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unreal flak cannon?

Posted: Mon May 19, 2008 2:52 pm
by trollhameran
thinking of making a replica of the unreal 2004 flak cannon,

heres what ive come up with so far

this is the main gun all the grey bits are the chamber, the black is the barrel and the red is the inside of the barrel. So basically the barrel slides forwards and back on 3 runners (the chambers) so that when you slide the barrel forward you can load a shell and you can slide it back to lock the shell in for firing. There will be 2 different shell, primary fire and secondary fire, these will be explained bellow.
Image


Primary fire
The primary fire shell is basically a buckshot of bbs but both ends of the shell will have shrink wrap on them, sounds weird i no but ill explain. At the breach end of the barrel there is a 4 inch sections that is wider than the rest of the barrel, the primary fire shell will fit in this section so that when the gun is fired the shell doesnt launch out but the shrink wrap breaks on both ends and the bbs fire out in a large spread like the flak cannon. then you remove the empty shell by hand and reload.
Image

Secondary fire
The secondary fire shell is longer and narrower than the primary fire shell so that it misses the wider section of the barrel and when the gun is fired the whole shell gets fired out, these will only have shrink wrap on the top, and the bottom will be solid so that the bbs dont get launched out untill impact with the target, like a flak grenade.

Hopefully the shells and the actual gun will have some semblance to the unreal 2004 flak cannon as I have based the look of the gun on a picture of it and the shells are designed to have the same characteristics as the primary and secondary fire of the flak cannon.

Image

I haven't yet worked out what type of valve im going to use but i was thinking either sprinkler or piston, but i think piston may be difficult as i will have 3 chambers on the gun.

Posted: Mon May 19, 2008 3:11 pm
by thewarp16
thats one hell of a thing to make good luck with it.

what are u hoping to fire out of the beast?

im thinking about 20 paint balls at a time ;-)

Posted: Mon May 19, 2008 3:11 pm
by Necrosis
Good luck on the fully automated reloading system... :wink:

Posted: Mon May 19, 2008 3:15 pm
by trollhameran
i will be firing either 100s of bbs at a time or lots of paintballs

i have an idea for an automated system but it needs some thought going into it

Posted: Mon May 19, 2008 4:05 pm
by mega_swordman
A piston will probably be the easiest for what you are doing. This certainly is a nifty idea, one of which I may look into.

Posted: Mon May 19, 2008 4:27 pm
by trollhameran
yeah i was thinking towards using a piston, so i would have a t joint with the piston in and the have the 3 chambers separating off from the main chamber so that i only have to make the piston work for one chamber rather than 3. I have a rough idea how i can make an automated loading system but so far ive only worked out how to make it work for the secondary shells, as the primary shells would need to be taken back out of the barrel once they are empty before a new one can be loaded, whereas the secondary shells will be fired anyway so the next shell could just slide into place.

Posted: Tue May 20, 2008 1:51 pm
by trollhameran
sorry for double post but i need this question answered, does the barrel need to be made of a pressure rated material? as i need to make reducer that will be big enough for what i want

Posted: Tue May 20, 2008 2:31 pm
by brogdenlaxmiddie
Here's my question to you, Will the barrel ever be subject to pressure?

Posted: Tue May 20, 2008 2:46 pm
by trollhameran
Im fairly sure it wouldnt be subjected to much pressure on this cannon as the projectiles will be fairly loose in the barrel. Im more worried about the reducer on the end of the chamber, as i dont think i can get one that will go from a fairly small diameter to a very large diameter, so i was planning on turning one out of wood, the valve will be on the smaller part of the chamber so it wont have any pressure on the reducer when the gun is pressurized before firing, im just worried it will shatter when the gun is fired

Posted: Tue May 20, 2008 9:20 pm
by mega_swordman
trollhameran wrote:sorry for double post but i need this question answered, does the barrel need to be made of a pressure rated material? as i need to make reducer that will be big enough for what i want
Technically no, but I always use pressure rated stuff anyway for safety reasons.

Posted: Wed May 21, 2008 1:24 am
by trollhameran
thanks for answering my question mega_swordman, i will look in to whether i can get a pressure rated reducer the size i need and if i cant then ill just have to make it, i should think as long as the pressure isn't to high, and i use a decent bit of wood, then it wont break as there isn't really going to be any pressure on that part of the gun, except for a small amount as the shell is fired out

Posted: Wed May 21, 2008 6:50 pm
by mega_swordman
Is there any reason why a couplet and reducer won't work? I'm just wondering since I don't think the size of the coupler is much different than the end of a bell reducer.

Posted: Thu May 22, 2008 1:48 am
by trollhameran
Image
Im tryin to make it look as much like the flak cannon as possible, so the chambers are going to be very small diameter pipe compared to the barrel, so i need a reducer that goes from a very small size to a very large size, to go infront of the valve

Posted: Thu May 22, 2008 3:17 am
by Lentamentalisk
hate to say it, but accelerating anything that big to a decent speed with such a short barrel and a chamber with what on a rough estimate looks to be ~1/100 the size of the barrel, is not possible with out high explosives, ie not possible.

Posted: Thu May 22, 2008 5:11 am
by Necrosis
But atleast it will look like teh pwneag.


Seriously. :D