Sponge Nerfer

Alright, I got a lot of work done over that past couple of days and pretty much finished the gun. I just finished off a few easy seals and now the gun is fully operational. I decided to take testing slow, today I only looked into which materials burst well and at which psi they did so. After having a lot of fun setting off different combinations of materials (4 sheets of tinfoil goes off at 100 psi, BANG, pretty much shook the whole neighborhood ) I discovered that two sheets of tinfoil goes off around 40 psi, just what I wanted it to be. Here are some pictures of my "test station" and the busted pieces of tinfoil.





I will start messing with the triggering system soon enough.

Questions? Comments?

-sponge

So today I sawed out a breach for the gun and got the whole barrel assembly working.

Here is most of the gun put togethor:



Things are going well, but I need a surefire way to get a shrader valve to seal onto 1" pvc pipe. If anybody knows of a good way to attach shardervalves to pvc, and get a nice seal, PLEASE let me know. One leak could really mess up this gun.

-sponge

Well thanks for all of your quick responces. Most of it seemed positive which is always nice, here are my answers to some of you questions and comments.

1. Rubber membranes and cut out milk jugs seem like they would require far too much power to burst. Im not looking to kill bulls at 2000 yards. However badger's advice of using heavy duty trash bags seems possible. I plan to just have fun with trial and error for a little while until I find something perfect.

2. Last man alive, not too sure what you were talking about with your video plan. Dunno what a Nerf milsim movie is, if you want to try to explain it to me that would be fine.

From all of your posts I got the idea that you all wanted to have a better idea of what the gun might look like in the end. So I decided to put a little more meat on its bones (make the tank and put it on the valve) to give you a better idea of what im shooting at.

Here she is!



Next to a titan rocket for size comparison:



It clearly still has some work do be done, I need shrader valves for both the tank and the tiny burst chamber. Also it needs a barrel. None the less this project is well on its way.

Questions, comments?

-sponge

TRIGGERED burst valve, read it again.

-sponge

A very crudely drawn, triggered burst valve. I am using this in a project im working on currently.



RED: Tinfoil burst plate

PURPLE: 1" union, to hold the tinfoil burst plate

BLACK: 1" PVC pipe

BLUE: Shrader valve, for input. (same kind of valve you see on a bike, or car tire)

GREEN: 1/4" blow gun valve used as a pilot

HOW IT WORKS:

1. Lets asume that the pressure at which the tinfoil burst plate breaks is 40 psi.

2. Pump up the chamber in between the two burst plates to 20 psi, the plates do not break.

3. Pump the main tank of the gun up to any pressure between 40 and 45 psi. Because of the 20 psi pushing back at the tanks pressure the psi that the burst plates have to endure is still only around 20 psi.

4. After loading a dart the gun is now ready to fire.

5. Pull the trigger of the blow gun valve. This will cause the pressure inside the small chamber between the burst plates to become nearly zero, thus alowing the 40 psi tank to press its entire force onto the burst plate. Both burst plates break and the dart you have in your barrel is gone to hell.

-sponge