Instructables.com - Build A Net Gun

Step 11: Et cetera
Thanks for all the positive responses so far. I will post updates to the build and attachments here. I came up with the safety after negligently discharging a net while filling
the pressure chamber. It is so easy to make, every responsible net gun owner should have one. I developed the tennis ball attachment while working on an older net gun
design that had a 2" net holder, it is a lot of fun for the $3 it costs to make.
Mechanical Trigger Safety
A very simple mechanical safety that will prevent the net gun from firing in the event the trigger is unintentionally actuated.
Supplies
Scrap 1/2" pvc pipe
Small rubber band
Assembly
Cut a short length of 1/2" pipe, probably between 1/4" and 3/8", it will depend on the specifics of the blow gun. It needs to fit under the blow gun handle and be
thick enough to prevent the handle from depressing the valve underneath. You made need to cut a wedge out of one side of the ring to allow it to slip under the
handle.
Loop rubber band around one end of ring, and through itself. Take the free loop of the rubber band and slide onto the body of the blow gun valve.
To put ON SAFE, slide ring around brass valve underneath lever Fig 1. To take OFF SAFE, slide ring down and out of the way of valve and lever Fig 2.
Tennis Ball Launcher
The inside diameter of a 2" PVC coupler fits a tennis ball perfectly. If you own a ball chasing canine, this will forever associate the bang of compressed air with the joy of
the chase.
http://www.instructables.com/id/Build-A-Net-Gun/