Caliburn Blaster Chronometer

I enjoyed NERF foam blasters as a kid.  As an adult, a friend of mine Spencer Buhler introduced to the adult hobby of making your own blasters.  Many hobbyist groups like the Captain Slug website publish designs that may be 3D printed and assembled with some metallic hardware.  After building my "Caliburn" model (pictured below) I wanted to see how fast it could shoot foam darts.  Rather than purchasing a chronometer, I decided to make my own with a pair of laser trip wires.  I designed the photodiode receiver circuits on prototype board, and collected the sensor input with an Arduino UNO.  According to my chronometer, my Caliburn was shooting at 220 feet per second.  For reference, and off-the-shelf blaster for kids will shoot about 50 feet per second.  The source code is hosted on GitHub here.