20 replies to this topic

[Ironman]

I have been thinking of a new homemade to use my bolt action idea(s) but cannot decide on a good airtank that will deliver the performance of more then 5 shots but not the bulkyness of the my previous air-tank on my other nerf gun. If any of you guys/girls could give me a pic., instructions, or a link, that would be great.
Thanks.

[notorious oxide]

2 litre bottle
1.25 litre bottle
i have tested both and they can hold over 180 PSI
you would just have to reinforce the lid though

[Ironman]

One: How do you reinforce the lid?
Two: How did you test the bottles?
Three:How come the threads didn't give way to the pressure?
Four and the final question is... I heard good things about CO2, is that another good route?

[Jlego]

2 litre bottle
1.25 litre bottle
i have tested both and they can hold over 180 PSI
you would just have to reinforce the lid though

Sorry, don't mean to flame in any way, but my bullshit meter just jumped the scale.
I did an analysis of how much a 2 liter could hold last year when I helped my physics teacher with the bottle rocket launcher he made. The most we ever got a bottle to hold was 140 PSI, and that was with some special tape he had making the sides slightly stronger. either way, when a bottle passed the 130 psi mark, it usally split and made quite a "pop". Yeah. quite a pop.
Either way, if your PSI readings aren't made up or total bs, I'd like to know what bottles you're using and where I can get some.
-Jlego

[notorious oxide]

a friend of mine told me that.
im sorry of its wrong.

Edited by notorious_oxide, 22 March 2005 - 06:12 AM.

[Ironman]

Well, is there any other type of Air-tank that is comcast and holds a fair amount of P.S.I.?

[Tinkerer]

Well, is there any other type of Air-tank that is comcast and holds a fair amount of P.S.I.?

I don't know what you mean by "comcast", but at a camping store I saw 20oz camping fuel tanks that might make fair air tanks. If you know how, you can nest a 2 liter bottle inside a 3 liter and fill the gap with epoxy. That'll hold plenty of pressure.

[Ironman]

I meant to say compact but I might go with CO2 unless the soda bottle idea works... What do you mean by nesting a 2 liter inside a 3 liter?

[Pineapple]

2 litre bottle
1.25 litre bottle
i have tested both and they can hold over 180 PSI
you would just have to reinforce the lid though

Then you say that a friend told you that?

Please remember that the misinformation you post could get someone hurt if they take your word for it....sure it's caveat emptor , of sorts, but it really does make sense to carefully research what you are hearing before you post.

Ideally, if you're going to post things like this, it'd be better if you posted what you have experienced yourself in your own R & D work. Telling someone to do something you haven't even tried is risky at best, dangerous at worst.

Ironman, you know by your homemade how much pressure your "back-pack" tank can take. Is it more pressure, or more volume that you need? What kind of application do you have in mind? Sounds like you're going to try something like Boltsniper's CO2 rifle?

Since you already know the pressure thresholds of PVC pipe, why not work on a more linear design that could be incorporated into your homemade's layout? Granted, it'll have to be made of 2-3" PVC, but for your multi shot application, that sounds like the most reasonable route and still keep it "Nerf".

Personally, I am begining to try my shot at a bottle supplemented shooter based on an AT2000. At the same time, I will be finding out the operating pressure of an AT-type blaster by running a miniature pressure gauge in the line (I have to make use of these little gadgets I find). Once I find out the approx. operating pressure, I'm going to figure in how much we can pump up the (1-liter) clear PET bottle, acting as a supplemental air tank. I'm figuring to try to accomplish this with techniques and materials that anyone can obtain, so that it could be duplicated. Will it work? Hell, that's what I'm going to find out.

Good luck with your continued research. Onward!


-Piney-

[Ironman]

By volume, you mean the amount of air in the tank correct?
I am looking for both amount of air and pressure. I need an airtank that will give me atleast 5-10 shots and be compact. My back-pack on my previous gun was big, blucky, and heavy. Any ideas, Piney?

[Tinkerer]

I meant to say compact but I might go with CO2 unless the soda bottle idea works... What do you mean by nesting a 2 liter inside a 3 liter?

you first, superglue, three spacers about 5/8" (prefferably made of metal) onto the bottom of a two-liter bottle with the lable removed.

Next, you take a brass fitting that will screw onto the bottleneck, and will extend well above the rim of a three liter bottle, and plumber's goop it on.

After that, cut a 3 liter bottle's top off, right above where the label used to be.

Following, place the 2-liter bottle inside the bottom of the three liter bottle.

Next, fill the gap between the two bottles with epoxy resin.

before the epoxy really starts to set, (you should use the stuff that takes 12 hours to harden) duct tape the top part back on the 3-liter bottle.

Next, fill that gap with more epoxy, until it's exactly to the brim of the three liter bottle.

Finally, drill a hole in the three-liter bottle's cap that lets it fit over the brass fitting, screw it on, seal it, and let the shtuff set for a couple days.

There you have it, a very neato, relatively high-pressure tank.

I personally haven't tried this because I can't afford that much epoxy, (1 liter )

Edited by Tinkerer, 25 March 2005 - 03:07 PM.

[Pineapple]

Woah.

One liter of epoxy is going to make a pretty heavy airtank. But I like the creativity of it.

I just thought of the PET bottles' ability to expand a little, and the 1 liter "tank" flexibility to afford some extra volume. Enough for multiple shots, hopefully.

Again, I'm going to wait until I get my hands on a 2k, and find it's operating pressure before making any conclusive moves from just brainstorming. I'm going to attempt to mate the PET threads to PVC fittings, so PVC could be used as the air plumbing.

Oh, just FYI, my brother-in-law made some pretty neat rockets using 1 and 2 liter soda bottles filled with water and compressed air, and they have pumped them up to 110 psi before he freaked out and decompressed it (exploded it) with a shot from a .177 pellet gun (which was pretty cool to see also.) Most of the impressive launches (up to 100') were with 80-90 psi before the launcher released them.


-Piney-

[Ironman]

I was thinking of using 2'' PVC right behind the valve. About 7 or 8 inches? Do you guys think it will work?

Edited by Ironman, 27 March 2005 - 08:11 PM.

[Greek Assassin]

Maybe you could use 1 1/4 pvc and endcaps to make an airtank.

Edited by Greek Assassin, 01 April 2005 - 02:05 PM.

[Ironman]

Yeah, I am going to experiment. The two soda bottles idea is going to be 'yea' heavey.

[Greek Assassin]

I'm also working on a bolt-action air rifle, and I have a question. First of all, would the valve thingy in the rapid fire 20 release air fast enough to fire a powerfull shot, and if not, what type of valve would?

[GeneralPrimevil]

I would recommend strongly against the RF20 valve; To small of an opening. Try for a half inch valve of some sorts, even if you have to make one in metal shop.

Just a thought here, but what about regged HPA? The prices may be slightly prohibitive however. It all depends on how badly you want multiple powerful shots.

[Ironman]

What is HPA?

[boltsniper]

What is HPA?

High Pressure Air

Paintball tanks...

[Greek Assassin]

I found a much better air system for my rifle. I'm not sure if this has been done before, but i hooked up a titan airtank to an rf20 bladder with the rf20 valve in between. After every shot you have to press the button on the valve and the bladder fills up the air tank. This should hopefully keep the air pressure more consistant.

[Ironman]

I don't have either guns though...