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Member Since 06 May 2004
Offline Last Active Mar 31 2007 05:28 PM

Posts I've Made

In Topic: Rotary Breech?

15 May 2006 - 03:35 PM

A butterfly valve would require much more precision in the design, since it must be entirely closed before the valve can open; but, if you used a ball valve and made the inside of the "ball" the chamber, you could use the ball valve as the only valve, or if you wanted a semi-auto or full-auto nerf gun, as one of two valves. Plus, from what I see on mcmaster-carr a butterfly valve would cost at least 5-10 times as much as a ball valve.
However, if you were going to use a butterfly valve anyways, you might as well make your own rotating piece for the nerf gun. That way you would still need two valves in addition to the rotating chamber, but it could have much less friction like a butterfly valve and cost a lot less than any other choices.

In Topic: Rotary Breech?

15 May 2006 - 02:23 PM

Use a ball valve for the chamber, and set up a system of solenoid valves and an electric motor to make the thing full/semi auto. You would really only need one little solenoid, since the ball valve would work as the actual "firing valve".The only proble would be finding a gear motor strong eough to turn the ball valve quickly enough to allow a decent rate of fire.

In Topic: Nerf Grenade

09 April 2006 - 04:05 PM

Doesn't he want an airburst grenade, not an impact one?

Anyways, just get rid of the nose cone part and stick some string or wires going from the carboard sliding piece through slots, or holes for string, inside an open compartment in the back instead of the fins. Then just have a piece of brass/springsteel attached to the base of the compartment at one end, then bent up with a suction cup on the other end, and a parachute attached to the wires/string from the cardboard slider, and then when the suction cup releases(hopefully during flight) the spring steal will pop up, flinging the parachute out the back. The parachute will catch the air and slow down, pulling on the strings/wires atached to the sliding piece, which will be pulled back, letting the darts pop out in a wide spread and fall down on your opponents. As a bonus, the whole thing will slow down and fall gently as the parachute will still be attached to the casing, thereby increasing the safety.

Edit-Ouch, I missed three posts while I was typing. And CS beat me to the parachute on his design idea. Oh well.

In Topic: Nerf Grenade

09 April 2006 - 03:43 PM

GeneralPrimevil, is your grenade just 1" 200psi tube with a bag as a parachute? if so, use a cardboard tube, that alone will make it much safer. Also, if the momentum of the darts is just flinging them out the front of the tube when the "parachute slows it down, isn't it more like discarding sbot shotgun round than a grenade? Oh well, I thought you wanted an airburst type thing but anyways, the way you are doing this the safety and range are interconnected, so it is probably not the best design. If it was an airburst grenade where you shoot it over the heads of a cluster of opponents, then it would inherently be much safer since the darts would be taking a much different path than the casing, unless you use my design, in which case the casing will only be falling from the sky, not shooting at people. This means that you only have to protect people from accidental hits with the casing, still a problem, but as long as you make sure it can't seriously hurt anyone a few painful hits once in a while by accident shouldn't be a huge problem.

Anyways, I just tested my idea, but without a timer and thrown by hand. It worked wonderfully, bt without a timer the darts came out as soon as the parachute caught the air and opened, which was quite soon, about 15-20ft up from my best guess when I threw it straight up.

In Topic: Nerf Grenade

09 April 2006 - 01:15 PM

Ok, you didn't say my name, but I'm annoying, so here it goes. Use a cardboard tube and glue/tape a cardboard disk to seal off one end of the tube. Next take a cardboard circle that fits inside the tube and attach a string to the center of it. put another disk on the string, but loose so it can slide up and down. Attach a toy parachute to the end of the string, or a streamer it you want a less sudden release. Get an old digital watch with a timer and hack it so instead of the alarm you get a weak elecrical siganl when it goes off. Get the proper relay and a small battery plus a small hacked servo/gearmotor and glue it all to the sliding disk with a spring and a catch activated by the gearmotor/servo.(the disk is sliding on the string to make it easier to load darts it.
To use it just put the first disk it to the bottom of the sealed off tube, pour stephans in, put the disk with the timer, spring, catch and streamer/parachute in and tuck the parachute on the spring. Set the timer and launch it.