Posted: 07/24/2008 20:42 PM Post subject: CA3 PDAB Airburst Cannon
Major
Joined: 23 Jun 2008 Posts: 395 616.76 Spud Bux
Name: CA3 PDAB (Cannon Assembly Mk. III, Pre-Determined Air-Burst)
Type: Single Shot Pneumatic Cannon, Interchangeable Upper Section
Loading Method: Muzzle Loaded
Barrel Type: 2' by 3" Sch40
Chamber Type: 2' by 2" Sch40 (2x)
Operating Pressure: 30psi-100psi
Fire-Control Sys: FA-E1B NCS
Ammunition: 75mm M2 Shell NAABFW, 75mm 'Skipper' Anti-Materiel
# of Valves: 1
Type of Valves: Stock Orbit Watermaster 1in Sprinkler, Solvent connectors
Sights: None
Projected Improvements: Build additional upper Modules, including Breach Loaders, Small Diameter Barrels, and others.
The CA3 PDAB is a cannon developed under the WC-AB Project to fire specially designed 75mm airburst shells. Designed with ease of reloading in mind, the entire barrel and cable compartment are secured to the valve/chamber assembly via a union. This allows for the use of a number of different barrels and ammunition, but the main feature is its ability to fire a specialized airburst shell, the 75mm M2 Shell NAABFW (Non-Adjustable Air Burst Flour Warhead). Secured to the cable compartment with a large nut, the cable pulls on the shell when it pull tight, triggering it to open. Its secondary armament, the 75mm 'Skipper' Anti-Materiel round, is nothing more than a long water bottle filled with water. Launched at 90psi, it travels about 50' before hitting the ground and skipping, maintaing sufficient kinetic energy to knock over sandbags, useful for taking out unmanned fortifications. It uses an upgraded variant of the FA-E1 NCS, the FA-E1B. The 'B' model makes up for the shortcomings of the initial model, adding a second battery and a SP-ST safety.
EDIT July 27: Sorry for the confusion about the pictures, everyone. I did indeed take the pictures when I said I did, I just became unexpectedly busy in the last two days. Sorry about any confusion.
Test shot with the CA3 prior to the completion of the airburst shells.
thats pretty cool i had an idea where an model (rock-it) engine (SHHHH)
was launched and the cone and parachute was filled with bbs and when the ejection charge popped out the cone, bbs would rain down on the enemy. pretty effective if there was now wind.but it was kinda like a portable air strike cause i launched it out of a pvc pipe.
EDIT: i know im not supposed to talk about things that burn but i had to say it cause it is so cool.siiiiiiiiiiiiiiiigggggggggggghhhhh, well im sorry jeez.
Nice post.
A barrel support would definately be a good idea.
The recoil puts stress on the connections ( The barrel flex can be seen in the vid).
I wouldn't want to use it without a barrel support.
Or with the bell reducer (already mentioned).
Other than that looks like a nice test platform for various stuff.
BTW, you could also mount it on wheels inside the doghouse in vid, paint the doghouse blue and white and change the name to c3p0 instead of CA3 PDAB
EDIT: OoOps, I got r2d2 and c3po confused. Maybe it could be a cross between the two and the name could stay CA3 PDAB, Cool! (JK)
I agree with you that the bell reducer in this application will be under much less stress...but...
You are using your sprinkler valve as the sole structural support between the chambers and barrel. The design also makes any proper barrel support fairly large, but something you should add on there soon to take the stress off of your 1 1/4" feeder and sprinker.
It's little gangly looking but you're generally getting the job done there. When do you plan to shoot a real airburst?
Good job with the detailed post!
Last edited by starman on 07/27/2008 12:01 PM; edited 1 time in total
Nice, and interesting design, im curious though, do you have canaries? I can hear them in the background pretty well.
Back on topic, i would have chosen a different design, only because of the stress on the valve and the fittings, but its ok and looks fun and portable.
Yeah, I know. Bell reducer DWV blah blah blah, doesn't really matter in this cannon. Yes, support would be nice. I MAY build some. And I MAY actually have to put it in the doghouse. That just sounds fun. BTW, this crazy piece of crap takes forever to fill off of my 3gal compressor. God, it's like 10 minutes between shots. Besides that, I'm fairly pleased with it. Also, I am happy that the line I will be using is rated for 370 pounds of force.
BTW, I may take a break from new crazy ideas (*cough*autocannon*cough*) and just build a simple, easy to design, QUICK TO FILL, airsoft cannon or mortars by the buttload or something.
... And I MAY actually have to put it in the doghouse. That just sounds fun...
It was kind of a dumb joke.
Although an RC battlebot with cannon would be pretty cool IMO! (But dangerous) And that would make a sturdy shell for one.
The way your valve is configured is how I wanted to attach one to test recoiless concepts. (By adding other barrel on the back to fire and test some sort of countershot).
Also, I was thinking of attaching several valves and chambers (vertically) to one barrel to build a "Metalstorm" concept pneumatic. (But designing a good one way valve for each valve is not my idea of fun right now).
BTW, sounds like you'll be building a new one soon? ( )
Bell reducer DWV blah blah blah, doesn't really matter in this cannon
Sorry I just have to quote you on that
dwv is not blah blah blah, it is serious. All your cannons are an extreme danger to operate and I wouldnt want to be anywhere near it when you were charging one up or firing.
I know that it is under pressure for only a short amount of time but that doesnt mean it wont go boom or fly off, esspecially with the heavy ammo you are using. But in your other cannon the dwv is under a constant pressure which is VERY dangerous.
You assume that it is fine because it hasnt gone boom on you yet, but its only a matter of time before it does.
C'mon, give the guy a break. If you actually took the time to notice that the bell reducer is on the BARREL, then you'd know that it's not important. Okay, so if hey uses some ungodly high pressure in the cannon, (which he doesn't) then his barrel might blow off. OH NO! (Big deal, I know) Before you guys jump on him for using DWV, you could at least give him props on what a nice launcher he built. [/rant]
Anywho...
Nice job man. You seem to be a very promising upcoming member and i hope to see more from you in the future. But as bigbob was saying, just be careful not to use any non-pressure rated parts on your future chambers. For barrels, DWV=OK.
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