I liked the idea of an adjustable laser pointer like that designed by ouis_, but wanted something a little more compact and which would not get in the way of any other sights. After much messing around in Tinkercad and leaving very little of the original design intact, I've come up with this self-contained unit for mounting on the side rail of those few blasters that had them.

To build this, you will need the following:
• M3x20mm bolt, washer (placed between laser holder and rail adapter) and nut ideally nylock) for securing the height adjustment
• M2 rod for the pivot (ideally 20mm, though a 10mm will work).
• 12mm diameter focusable laser module (I used a 650nm 5mW unit)
• DC 30V 1A mini self-locking push button switch (model 1208YD)
• 14500 Lithium battery
• Two M2x14mm bolts to attach the battery cover (M2x20mm should also work)
• An old spring for the negative terminal (I scavenged one from an old pen)
• Something for the positive terminal (I used a length of braided copper solder wick)

Two different versions have been uploaded. One with the laser holder and battery compartment as a single piece that will require supports, and two separate pieces that can be printed without supports (and in different colours) but will need gluing together.

The original design for the mount fit perfectly on the Rapidstrike, Demolisher and Motofury. However, I've had to create a new design for the Rayven/Rayvenfire to allow it to mount forward of the wall that exists in the tactical rail. This Rayven modded adapter will also fit the Stampede. Neither design will fit my Vulcan though, as that seems to have a thicker rail, so at some point I might get around to making yet another adapter variant for that. Your results may vary depending on the tolerances of your printer and/or the vagaries of Hasbro quality control. If you have success with mounting to a different blaster then please leave a comment or post a make.

As a final note, I assume anyone with the technical ability to put this together will have enough common sense to know how to use it safely and legally.