukee tool battery or other 12v source.  It is designed to be safe and robust, in that the components are oversized and the electronics are deliberately chunky.

As built, the top speed is enough to shred paper airplanes… which is awesome.

It's been tested at the Nova Maker Faire, running all day and delighting children of all ages.  The look on their face when it's turned up a bit high and the plane sails across the room is awesome.

Printing and Assembly Notes

The flywheels must be printed in TPU to grip the planes well.  I printed them as mirror images of each other, so that when spinning the curves line up.  I also printed them with 50% infill, to make them heavier - more weight in the wheels gives less slowdown when launching planes.

The spacing between the motors is adjustable by printing the motor spacer.  I had the best operations with the spacers printed .8mm thick, which leaves a very small gap between the wheels when they're still.

 

Parts List

This is the speed controller I used: 
HiLetgo 12V~40V 10A PWM DC Motor Speed Control Switch Controller Voltage Regulator Dimmer for Arduino: Amazon.com: Industrial & Scientific

and the motors: 
775 DC Motor 12V-24V DC Motor High Torque DC Motor 10000-20000 RPM Dual Ball Bearings Quiet Power Wheels Motor Upgrade DC Motor（with Bracket） (2Pack - D Shaft Motors) - Amazon.com

I used these to attach the flywheels to the motor - I was paranoid that they'd break free, and by tightening screws from coupler to wheel you can balance the wheels to some degree:
QCQIANG 5PCS 5mm Flange Coupling, Motor Shaft Coupler, Flanged Shaft Mount, for DIY Handmade Model: Amazon.com: Industrial & Scientific

optional photoresistor relay - didn't work with my external power supply, but worked fine when running off of tool batteries:
D-FLIFE 5pcs XH-M131 Photoresistor Relay Module, DC 12V 10A Light Control Switch Photoresistor Relay Module Detection Sensor Brightness Automatic Control Module with Cable: Amazon.com: Industrial & Scientific

the big ol switch - common wired to ground, then one ON goes straight to the speed controller, the other to the photo relay then to the speed controller
Amazon.com: Joinfworld Waterproof Toggle Switch 12V Marine ON Off ON 3 Pin 3 Position SPDT 12 Volt DC 30A Heavy Duty 3 Way Toggle Switch with Boot Cap Cover for Car Auto Truck Boat - 3 Pack : Automotive

optional Milwaukee 18v battery mount - the speed controller, motor and business side of the relay are cool with 18v but the trigger side wants 12v, so running relay off of a battery you have to add a 12v dc-dc converter.  I used a tiny one I just had lying around, the relay module doesn't use any power, really.
Amazon.com: 2 Packs Power Wheel Adapter for Milwaukee M18 Battery Adapter 18V Power Wheels Battery Converter with Fuses & Wire Terminals, 12AWG Wire, Power Connector for DIY Rc Car Toys, Robotics and Rc Truck : Tools & Home Improvement

You'll need some M3 bolts and hex nuts to attach the flywheels to the coupler, and some M4 bolts to attach the motors to the frame.

 

Wiring

I'll get a picture of the wiring up… but it's pretty simple:
 

1. power supply (either the battery or a 12v wall wart) positive goes to the speed controller and photoresistor relay electronics side (not the relay side)
2. power supply negative goes to the switch and photoresistor relay electronics side (not the relay side)
3. First switch leg goes to the speed controller input side
4. Second switch leg goes to the photoresistor relay common, then from the NO port to the speed controller, same terminal as the first switch leg.
5. The motors are then connected to the speed controller motor outputs - note that one will be wired in backwards, and pay attention to the direction so that it launches planes forwards.
    

Tool batteries can put out a ton of power quickly - if you're unsure about the wiring, I'd use a 12v wall wart to get things spinning correctly and then swap to the battery as desired.