i had a laser housing and an empty ps1 namco gun shell so i made a laser gun it uses 11mm laser housings, just the silver one people usually use i included the sketchup file if you want to edit it you can turn a namco gun into a laser gun without any mods to the case, you just need to empty it out for the trigger button, i took of the reset button from a fried arduino mega, soldered it to a piece of perf board that fit in the holder and connected it to the circuit in series, its obvious once you see the trigger assembly