paper for a drill template. Drill the holes into
the red Plexiglas® using a 5/16” drill. Punch
the screw holes into the styrene target. Tap
the four corner holes of the board using a
6-32 tap. Place the styrene on top of the
Plexiglas. Using four white nylon screws,
mount both to the board. Place the Plexiglas
directly on the photodiodes; do not over-tighten the screws.
Machining the Photon
■ FIGURE 5.
You will need a lathe or find a friend that has one.
Use a soft plastic such as Acetyl or Deldrin, or even oak.
Do not use Lucite. A 5/8” rod is milled to the dimension
of the bore of the gun. The tube has a total length of 3”.
The end is knurled so you can grasp it to remove it. (For
2” barrels, seen Hints and Tips on the NV website.)
Follow this Method:
1. Knurl 3/8” of one of the ends of the 3” plastic. This
will be the end where the laser will go.
2. Center drill both ends.
3. Chuck the tube’s knurled end and use a center on
the tailstock on the other end.
■ Target Schematic.
May 2010 33