9 replies to this topic

[ShadowTank]

I'm trying to do some differnt "new" mods that have never been done before, but before I do so, I'm trying to figure one thing out which may have an impact on the design of the mod.

How does the Rapid Fire 20 recoil work? THat is, what causes it to spring back once air is released by the trigger? it pushes forward, then recoil backs because of the spring? Is there some kind of pressure release valve, that it reaches a certain point, and the air pressure "escapes" causing the assembly to recoil back? I don't want to have to take it apart because I fear it will no longer work if I do, but i'm hoping someone has figured this out, or knows, perhaps by discecting one that no longer worked?

Thanks!

Shadow Tank

[CaptainSlug]

Is there some kind of pressure release valve, that it reaches a certain point, and the air pressure "escapes" causing the assembly to recoil back?

That's pretty much it. It's a combination and an air cylinder and a regulator. The compression rate of the spring set the pressure level at which the piston actuates. And once it reaches the most forward position it gets past an o-ring and the pressurized volume of air escapes. This simultaneously fires the dart and allows the spring to push the piston back to it's starting position.

[Z-man12]

Well I am currently working on adding another spring to mine, we will see how well that works when I get it done.

[SHADOW HUNTER ALPHA]

Be careful. The piston isn't exactly the most durable thing in the world. Also, the more springs that you have, the greater the pressure needed to move the piston. This is a bittersweet result, because it also means that the gun needs higher pressures to operate than its typical level. You may want to opt for an external tank.

[Z-man12]

Be careful. The piston isn't exactly the most durable thing in the world. Also, the more springs that you have, the greater the pressure needed to move the piston. This is a bittersweet result, because it also means that the gun needs higher pressures to operate than its typical level. You may want to opt for an external tank.

I already am working off a different tank. And I am aware the piston is weak, Thats why the spring is going in the place it is. This is all part of my little "secret project"

[ShadowTank]

The reason I am asking, is I am doing a Major Mod to this, by possibly making my own "Ammo Clip" that will be a larger radius to hold more nerf darts. However, to make it work, i need to change the "rate of fire" or maybe better explained, the timing of the advancing mechanism. Understanding how it works would enable me to possibly modify it without destroying it. ANy thoughts?

Shadow Tank

[ShadowTank]

Is there some kind of pressure release valve, that it reaches a certain point, and the air pressure "escapes" causing the assembly to recoil back?

That's pretty much it. It's a combination and an air cylinder and a regulator. The compression rate of the spring set the pressure level at which the piston actuates. And once it reaches the most forward position it gets past an o-ring and the pressurized volume of air escapes. This simultaneously fires the dart and allows the spring to push the piston back to it's starting position.

Any idea on what is the distance it goes before returning to it's original position? I'm having a difficult time figuring that out.

Thanks!

Shadow Tank

[CaptainSlug]

The reason I am asking, is I am doing a Major Mod to this, by possibly making my own "Ammo Clip" that will be a larger radius to hold more nerf darts. However, to make it work, i need to change the "rate of fire" or maybe better explained, the timing of the advancing mechanism. Understanding how it works would enable me to possibly modify it without destroying it. ANy thoughts?

You have to change the degrees of rotation that each piston cycle rotates the turret. And you obviously have no idea how hard it is to design such a change. You would have to make your own ratcheting clutch as well.
My expert opinion is: to forget it.

Edited by CaptainSlug, 10 September 2007 - 10:00 PM.

[ShadowTank]

Using a simple CAD program, I have already calculated the necessary angle for each barrel, as well as a different type of advancing mechanism. I am using the piston to go back and forth, but the method of advancing the barrel/turret is differnt than the original design.

After posting this, I later on realized that it doesn't matter how fast or slow the piston rate is. What is important is the teeth are aligned properly so when the piston advances the turret to the next position the hole lines up with the piston/cylinder when the CO2 is released.


Because of the tight spacing between the teeth on the turret, I do not need to use a lever/spring assembly for the advancing arm. I am usign a straight single piece that will advance the turret. It is difficult to explain in words how it will work. If I have the free time, which i don't right now, I will scan a copy of the sketch I have for the design of this arm to show how I plan on doing it.

RIght now, my larger consern is as each time it "fires" both cylinders will be pressurized. When they release, there is no place for the CO2 to go with one of the cylinder's. THe issue of backflow and causing damage to the piston/cylinder assembly is one I don't know if it would happen. or, since there is some space, no matter how small, it is not a perfoect seal between the cylinder/piston assembly and the turret, so the CO2 does have a place to displace, though not through the turret.

BTW, when I first looked into using CO2, I was told it could not be done and I should abandon the project. Well, I went ahead anyways, and through many tirals and errors, it did eventually work. The same is most likely going to be the case here too.

ShadowTank

The reason I am asking, is I am doing a Major Mod to this, by possibly making my own "Ammo Clip" that will be a larger radius to hold more nerf darts. However, to make it work, i need to change the "rate of fire" or maybe better explained, the timing of the advancing mechanism. Understanding how it works would enable me to possibly modify it without destroying it. ANy thoughts?

You have to change the degrees of rotation that each piston cycle rotates the turret. And you obviously have no idea how hard it is to design such a change. You would have to make your own ratcheting clutch as well.
My expert opinion is: to forget it.

[SHADOW HUNTER ALPHA]

Avoid using CO2 in plastic guns at all costs. The high pressure and low temperature will cause the plastic(s) to shatter soon.