The real-deal “Laserex” version is very rare in airsoft circles. Too pricy and requires you to crack your precious P90 body in half for installation. Not so with this homemade version which yielded excellent results for a fraction of the cost. Installation is straight forward if you have some experience building models and can solder a couple of wires together.
The laser itself came from a small dollar store toy pistol. It's pretty cute but it is one import toy not really suitable for little kids. The pistol had no orange tip, and the laser is incredibly bright, perfect for junior to blind other children or the family pets… When the toy’s cheap plastic trigger broke I saw my opportunity to rob it for parts. The laser unit itself is encased in a small copper cylinder about one cm long. The business end has a small window, and the other end has two small wires to power it. It runs on three watch batteries. I chose to mount the battery compartment so the upper receiver normally hides it.
The laser is mounted in a plate cut to the same profile as the end of the P90 (just below the flash-hider). Although the real-steal version may be metal, I chose to use black plastic from an old drill gun battery case because it’s similar to the material the P90 body is made from and you can use solvent glue on it. I used the same material to make a yoke for the back of the laser to sit in. Three screws feed in through the plate to support the yoke, and springs allow the yoke to float so that fine adjusted to aim can be made after installation. You adjust the laser's aim by turning the screws on the front plate.
This is the front plate, screws, and yoke...
Following is a view of the plate, laser, and yoke assembly... The screws have been cut down due to the limited space up front in the P90 receiver.
Following view is the rough cut outs in the lower receiver to accommodate the laser assembly and the battery housing...
Next view is the laser assembly and battery holder installed in lower receiver. The battery holder is just a small plastic box deep enough to accommodate three watch batteries. The batteries are forced against contacts by the force of a spring like any typical battery holder. I didn’t care for the look of the holder which came with the toy pistol, so I scratch built a new one in black plastic… but one could just use the holder that came with the toy. I robbed the contacts and spring (with the wires already attached) from a scrap AA battery holder.
It’s a simple matter to remover the trigger assembly from the P90 lower receiver. This gives you access to the inside area where the push button is mounted. With tweezers one can slide the wires underneath the trigger seat into the front body section. The push button was acquired at the local Radio Shack/Source for 4 bucks and is installed with a small rubber o-ring to help match the curve of the P90 body. I positioned it so you can hold the P90 comfortably whether your finger rests across the button or not.
After a few evenings work and a careful set-up the result is pretty sweet and I can’t wait for my next CQB engagement...
Obligatory Warning: Laser-sighting devices are dangerous to human eyes. You must use them with caution and not flash a laser sight into someone's eyes. Although we have not had any serious issues, I would not blame a game host for ejecting someone reported to be misusing a laser. Respect your fellow airsofters.
