8 replies to this topic

[forest sharpshooter]

ok well i have a question,im making a spring-action rifel,if i use just the spring and cock it back then put in a stefan and shoot,will i get alot of power?

*if you dont understand what im asking let me know and ill try to explain it better>

[tcorr911]

Well it depends on how big your spring is, the longer the spring the longer the plunger means more displaced air and your dart will go further.

P.S. you should delete you image in your sig because CX doesn't like that.

[Carbon]

Are you asking if just the force of the spring is enough to propel the dart, without using an air plunger? If that's the case, then nope. I believe the only Nerf gun to do that is the pen blaster (which is pathetic). All Nerf guns work based on air pressure - whether that pressure is created from a pump or a plunger.

[Flaming Hilt]

Well actually, I would say yes.

I made a crossbow using a bungee cord, and it got 30 ft (I never posted it 'cause I'm giving it a plunger... but... the point is, it can work). Of course, I had to cock it with both arms against my chest, and it bent the nail I was using as a catch... but, it's possible. If, that is, you're okay with 30 feet.

I would reccomend, however, just using a plunger. First off, you don't have to use as strong a spring and it'll be possible to cock; secondly, you get more air for your distance (ie, just using a spring gives you "air" the length of the spring, but using a plunger gives you the volume of your pressure chamber... which, I guarantee, is anywhere between 10-100 times more).

[Carbon]

I made a crossbow using a bungee cord, and it got 30 ft

You're right...bungees can be pretty cool, as davidbowie's KISS series amply shows.

I would reccomend, however, just using a plunger. First off, you don't have to use as strong a spring and it'll be possible to cock; secondly, you get more air for your distance (ie, just using a spring gives you "air" the length of the spring, but using a plunger gives you the volume of your pressure chamber... which, I guarantee, is anywhere between 10-100 times more).

Plungers don't gain over bare springs because of increases in air volume (example: the FAR spring is roughly the same diameter as the PC), it's because of how quickly the stored energy is released.

In the case of a spring, it stores energy when it is compressed. The energy is then released over the entire length of travel. Now, if a plunger is used to create pressure, the time in which the released energy acts on the dart is decreased; friction holds the dart in the barrel, pressure builds up behind the dart, until it overcomes the dart's friction in the barrel. This is a faster energy release than just a spring, so it goes further. The less time it takes for energy to act, the more distance you get.

At least, that's how I believe it works. Physics classes were a while ago.

Edited by Carbon, 23 August 2006 - 10:52 PM.

[Flaming Hilt]

Oh. Crap.

Beaten down yet again. *cries*

[davidbowie]

Actually, i think there is something to what FH said. Even though the FAR's PC is about the same diameter as the spring, it's twice the diameter of the barrel. Since a bare spring isn't pushing any air, there's no relation between spring diameter and power. There will be very little difference in performance between 1" and 8" diameter springs of the same stroke and strength if they are directly pushing the dart.

A direct spring pushes the dart its own length of travel. A (larger-than-barrel-size) plunger puts out a large volume of air, which displaces an equal volume in the barrel, which will have a length much longer than the travel of the plunger. It acts much like a lever, except that the compressibility of air takes some of the immediate oomph out of it.

I think the best way to power a gun with a spring, period, would be to use a lever or block-and-tackle setup to give a direct spring higher speed and less torque. It would be like having a plunger gun with a 1:1 ideal ratio.

[forest sharpshooter]

ok,

1.yes i know that you have to use an airplunger.......
2.and basically what i was asking was that depening on what kinfd of spring i used would make a difference.

[Pineapple]

...P.S. you should delete you image in your sig because CX doesn't like that.

Good call, spotter!

*poof*



-Piney-