9 replies to this topic

[pigeon4]

I've got an idea on firing using CO2.

Basicly, this is an idea i got while looking at a Tompson sub-mechine gun (tommy gun). I dont know alot about CO2... so this is just a guess.

Picture here

The Black thing that kinda looks like a CO2 tank is a. . . .You guessed it! A co2 tank!

In back of it is a spring

In front of it is a bar going throgh the PVC. Attached to it is a rod/pole.

Then some fittings to reduce the size of the PVC down to 1/2".

Next is two 90* 1/2" elbows.

Then comes the barrle, with some kinda magazine on top of it.

I'm not sure how the mag will work. . .  this is just my idea about firing repeted shots of CO2.

---

What happens is the CO2 tank is pushed forward by the spring. The Rod/pole presses the pin on the CO2 tank releasing the CO2. The CO2 travels throgh the elbows to the barrel and launches the dart. The force of the CO2 being released blows the tank back and compreses the spring then to whole cycle starts over again.

It's just an idea...
What do you think?

I thought this was a rather good concept. I'm going to try to make something similar and I'd like your feedback as to whether you think it'll work or blowup in my face. I'm hoping mine will have a large gravity feed clip and the CO2 cartriage wil be held within 2 1/2 different chambers. One inside another insde a partiale cover. I hope to get my blueprints up soon.
Mine will also have a trigger.

[GeneralPrimevil]

Welcome to NerfHaven. Enjoy your stay.

Thompson's design for a sub-machine gun worked just like that. I personally would use a gas design, not a blow-back system. Gas systems are a bit more complicated, and also require more gas in order to cycle the bolt back and load a dart.

I personally think the design sucks. PVC is not strong enough to hold any kind oif high pressure substance, suck as marketed CO2. Also, this is more my fault, but if the tank had a release valve like that, which looks similar to the one on the end of a RF20 or PC bladder, then the tank would be rather large, which would mean it needs a rather large spring. Also, I'm not sure then if the tank would blow back.

How would the trigger work? Would it be like a pin that goes in front of the tank and stops it from going forward?

[pigeon4]

the co2 would have collar around it made of something and the trigger would be made like a normal nerf trigger. pulling the trigger makes it go down release it and it pops back up in front of the collar. I'd really like to have this idea work in some way whether it be co2 or not. I'd like to here your ideas for the gas design.

[Vintage]

It's not likely that this concept would work as-is. The dart that is to be fired is not sealed in the barrel. This means that most of the co2 will escape out the magazine and not launch the dart any large distance.

The spring is the important part here. If it is too strong, alot of co2 will be wasted on each shot. It it is too weak, the dart gets poor distance.

Also, depending on how the spring governs the blowback, the gun might have a high ROF with little blowback force, or it might kick really hard and have a slow ROF.

So, the main things to work out would be:
1. Find a trigger system that would work efficiently.
2. Find a spring that controls the ROF/velocity just right.
3. Find a way to seal each dart in the barrel before each shot.

~Vintage

[pigeon4]

yea I was thinking of sealing the barrel earlier. i could put something over the breech if its a blowback and have the breech cover conncted to the part that slides back, that way after every shot the gun would reload (slides back) and reseal the barrel (slides forward)

[GeneralPrimevil]

Have you ever seen an RF20? The internals of mine (since the barrels don't rotate) are going to now be used for a mag-fed homemade auto, or at least the design basis. When the gas unit (the thing that moves on the top of the gun) moves forward, it will act as a bolt, sealing the dart in the barrel. After it fires, the unit moves back, allowing a dart to be loaded. Then it moves forward, shooting the dart. Unfortunately, the darts would have to be about a half inch in length and diameter, so this probably won't work, unless I completely make homemade internals.

If you wanted to completely bypass the spring and bolt design, you could simply attach the tank to a lever that, when the trigger is pulled, will turn the force oin the oposite direction. Here's a quick diagram:
___________
l l\__
l tank l __l
l___________l/
\\\\
_\\\\_ ----lever
l_ ___l
/ /------trigger
\_\

Good enough. Then, if you use the 3DBBQ barrel adaptation (without tipping the gun forward), and some creative breech work, you could have a fully automatic nerf gun.

If you really want to use CO2, then you have to buy the appropriate type of steel tubing. Get the stuff with the high PSI rating, and I mean really high.

<EDIT> Should've previewed that post. Then I would've know that my illustration was messed up. The design of it I can't explain to well.<EDIT>

Edited by GeneralPrimevil, 03 June 2004 - 05:25 PM.

[nerfspecialforces]

I would make a tommy gun looking thing for my auto gun.It Looks like a RF20


[ ]-----()--
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DON'T MIND THE BLUE
Green-tank
Yellow-barrel
Ogange-ammo holder

Ok, here's how mine would work: the tank on my gun would be bigger, and have a trigger release valve. The gas would go down the tube into the ammo holder(Wheel thing).The ammo holder would have a ring clip on the inside.The tubes that have darts in them would have a small flap in the back on the left that would stick out into the barrel. As the gas comes through the tube, it pushes on the flaps and spins the wheel just like a windmill or propeller. A small section of a dart would stick out and catch a small metal flap to stop the turning when the gas stops shooting darts.(make any sence? )IN conclusen, the design turns with gas and shoots with gas.(lost yet? )

[pigeon4]

I've been wanting an rf20 but I haven't discectd mine yet. Afraid I'd mess it up but I hope to be gettimg another one in the near future. If I could make a larger version of its workings I think I could apply it easily to my machine gun

[seirus]

The issue with the magazine being fed by gravity is that it can easily fault. My magazine design is a similar concept to any magazine fed firearm. Shells (1/2 in PVC) are fed upwards by a spring, whereupon a bolt slides back. When the bolt jams forward, the shell is slipped from the magazine. Then pull the bolt back and presto.I haven't been able to build an extractor claw yet, so I just take the shells out by hand. I hooked this system into my H2 Shell and powered it using Co2 Mini cartridges. It works just dandy. If I can figure out a means of creating sufficient gas to propel the bolt back automatically and a extractor mechanism, then it'd be fully automatic. Whoot!

[pigeon4]

The issue with the magazine being fed by gravity is that it can easily fault. My magazine design is a similar concept to any magazine fed firearm. Shells (1/2 in PVC) are fed upwards by a spring, whereupon a bolt slides back. When the bolt jams forward, the shell is slipped from the magazine. Then pull the bolt back and presto.I haven't been able to build an extractor claw yet, so I just take the shells out by hand. I hooked this system into my H2 Shell and powered it using Co2 Mini cartridges. It works just dandy. If I can figure out a means of creating sufficient gas to propel the bolt back automatically and a extractor mechanism, then it'd be fully automatic. Whoot!

wow, did you use a regulator? Can you post a pic