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First airgun, 40bar/580psi (damage vids) (Updated)

Posted: Thu May 19, 2011 11:54 am
by Tobin
The updated version:
Image

I have now change the gun a bit:
-I removed the secondary chamber
-Reduced the pilotvolume
-Increased the chamber volume from 340cc to 460cc
-Added a grip and a screen to the gauge.
-Paintjob
-Improved piston


Image


Old version:

Image

This is my first airgun which I got to work fine a few days ago. Previously I made a potato gun but started to make this airgun because of my interest but also because ive got tired of my potatogun's unreliability

The idea then was to build a gun that can used 40 bar, got a 20mm bore and can fire multiple shots without hooking it up to the compressor al the time.

The gun has a 1 1/4 tee as pistonvalve, the piston is 3 cm in diameter and the sealing face has a 20mm opening. I have fired it up to 40 bar.

As you can see in the video, I have two chambers of the gun. The secondary chamber is way too small to fill in the primary now, but in my first prototype, I had a primary chamber of approximately 80cm3. Then I could reload and lost about 4-5bar/ shot. Despite the small chamber the gun was even when the much stronger that I could imagine but i wanted som more power.
The current chamber is about 320cm3 and performing far better. However, the secondary chamber are now useless. I will probably remove it and replace it with a quick connect so that I can link the rifle to a large fire extinguisher through a hose instead.

Things i will do:
replace the secondary chamber
reduced the pilot volume
ad a stock from a old airrifle
maybe a lighter piston, at the moment the piston is made of aluminum.
Some paintjobb.
Move the stupid placed male connect.

The damage video:
[youtube][/youtube]

Posted: Thu May 19, 2011 1:14 pm
by qwerty
Nice gun! very good build quality for a first and i must say, the damage is very impressive. Good penatration on that wood (no jokes please :roll: )

Posted: Thu May 19, 2011 1:25 pm
by Tobin
qwerty wrote:Nice gun! very good build quality for a first and i must say, the damage is very impressive. Good penatration on that wood (no jokes please :roll: )
Thanks. When i shot my first nail, at 40 bar, i was stunned because i thought, -Well they will maybe pierce a 15mm piece of plywood if Im lucky. Later it actually pierced 3cm of wood when i fired at only 5 bar!


Btw, how to get a picture of the gun shown left to my topic in the topic thread?

Posted: Thu May 19, 2011 2:52 pm
by clemsonguy1125
Upload it as a thumbnail, there is a option in the uploader. Nice gun.

Posted: Thu May 19, 2011 3:02 pm
by Doctore
Nice!!!
I love it.Is it accurate at 40 bar???

Posted: Thu May 19, 2011 4:14 pm
by Tobin
Doctore wrote:Nice!!!
I love it.Is it accurate at 40 bar???
Havent tested accuracy yet. Dont know if we can call these kind of guns accuraty. Its rather the projectile that is accurate or not i think? But i shall make a projektile with fins and make some tests some day. Im happy if i can hit a 33cl can at maybe 5-7m.

Posted: Fri May 20, 2011 4:08 pm
by urgle the danish cow
nice job especially for a first

Posted: Sat May 21, 2011 5:00 am
by Tobin
Just some questions.
How much pressure can the brass fittings safely handle? Is 50 bar safe? I think especially because of my piston. I want to keep the aluminium piston if i will increase the preassure because of its durabillity. But the piston do weight about 50 grams i dont know if that is safe then it slam back at the brass fitting. I do have a small bumper consisting of a 3mm tick layer of melting glue but not more.

Posted: Thu May 26, 2011 7:16 pm
by daniel0663
How much pressure can the brass fittings safely handle? Is 50 bar safe?
Personaly, i would NOT use gas type brass fittings at 50bar. :?
I wouldn't trust it my self. But it has been done before several times.
If you are gonna use it at 50bar, MAKE sure you tighten your fittings firmly all the way.

JUST WANTED TO KNOW WHICH AIR COMPRESSOR U USE

Posted: Thu Jun 09, 2011 1:17 am
by HACKERZLORD007
HEY MATE

I JUST WANTED TO KNOW WHICH AIRCOMPRESSOR U USE BECAUSE MY EMERGENCY AIR COMPRESSOR CAN PUMP US 200 - 300 PSI MAX....MY GUN CAN HOLD A GOOD 600 PSI + BUT I CANT FIND A GOOD AIR COMPRESSOR..SO JUST ASKED...THNX MATE!!

CHEERS

Re: JUST WANTED TO KNOW WHICH AIR COMPRESSOR U USE

Posted: Thu Jun 09, 2011 1:31 am
by Crna Legija
HACKERZLORD007 wrote:HEY MATE

I JUST WANTED TO KNOW WHICH AIRCOMPRESSOR U USE BECAUSE MY EMERGENCY AIR COMPRESSOR CAN PUMP US 200 - 300 PSI MAX....MY GUN CAN HOLD A GOOD 600 PSI + BUT I CANT FIND A GOOD AIR COMPRESSOR..SO JUST ASKED...THNX MATE!!

CHEERS

USE THE SEARCH MATE, now if you typed that nicely maybe i could help you

Posted: Thu Jun 09, 2011 4:42 am
by Copperboy
Fan va nice! :P

I also wonder what sort of compressor and chambers are used? And how is the breech is designed?

Re: JUST WANTED TO KNOW WHICH AIR COMPRESSOR U USE

Posted: Thu Jun 09, 2011 5:39 am
by HACKERZLORD007
Crna Legija wrote:
HACKERZLORD007 wrote:HEY MATE

I JUST WANTED TO KNOW WHICH AIRCOMPRESSOR U USE BECAUSE MY EMERGENCY AIR COMPRESSOR CAN PUMP US 200 - 300 PSI MAX....MY GUN CAN HOLD A GOOD 600 PSI + BUT I CANT FIND A GOOD AIR COMPRESSOR..SO JUST ASKED...THNX MATE!!

CHEERS

USE THE SEARCH MATE, now if you typed that nicely maybe i could help you
I tried searching google,yahoo and loads of other sites but all i get is heavy duty industrial air compressor!! The one i have is:

http://www.alibaba.com/product-free/216 ... essor.html

It can pump usually to 300 max but it kills the battery so usually i have to limit my shots to 200 psi which sucks....my gun is fully galvenized metal capable of doing 500+ psi but its a pity having a gun which is so capable but lacking the compressor!!!!
Help would be appreciated!

CHEERS!

Posted: Thu Jun 09, 2011 6:33 am
by Crna Legija

Posted: Fri Jun 10, 2011 12:06 pm
by Tobin
Copperboy wrote:Fan va nice! :P

I also wonder what sort of compressor and chambers are used? And how is the breech is designed?
Tackar ;)

The compressor is a fridgecompressor. The chamber did i weld myself to get what i wanted. Found out during the welding that there was very hard to get it air sealed to 40 bar with arc welding. Breech? Do you mean there i load the bullets?