Another Air Cannon

In this Instructable I will be describing another design for the all-popular pneumatic (air) cannon. My version is similar to many of the other ones on this site, but my design was my idea so don't say I copied it from you. This is very simple to build, costs little, does not require alot of skill, and is fairly "safe" (especially if you are careful with it).

THE DISCLAIMER:
This is a weapon and can be very hazardous if used irresponsibly or used at all. NEVER, EVER point this at anybody because, despite its benign appearance, It could really mess you up. What you do with this is your responsibility, not mine. It is advisable to check your local laws before building this, it may not be legal where you live. Always treat guns liked they are loaded. Use eye protection. Use common sense. Plastic bottles like the one used in this Instructable can be prone to violent failure which could result in injury. Please take adequate safety precautions and use a PVC air chamber when you intend to use higher air pressures than what has been recommended. Happy shooting!

Step 1: Materials

Materials:

1/2 inch pvc piping (the higher rated, the better)
1x 1/2 inch T connector
1x 1/2 inch ball valve
1x empty 2 liter bottle
Duct or electrical tape
Bike tire valve
Scissors

Comments

[Dr. Explosion]

I finished my sprinkler valve cannon a while ago, here's a picture:

[bylerfamily]

Okay,I finally built this.It is awesome!I will post pics ASAP.

[Dr. Explosion]

Does it work well? I finished working out all the bugs on my sprinkler valve cannon earlier this month, its a mod of this: http://www.instructables.com/id/25MM-Pneumatic-Sniper-Rifle/

[bylerfamily]

Yeah it works quite well.What do you use for ammo in your old an new gun?

[Dr. Explosion]

I usually used grapes for the old gun, for the new one, i modded an empty 12 gauge shotgun shell with collapsible fins and i'm working on giving it an r-candy smoke payload.

[bylerfamily]

As soon as I get a ball valve and a tee I am going to make this...

[Dr. Explosion]

I'd enjoy hearing how it works! Post pictures if you can.

[bylerfamily]

Sure.Only problem is,I am going to be gone for six weeks(I am homeschooled) and I won't get to buy the materials until April.

[tape fist]

I really think that when people make instructables on pneumatic cannons using bottles as air chambers they should include in the disclaimer that that have a tendency to explode.this is a suggestion. other then that and the duct tape its okay for a first : )

[Dr. Explosion]

Will do, thanks!

[bylerfamily]

THIS IS COOL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Dr. Explosion]

Thanks!

[Kindredfool]

how much PSI would a 2 litre bottle take???

[Colonel88]

not much. Also when you said about the non glue part and it will just fly off it will fly off in your shoulder(or near your ear, depends how you hold it.

[Dr. Explosion]

Thats actually a really good point. I've had it shoot off before, but never while holding it. I always press it into my hip which holds it together, but it would be a good idea to glue it. Because you aren't using much pressure to begin with, gluing it won't really allow it to explode, so thats your best bet.

[west49rules]

ive had 125 psi in a pop bottle it worked fine but i would not recomend going over 100 psi

[Dr. Explosion]

That is a very debated topic and I personally do not know, but I myself have never tested one above 30 psi so I haven't been too worried. Some people have said 100+ psi, but I have a hard time believing that.

[milamber]

one of my frends made a similar thing with a 1 litre water botle and usualy charges it to 120 psi

[imkwl12345]

i had a 1.25 litre bottle at about 75psi but our dodgy air compressor couldnt get it any higher

[build a BOOM]

I previously have built a water bottle rocket and accidently, it exploded at 110 psi and I was standing next to it... Louder than a gunshot but no damage or shrapnel at all. (2 Liter bottle)

[LED master22]

unless u are planning on going to the doctor for an injury, please loose the 2 liter bottle, you can't ask for a better way to be cheap and dangerous, invest into a 3-4inch schedule 40 and even 80 pvc.

[Dr. Explosion]

And here it is again

[rocketman217]

i've got 73 psi then it exploded

[ellisgeek]

no you just sead 5 inch under "Pieces:" it ses 5 inch but in the photo it ses 4 inch.

[Dr. Explosion]

heh....my bad...good catch. But it really doesn't matter what size that piece is, as long as it fits in the bottle and still has enough left to attach to the t-connector.

[i wanna do that]

thanks a lot for the instruable...i was thinking of using some copper pipe for the barrel, would that be advisable...i mean if i do make this,this will be my first air cannon so im a noob lol but yh thanks a lot and write back pleases p.s the reason i like this design is that it is so easy to make and most imporantaly it is cheap. i was thinking of using a combustion one but that seemed to risky although i do know a good design for it but yh thanks

[Dr. Explosion]

If you used copper, that would be cool, but not necessary. It would just be a little heavier and expensive. I don't know if it will fit the parts i used, but I know you can buy compatible pieces for copper piping. Have fun!

