The darts (somewhere between 24 and 32 of them) are loaded against a set of rubber-bands that should be able to shoot them outwards 10-25 feet. Thus giving you an effect radius of 20-50 feet.
It's made out of the spindle packaging that CD-R/RW & DVD-R/RWs come in, but the design will only work with taller stacks that have the space needed to orient the darts sideways. A decent amount of space is needed for the spring and the travel length needed for the shell to be moved 3 inches. It works in either direction and if desired you could load darts into only one side for a directional mine.
The AR-15 spring is powerful enough to launch either half of the spindle 3 feet into the air, so it will be perfect for over-coming the friction that all the darts will be adding to the inside. For safety's sake the threaded rod will have a nut on the end that will keep the two halves from coming apart when triggered.
Two triggering mechanisms are possible. The packaging itself includes locking teeth that act as a safety mechanism and that could be undone almost all the way and any disturbing of the mine will set it off. However I'm going to make a center rod to replace the threaded rod that will have a quick-release pin on the end that you can pull out from a string that will set off the spring.
Right now I'm just waiting for supplies to come in the mail. I've already drilled all the holes I need so once I have this tested and tweaked I'll post a construction write-up and video.
(assumed) Supplies needed
+ Packaging from a 100 pack of writable CDs or DVDs
+ Eight 3-inch or 4-inch length UNC #8-32 threaded rods (mcmaster part# 95475A338)
+ A Bunch of 1/4" length #8 nylon spacers (mcmaster part# 94639A401)
+ A Bunch of #8 steel washers
+ #8-32 hex nuts (mcmaster part# 94812A114)
+ AR-15 Carbine spring (or decent substitute because anything with the right compression rate that will fit over the spindle will work fine)
+ Two junked CDs or DVDs that you can drill 8 holes in
+ A 1lb Bag of 3-1/2" Lg X 1/4" Wd, Size 64 Rubber bands (mcmaster part# 12205T55)
+ 24-32 2-inch length stefans
+ 1/2" OD aluminum or plastic rod (not sure what length yet)
+ some #6-32 screws
+ PETG Clear Tube 5/16" OD, 3/16" ID (mcmaster part# 9245K15)
Edited by CaptainSlug, 19 February 2007 - 08:31 PM.