What do you get when you cross a self-taught maker with an enthusiasm for all things Nerf? A mobile nerf gun platform capable of 15 darts per second. Obviously.
The M1 NerfBot built by [GrimSkippy] — posting in the ‘Let’s Make Robots’ community — is meant to be a 
constantly updating prototype as he progresses in his education. That being the case, the progress is evident; featuring two cameras — a webcam on the turret’s barrel, and another facing forward on the chassis, a trio of ultrasonic sensors, controlled by an Xbox 360 controller, and streaming video to a webpage hosted on the M1 itself, this is no mere beginner project.
Perhaps most compelling is how the M1 tracks its targets. The cameras send their feeds to the aforementioned webpage and — with a little reorganization — [GrimSkippy] accesses the the streams on an FPV headset-mounted smartphone. As he looks about, gyroscopic data from the phone is sent back to the M1, translating head movement into both turret and chassis cam movement. Check it out!
The firing assembly in the jet comes from a Nerf Rival Zeus Blaster, which is itself an interesting device. It uses two electric flywheels to launch soft foam balls – much like a pitching machine. With one flywheel running a little faster than the other, the trajectory can be modified. For example, a slight topspin gives the balls a longer and more stable flight path. Of course, foam balls slow down quickly once launched and at high speeds the aircraft can overtake the same projectiles it just fired, but it’s fun all the same.
First, he prototyped a single beam-break detector (shown above) and then expanded his build to two in order to get velocity info. A Propeller microcontroller took care of measuring the timing. Then came the gratuitous statistics. He took six different darts and shot them each 21 times, recording the timings. Dart #3 was the winner, but they all had similar average speeds. You’re not going to win the office NERF war by cherry-picking darts.