[i wanna do that]

lol dont worry i will have fun, but if i do make all of it from copper will that make it more powerful as it could proably withstand more air pressure? Also say if just the bareel was copper would that have an effect? write back pls

[Dr. Explosion]

If the barrel was copper, yes it could withstand a LOT more pressure, but using it just for the barrel would be pointless because it does not have much pressure put on it when firing. However, if you built the entire gun, including the chamber, from copper, it could be crazy more powerful, or even better if you used steel piping, but that would cost allot.

[i wanna do that]

ok, thanks a lot, oh yh i have one more question (sorry i know i have been asking you a lot of questions) i cant find plastic ball valves so would a metal ball work with pvc piping? write back pleases

[Kindredfool]

hey i wanna do that. i also live in england and ur best bet for finding ball valves is B&Q under the plumbing and heating section... they are made of metal so just buy some copper pipe (its a little dearer than PVC" but holds loads more pressure! thats how i made mine = )...hope i helped

[i wanna do that]

yeah thanks for the help, its funny cos i went B&Q today and i did see some lever ball valves they had a half inch diameter (did you use those ones?) and what diameter copper piping did you use and (sorry for all the questions) did u make a copper chamber? and did you solder the copper parts together? thanks,write back please

[Kindredfool]

i used a 22mil copper pipe (big enough to shoot marbles cuz i made a marble cannon)and bought a compatible 22mil ball valve..(DO NOT USE THE THE ONES WITH THE CIRCLE VALVE THAT YOU TWIST! I DID THAT AND IT TAKES A LONG TIME TO OPEN AND BY THE TIME IT OPENS THE AIR ESCAPES THROUGH THE SMALLEST GAP>>USE THE LEVER ONE!! lol i just had to but that in caps, the lever one works great because it opens and shuts really fast at a 45 degrees angle. = ) and yes i made all my gun out of copper except my bottle (mineral water..holds 5 litre!) and my pvc mag looking thing... if u make a long copper barrel (the bit with the bottle one) it holds loads more pressure and if u make the shooting chamber half the size of it u will get great results! hope i helped!

[i wanna do that]

wow thanks a lot for the help, ermmm i went B&Q and i could only find 1/2 inch lever vales (did u use those one or were urs specifically 22 mil) also when you connected the copper pipe to the 5 liter bottle did you use the same method of wrapping it in duck tape then inserting the pipe in so it gets a tighter fit? Also did u solder ure coppers pipes together? well once again you have been a big help cos living in england and everything its been good, well write back please

[Kindredfool]

good i helped = ) i will answer all ur questions one by one.
yep my ball valve was exactly 22 mil but you could get a lever valve that compensates...for example 15ml lever,15 mil pipe just look for something that the lever will fit, it will work!
yep i put a smaller pipe (40ml i think)into the neck of the bottle and then taped it on
nope i did not weld the pipes together i just used some tools to get the tightest fit i could get = ).once again i hope i help ya = )

[i wanna do that]

ahhhh you must have used the ball valve with the small lever i went to use the ones with the big lever. Plus are u sure u used a 40 mill pipe to connect to ure bottle i mean that sounds a bit too big, also how did u put in ure bike valve. write back pls

[Kindredfool]

well in the 5 litre mineral water bottles the neck is HUGE! so i used a pipe near enough the same size. also i put my schrader valve in the back of the bottle and dropped it in (cover in glue before do so) i used the extra strong adhesive wich takes 24 hours to dry! lol it sounds like a long time but it really helps.. p.s because u live in england u wilkl probably know a shop called "wilkinsons" and they make theyre own adhesive and its is really strong (by the way im going into it this much because it needs to be tight and strong on the bottle.

[i wanna do that]

yes i do know about wilkinsons, so your pipe to the bottle was 40mil, which im gusseing led to a tee conecter were the other sides were 22 mill? Well with my one im thinking of using a 22mil pipe with a cap end on the air chamber then drill a small hole big enough for the schrader valve and then that pipe leads to a 22 mill lever valve that i can buy from Screwfix then add the shotting barrel and thats it! oh yh by the way did u get ure schrader valve from an old bike wheel or serpreatly from a shop and if so where? cos i can only find schrader valves in the bicycle inner tube that costs like £5 from halfords well thanks alot and write back pls

[Kindredfool]

yeah i bought my innertube and cut it out it was a fiver from wilkinsons = )

[i wanna do that]

ok then