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TRUE BLOWBACK (GBB)

Posted: Mon Sep 29, 2008 5:00 am
by i-will
WHEN I FIRST BECAME A MEMBER OF THIS FORUM I WAS EXCITED TO FINALLY SEE WHAT OTHERS HAVE DONE WITH IMPROVISED PROJECTILE PROJECTS. SO FAR I'M NOT VERY INSPIRED. I'M AN AIRSOFT FANATIC SO I KINDA HAVE A HIGH STANDARD WHEN IT COMES TO HOMEMADE WEAPONS. ALL THESE PVC CANNONS AND PEN TUBE STRAPHERS ARE A GREAT WAY TO TEST THEORY BUT THAT IS ALL. GUNS HAVE TWO AREAS TO COVER. THE INTERNALS AND THE BODY. THE PVC CANNON IS LIKE A GUN WITH NO OUTER BODY. I HOPE NO ONE HATES ME FOR SPEAKING MY MIND. I PLAN ON REVEALING SOME SECRETS IN THE WORLD OF HOMEMADE WEAPONS AND AS THE SUBJECT TITLE PROMISES I WANT TO SHOW U HOW GAS BLOWBACK WORKS. THANKS FOR LISTENING.

<a href="http://s90.photobucket.com/albums/k273/ ... anics1.jpg" target="_blank"><img src="http://i90.photobucket.com/albums/k273/ ... anics1.jpg" border="0" alt="Photobucket"></a>
AT REST. BB IN CHAMBER.

<a href="http://s90.photobucket.com/albums/k273/ ... anics2.jpg" target="_blank"><img src="http://i90.photobucket.com/albums/k273/ ... anics2.jpg" border="0" alt="Photobucket"></a>
VALVE OPEN. BB FIRED. BLOW-BACK RAM BEING PUSHED.

<a href="http://s90.photobucket.com/albums/k273/ ... anics3.jpg" target="_blank"><img src="http://i90.photobucket.com/albums/k273/ ... anics3.jpg" border="0" alt="Photobucket"></a>
RAM PUSHES THE SLIDE BACK. THE PRESSURE INSIDE HOLDS THE CYLINDER IN PLACE UNTIL THE VALVE IS CLOSED.

<a href="http://s90.photobucket.com/albums/k273/ ... anics4.jpg" target="_blank"><img src="http://i90.photobucket.com/albums/k273/ ... anics4.jpg" border="0" alt="Photobucket"></a>
THE PRESSURE DISSIPATES AND THE CYLINDER IS PULLED BACK BY A SPRING TOWARDS THE HEAVIER SLIDE

<a href="http://s90.photobucket.com/albums/k273/ ... anics6.jpg" target="_blank"><img src="http://i90.photobucket.com/albums/k273/ ... anics6.jpg" border="0" alt="Photobucket"></a>
THE SLIDE MOVES THE WHOLE MECHANISM FORWARD RELOADING THE CHAMBER

<a href="http://s90.photobucket.com/albums/k273/ ... anics6.jpg" target="_blank"><img src="http://i90.photobucket.com/albums/k273/ ... anics6.jpg" border="0" alt="Photobucket"></a>
BB IS PUSHED INTO THE CHAMBER BEHIND HOP-UP.

<a href="http://s90.photobucket.com/albums/k273/ ... anics7.jpg" target="_blank"><img src="http://i90.photobucket.com/albums/k273/ ... anics7.jpg" border="0" alt="Photobucket"></a>
MECHANISM IS AT REST AND IS FULLY RESET.ALL THIS HAPPENED WITH ONE PUSH ON THE TRIGGER. THAT IS TRUE BLOWBACK. PIS FROM arniesairsoft.co.uk. ANY QUESTIONS?

Posted: Mon Sep 29, 2008 5:34 am
by littlebro05
Think of it this way, it's very hard to make you're own homemade "gas blowback" with hardware materials even with that diagram. You try making one of those and you'll be the gaining fame and glory.

And most of these airsoft guns on these forums are well... low pressure powerful airsoft, with a few exceptions of CO2.

Its too hard to build one of those with conventional hardware materials and you'd need a proper machine to do it. Thats all I got to say.

Although there is one guy who has homemade gas blowback guns, however very costly, can't remember his name :S.

