12G Alarm

thingiverse

I wanted to create my own version of a 12G Alarm because I had a package stolen from my porch last Christmas, so I designed this one myself. In addition to the three components shown, you'll need a suitable spring, some split pins, a roofing nail, and a bolt that fits the bolt carrier. Author takes no responsibility for any and all usage of this device. Here's how it works: - Mount the main assembly on a board or a suitable location. - Drop a 27mm roofing nail (1.25 inches) into the main tube, making sure it threads into the recessed section and pokes through to the bottom. - Using a bolt that fits the hole in the bolt carrier (the piece with the hole on one end), screw in a bolt so that it forms a hammer end. The head must enter the main tube. - Insert a split pin into one of the lower holes (different holes give you different compression options). - Drop in the bolt carrier; it should not be resting on the split pin, with the bolt head towards the roofing nail. - Drop in a spring: mine is 35mm uncompressed and has a diameter of 10 mm. - Insert the compression pin (the one with the holes on the side) and push down to compress the spring. - When you have a hole aligned and the spring compressed, insert a second split pin. - Tie a string to the lower split pin and attach the other end to a post, object, or bait box. - Insert a 12G Blank (NO PELLETS!) into the base plate. The pin should now be resting on the primer, and you're ready. When the string is pulled, the lower pin is removed, and the bolt carrier is propelled towards the roofing nail by the expanding spring. If your spring is decent, there should be enough force to drive the roofing nail into the primer and set off the PELLET-LESS shell, hopefully teaching any would-be thieves a lesson.