CDAC

CDAC

Copper Diaphragm Air Cannon

This is the CDAC, or Copper Diaphragm Air Cannon. It isnt called this because it has a copper diaphragm but rather becasue the gun is made mainly of copper pipe and uses a diaphragm valve. Originally I intended to use a piston valve I made on my own, but I was having a lot of problems with it and eventually it broke completly. So I decided to order a diaphragm QEV from McMaster as I had seen on a few other launchers.

In this picture you can see the rear of the gun, where most of the 'action' goes on (Second only to the barrel) In the middle you see the QEV, it has 1/4 in and out ports, and a 3/8 exhaust. It is cast aluminium and ordered directly from McMaster. Since the QEV requires that you fill from the In port, you can see at the top there is my schrader valve. From the schrader you can go down to the blowgun valve, which is the trigger. from the bottom of the QEV is the air chambers. Basically these are just (2) 12" lengths of .75" copper pipe connected together. To the right of the picture is the barrel which comes off the exhaust port.

As of right now I have 2 barrels for the CDAC. One barrel is just shy of 3' and made of .5" copper pipe. This is the main barrel I use and is incredibly accurate as well as powerful. For ammunition, I have made some of my own lead slugs but theyre a pain in the ass and get lost a lot, so I switched over to a more readily avalible yet still awesomely powerful ammunition, AA batteries, which are a PERFECT fit. When you load one, it takes about 3-5 seconds to slide down to the end of the barrel (no breech loader yet, hopefully soon).

The other barrel is simply a .5" long coupling. If you dont know what a long coupling is, imagine taking a .5" pipe coupling ans stretching it out to a length of 12". This barrel is used for shooting special ammunition I make myself.

The ammo is simply a length of .5" pipe, filled with lead. Unfortunately since this barrel is so short, it is horribly innacurate and doesnt bring the ammo up to full speed.

DAMAGE PICTURES!

Since I only resently finished the gun I havent been able to get many damage pictures, but the ones I have are pretty awesome.

CDAC Vs. My old microwave.
This shot was made from approximately 10 ft. away, using a AA battery. The Microwave was lying on its front, so I was shooting thru the top. As you can see it EASILY penetrated the 2 layers of sheet metal on the top, traveled about one foot through the cooking area of the microwave and easily went through the bottom.

Whats more amazing, When I found the battery it was almost completly intact, showing that the velocity was so great that the battery didnt take much damage at all, The battery was reloaded and used in the next shot.

CDAC Vs. OFF! Deep Woods can.
I really enjoyed this shot. I set the can on a brick 20 feet out into my yard, I laid down and 'sniped' it with the AA battery used to shoot the microwave. The can was almost completly de-pressurized before I shot it. Unfortunately the battery was lost after this shot. All I know is that after it went through the can it flew far enough to hit the chail-link fence in the very back of my yard (about 50 feet away from me).

CDAC Vs. Diet Pepsi can.
You can't really tell from the picture but this was an awesome shot! Another 'sniper' job, I got it from about 10 feet back. I hate diet pepsi so much I just couldnt resist! To really appreciate this you need to see the video, it is a GIF animation and it may be somewhat choppy, download it if you need to.

CDAC Vs. My old microwave's door.
This was the first shot I made with the CDAC. I used a small lead slug (.75" long) so shoot right through the door of the old microwave. In case you didnt know a microwave door has about 3 layers of lexan and a 1/8" thick steel mesh. Compared to the next shot this may not be much but hey it was pretty good for a first ever shot. However I do think this next part is pretty funny. The lead slug went right through the door, which was propped up against a tree, it hit the tree and riped off a good deal of bark, pretty deep too.

Other Pictures