Posted: Mon Sep 29, 2008 5:46 am
by VH_man
this mech is actually very easy to create.... making it compact and air-efficient is the challenge.

Ive done it. It just broke cause i made it out of crappy materials..... lol.

BTW, could you get rid of the All Caps thing? its annoying.

Posted: Mon Sep 29, 2008 5:49 am
by littlebro05
VH_man wrote:this mech is actually very easy to create.... making it compact and air-efficient is the challenge.

Ive done it. It just broke cause i made it out of crappy materials..... lol.

BTW, could you get rid of the All Caps thing? its annoying.
The blowback is whats troubling me, and yet lol air efficient. You'd be better off buying a commercial airsoft blowback than making your own air efficient one in my opinion. I dont' think it would be cheaper to make you're own GBB but making your own NBB is possible.

And yeah take of the caps, it's quite annoying.

Posted: Mon Sep 29, 2008 6:20 am
by Hotwired
i-will have you ever tried to make any kind of gas propelled projectile device without using standard parts for airsoft guns?

If you make the functional basics in a suitable way you won't need a bodyshell because that would just spoil it :)

Normally "guns" need a body simply because they use external mechanisms around the main power source, springs and levers have to be enclosed. The mechanisms of these cannons are always internal because they're mostly valves and an unenclosed valve is a leak.

Of course if you really wanted to make it look like a firearm you could stick a shell on but it has no major function, just there to create the illusion it is a firearm.

Posted: Mon Sep 29, 2008 7:06 am
by Ragnarok
Evidently, this is the thread that's got taken over, so I'll bring my post from the other thread across:
Ragnarok wrote:
ANY QUESTIONS?
As a hint, never ever ask the open question "Any questions?" on this forum, or you'll likely get asked the following questions:
- What is the average flight velocity of an unladen swallow?
- What is the circumference of a moose?
- The cockpit? What is it?

More sensibly, my actual questions are:
- Does everything have to be in CAPITAL LETTERS?
- When did you hear we make homemade weapons? Weapons means something that is used for attacking or injuring people - these are not weapons. Please avoid using the word weapon in future. Gun would be better - but I tend to avoid that as well, using launcher or cannon.
- What on earth makes you think that we can easily build full gas blowback systems on a regular basis? Airsoft guns have accurately machined parts, and most of us don't have the means or money to make such things.
Making a semi-auto is tricky, so most people work on getting lots of power into a single shot - think hundreds or thousands of times the power of your airsoft guns. (This cannon of mine for example is about 400 times the power of a typical 330 fps airsoft gun)

Some of us do try to make semi-auto or even full auto (indeed, it'll be my next project)- but it's costly to do, because we often need to get parts custom made.
Of course, I welcome you to try making these things yourself from store bought parts - you'll find it a lot harder than you think it is.
THE PVC CANNON IS LIKE A GUN WITH NO OUTER BODY.
Most of us work on the function over form mantra - better that it works than it looks great.
I HOPE NO ONE HATES ME FOR SPEAKING MY MIND.
No, but I wish you could have done it with proper grammar and without all capitals.
I WANT TO SHOW U HOW GAS BLOWBACK WORKS.
You might actually be surprised, but this forum has been around for long enough that we know most of these things. I'm not getting at you, but it's usually worth lurking and being modest when you first start here.

Posted: Mon Sep 29, 2008 8:24 am
by Davidvaini
1. Try not to use all caps. Using all caps normally makes you sound like you are aggravated, angry or annoyed. When a person uses it for every single work with multiple paragraphs it simply makes them look mentally handicapped.

2. Don't try to speak down to this forum and its members as a whole. Yes generally there are some idiots on here, but the majority of the members are extremely intelligent.

3. You have a point about how externals need to be improved. However, people on this site have made more efficient guns than a lot of commercially available.

4. You may have not been inspired yet but I highly doubt you have looked at every single page on this site. I still havnt seen every single post on this site.

5. When first starting on a forum, please make sure not to type in caps, bold, different colors, increased or decreased size font, or with incorrect grammar. All of these things will label you as an idiot.

6.Also when first starting out it is best to not express your opinions(if against site) right away. Would you like it if I came to your house for a neighborhood housewarming party and as soon as I get in your house I start bitching about how your glasses and plates don't match?

