Introduction: How to Make a Air Cylinder (cheap) for an Air Gun.

Picture of How to Make a Air Cylinder (cheap) for an Air Gun.

I've been searching for a cylinder for an air gun but they are very expensive. So I thought of how a bike works. The inner tube has a valve that allows air to be passed into and passed out of when pressure is applied. Using a inner tube is out of the question to be used as an air cylinder.
Inner tube has a great concept but the soft rubber can stretch and pop under alot of pressure. I found that you can use a metal bottle...
I'll explain it all in the tutorial.

(Note; I wont use real pictures just drawings to explain each step because of copyrighting)

Step 1: The Things You Will Need!

Picture of The Things You Will Need!

It is important that you have the right items for this. Here is a list;
1. A metal bottle (preferably air tight and has a metal lid)
2. Tyre valve (car tyre valve)
3. Pumper with Pressure metre

The tools you will need are;
1. A drill
2. Drill bit set
3. UniBond all purpose sealant (extra security)

Try getting the bottle from Halfords. It's like around £5. The Tyre valves you can buy online for around £5. Four come in each pack) from sourcingmap.com. You can get a pumper from a car/ bike shop. and the unibond from a DIY store.

Step 2: Drill a Hole in the Bottle Lid

Picture of Drill a Hole in the Bottle Lid

Use a drill bit that is the same size as the Tyre valve. (make it a clean straight drill through)

Step 3: Plug in the Tyre Valve

Picture of Plug in the Tyre Valve

When you plug in your tyre valve there should be two layers of rubber with a space in-between. Try to put one side of the rubber through the lid hole so it stops any air from leaking through the gaps. If air does leak use the Unibond to seal all the holes and leave to dry for 24 hours

Step 4: Finished Cylinder

Picture of Finished Cylinder

Now just screw back on the lid (feel free to put some UniBond on the thread of the lid if you haven't got a sealed bottle)... It would be best if you find a unwanted lid that has a rubber seal and drill a whole that matches the valve hole.

Then fill with air using a pressure gauged pump. The air will start to get compressed in the cylinder. Because of how rigid aluminium is compared to rubber, it will not pop under extreme pressure.
If you are still worried you can just make a case for it to keep it secure.

Step 5: Finished

Your Air cylinder should be filled with compressed air now. You can attach a bike pump adaptor to a blowgun and shoot pellets and BB's.

(Working on a Video Demo.)

Comments

Mike63 (author)2015-01-21

I have done something similar with 1 liter plastic bottles, but I have only tested up to 45PSI. I didn't have bicycle tire air supply in mind but thought I'd share. The reason for so many holes in the manifold I was practicing using a tap I bought to match the threads on the tire valves.

ilpug (author)2012-06-06

I am not sure about how pressure-safe this is... you might want to ask the community at large what the pressure rating of thin wall rolled aluminum is.

Rimwulf (author)ilpug2012-12-11

prolly put steel bands or such to reinforce the bottle perhaps brick strap?

ilpug (author)Rimwulf2012-12-11

no, won't work, it will still be weak. Use an old fire extinguisher

Rimwulf (author)ilpug2012-12-13

How about using an old spray can?

ilpug (author)Rimwulf2012-12-13

Well, it's possible, but has two issues:

1. Those are only tested to 80PSI
2. They have very thin walls, so it's hard to thread fittings onto them with safe airtight seals, you would need epoxy.

Rimwulf (author)ilpug2012-12-13

I saw some converts where they took a aluminium bottle and filled with pressurized content and it (not the beer Cans but beer bottles out of aluminium an can withhold up to 80 psi and the walls of the bottle are really sturdy.

suggestions

ilpug (author)Rimwulf2012-12-13

I wouldn't use them. Metal has a habit of just blowing up with no indicators. They might have put it up to 80, but it might burst at 81. Just go get metal and make a real threaded air cylinder, it's the simplest and safest way to do it. Using makeshift cannisters is simply not how to do it, and your better off not working with pressure.

qboid (author)ilpug2012-12-12

It's been tested at 200psi. I wouldn't go above 300psi though. I have a dent in one of my bottles and 200psi is not enough to punch out the dent.
I highly recommend NOT to use an airgun pump or carbon fibre tank to fill this.

qboid (author)2012-12-11

Well I did use a car cigarette air compressor to fill to 200psi on my new project which I will upload soon.
PS. The bottle I used on my new project has a dent in it and 200psi is not enough to punch out the dent.

Rimwulf (author)2012-12-11

What about an aluminium bear bottle?
http://www.hoppsy.com/youtube/the-aluminum-bottle-can/

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