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Posted: Mon Oct 01, 2007 1:42 am
by Novacastrian
You have me by the short and curlys with your "rough test" , you were using a coin right? :lol:

Edit: If your theory IS true why don't "they" (i hate it when people say that) use this idea in munitions?

Posted: Mon Oct 01, 2007 1:47 am
by Marco321
Lol, short and curlies.
Yeah i used a Australian 20c coin.

Posted: Mon Oct 01, 2007 1:50 am
by Marco321
What do you mean munitions? Like shooting out bullets?
Well because I'm not getting something for nothing, I'm applying the same speed to a heavier object, i am effectively giving the heavier object more energy because its harder to bring it up to the same speed as a lighter object.

EDIT: Sorry double post

Posted: Mon Oct 01, 2007 1:50 am
by Novacastrian
What we really need is for JACKSSMIRKINGREVENGE to get off his butt and reply to this thread!

Posted: Mon Oct 01, 2007 1:51 am
by Marco321
I replied to your munitions question thing ^^^
Novacastrian wrote:What we really need is for JACKSSMIRKINGREVENGE to get off his butt and reply to this thread!
Lol yeah

Posted: Mon Oct 01, 2007 1:58 am
by Novacastrian
I got it up to "bullets" are you drinking?

Posted: Mon Oct 01, 2007 2:30 am
by Marco321
Novacastrian wrote:I got it up to "bullets" are you drinking?
??
What yeah mean? Spell check was on, i just double checked it. It seems legible and coherent.

Posted: Mon Oct 01, 2007 2:32 am
by jackssmirkingrevenge
Novacastrian wrote:Edit: If your theory IS true why don't "they" (i hate it when people say that) use this idea in munitions?
There is a weapons system that uses a similar mechanism to a nailgun - the Russian SP-4 "closed circuit" cartridge fired by the PSS pistol. The idea is to make a noiseless shot by not allowing the propelling gasses to leave the cartridge. This means that the bullet is not actually pushed by the gas itself but by a piston. It works like this:

Image

unfired cartridge

Image

firing

Image

piston jammed against cartridge, projectile fired.

In the case, the piston doesn't strike the bullet in the manner of a golf ball, but accelerates it slowly like a sabot. The way I modified the nailgun is in the same manner, the coin is already touching the blade of the piston when it starts to accelerate. I suppose I could make some comparative tests with the coin some distance away from the blade but since the coins fly so erratically it would be hard to tell the difference in performance.

edit:
What we really need is for JACKSSMIRKINGREVENGE to get off his butt and reply to this thread!
lol sorry, I was busy showing the coin launcher to my work coleagues :P

Posted: Mon Oct 01, 2007 4:12 am
by Novacastrian
So am i right or what? :?
In the voice of Pualine Hanson "Please Explain" :D

Posted: Mon Oct 01, 2007 4:29 am
by jackssmirkingrevenge
Not very scientific but I did some tests with the coin launcher, I fired a few shots with the coin starting out touching the blade on firing, and a couple more with the coin an inch or so away, giving the blade time to accelerate before striking the coin. There was no discernable difference in penetrative power.

Posted: Mon Oct 01, 2007 4:33 am
by Novacastrian
Hmm, just as i thought, :)

Posted: Mon Oct 01, 2007 5:00 am
by jackssmirkingrevenge
As I said though, it's not a very scientific test. What I'd need to do is chrono some spherical projectiles and see the difference. The nailgun platform is a pretty versatile one however, I was thinking on making a wider base to turn it into a CD launcher :D

However, this could actually be the key to my full auto project. My idea would be to remove the nailgun's hammer piston and replace it with some sort of blowback/blowforward mechansim. This would give me semi-auto fire and hopefully more power than I was getting from my previous blow-forward efforts (as they were only powered by a blowgun). To achieve full auto it would just be a question of using an eccentric cam powered by an electric motor to activate the trigger.

Posted: Mon Oct 01, 2007 5:55 am
by Marco321
Nice JSM, i reckon it should be slightly faster with it touching the coin, no loss of energy from heat and sound when the piston and coil collide.

All we need now is someone to settle nova's and my decision....

Oh, and nice gun, i really love your ideas, very inspirational

EDIT:
Your "A light, in the dark"
Anyone know where that came from?

Posted: Mon Oct 01, 2007 6:16 am
by jackssmirkingrevenge
Your "A light, in the dark"
Anyone know where that came from?
che?

Posted: Mon Oct 01, 2007 6:22 am
by Marco321
jackssmirkingrevenge wrote:
Your "A light, in the dark"
Anyone know where that came from?
che?
Iron Maiden, the song fear of the dark