7. We are not asking for perfect grammar by any means. We are also not asking you to keep your opinions to yourself. We are just saying that when first begining to post on a site, please do so with common kindness.

Re: TRUE BLOWBACK (GBB)

Posted: Mon Sep 29, 2008 8:40 am
by CpTn_lAw
i-will wrote: I KINDA HAVE A HIGH STANDARD WHEN IT COMES TO HOMEMADE WEAPONS. ALL THESE PVC CANNONS AND PEN TUBE STRAPHERS ARE A GREAT WAY TO TEST THEORY BUT THAT IS ALL. GUNS HAVE TWO AREAS TO COVER. THE INTERNALS AND THE BODY. THE PVC CANNON IS LIKE A GUN WITH NO OUTER BODY.

I'd be happy to see what you can show us that covers those two criteria. Btw, i'm an airsoft fanatic too, but spudguning and airsofting are wo separate things. It's like comparing crossbow shooting to 12 gauge sports shooting. Remember, be creative, be safe, and be polite, oh and btw, welcome. :wink:

Posted: Mon Sep 29, 2008 9:33 am
by POLAND_SPUD
well to be honest his capital letters are annoying and from what he said and how he said it one can guess that he has never tried to build anything....

but his diagram shows one thing - that the piston which is being pushed to cycyle the gun has much larger diameter than the barrel...
sure many people before him knew that.. JSR have experimented with blowback guns - AFAIK with no success - but the theory seems sound... and I suppose that a similar mechanism could be implemented easilly into spudguns

Posted: Mon Sep 29, 2008 10:06 am
by CpTn_lAw
it's the same thing that prevents average air rifles to cock back after a diesel-effect shot. Pressure can be bigger on one side, if the area of application is adequately smaller, system will continue its normal course. About that, i'm soon gonna open a new topic on a gun i've been thinking about.

Posted: Mon Sep 29, 2008 10:10 am
by psycix
Ahh so here we have the "licensed to CAPSLOCK", "airsoft weapons god" to tell us how good he is compared to the rest of this forum because he can draw a few nice diagrams.
So far I have seen zero guns from him so I am not sure how "high" his standards are.

This all is just ridiculous.

Posted: Mon Sep 29, 2008 11:00 am
by starman
You rail on the inadequacies of the "improvised projectile projects" :roll: you have found here and then proceed to show diagrams of commercial airgun operation..?.. How about showing us one of your own "improvised projectile projects"? That is generally the mission of these forums after all.

You sound reasonably intelligent. Why don't you come back, take a few minutes to read the forum rules, introduce yourself again and show us one of your own projects.

Oh and, a little humility will go a long way... :wink:

Posted: Mon Sep 29, 2008 12:57 pm
by Antonio
@"I WANT TO SHOW U HOW GAS BLOWBACK WORKS."

I think you need a bit more respect for the ppl on this forum! You are assuming we know nothing, but actually u are so ignorant not to look any deeper. I mean you first of all didnt even make this pics but got ehm of some other site and tried to get the credit"" urself. If you would have made this gun, respect. Otherwise, dont be so cocky. I stand behind Ragnarok's comments.

Posted: Mon Sep 29, 2008 1:25 pm
by Ragnarok
The other members are right - before you criticise our work, where is yours?

If you're comparing us to commercial products, how do you expect teenagers on limited budget could beat vast Japanese toy companies with huge turnovers?

And obviously, you've not been the right section of the site, 'cos Larda's got the drop on them for sheer awesome - OK, it's still not "true blowback" semi-autos...

...it's freakin' plasma cannons and launchers that can shame .50 cal anti-materiel rifles!

Larda is made of win. :D

Posted: Mon Sep 29, 2008 2:00 pm
by jimmy101
THE PVC CANNON IS LIKE A GUN WITH NO OUTER BODY.

Really? So what would you call mortar? A 50cal machine gun? The mortar is nothin but barrel plus a baseplate and bipod. The 50cal is really nothin but framework on the outside. The framework is there mostly to have something to mount the internals on. It ain't there to make it look good.

Besides, comparing something like an airsoft weapon (even if it looks great) to a generic spudgun is apples to oranges. The airsoft is a toy. The spudgun is a lethal weapon.