Every Chell costume needs a portal gun, and Redditor Pastlightspeed put one together on the cheap. She wanted to carry it during a 5K run, so it was also important that the weapon be lightweight. She put the gun together for less than ten dollars with cardboard. Her pictures on Imgur give you an idea of the process, but here are the basics:
Basic cardboard structure using layers of cardboard and sawed sections of tubing.
It was painted with black and white spray paint.
he detailing is cut-out blue and black construction paper. Logos are printed on normal printer paper, cut out with an x-acto knife, and placed using adhesive spray.
To achieve the colored inner tube, I rolled a piece of blue construction paper and secured it on either end in the inside of a flat, doughnut shaped piece of cardboard. Rolled and secured on the outside of the doughnut is a clear sheet protector (a glow stick would’ve been perfect as the inner tube if the run had been at night).
Read more at Imgur.
via Super Punch