unreal flak cannon?

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
User avatar
trollhameran
Corporal
Corporal
Posts: 515
Joined: Tue Dec 04, 2007 5:41 pm

Mon May 19, 2008 2:52 pm

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.
thewarp16
Private 4
Private 4
Posts: 81
Joined: Tue Jan 08, 2008 3:00 pm

Mon May 19, 2008 3:11 pm

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 ;-)
User avatar
Necrosis
Specialist 2
Specialist 2
Posts: 239
Joined: Tue Jul 03, 2007 10:03 am

Mon May 19, 2008 3:11 pm

Good luck on the fully automated reloading system... :wink:
Allthough we may be the most intelligent creature on this planet, we are also the most inconsistent.
To find peace within our existence we often create a logic that endangers our lives.
User avatar
trollhameran
Corporal
Corporal
Posts: 515
Joined: Tue Dec 04, 2007 5:41 pm

Mon May 19, 2008 3:15 pm

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
User avatar
mega_swordman
Corporal
Corporal
Posts: 526
Joined: Wed Nov 29, 2006 2:37 pm
Location: Bay Area, California
Contact:

Mon May 19, 2008 4:05 pm

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.
"Never tell people how to do things. Tell them what to do and they will surprise you with their ingenuity." George S. Patton
User avatar
trollhameran
Corporal
Corporal
Posts: 515
Joined: Tue Dec 04, 2007 5:41 pm

Mon May 19, 2008 4:27 pm

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.
User avatar
trollhameran
Corporal
Corporal
Posts: 515
Joined: Tue Dec 04, 2007 5:41 pm

Tue May 20, 2008 1:51 pm

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
brogdenlaxmiddie
Corporal
Corporal
Posts: 562
Joined: Sun Jul 22, 2007 2:19 pm

Tue May 20, 2008 2:31 pm

Here's my question to you, Will the barrel ever be subject to pressure?
User avatar
trollhameran
Corporal
Corporal
Posts: 515
Joined: Tue Dec 04, 2007 5:41 pm

Tue May 20, 2008 2:46 pm

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
User avatar
mega_swordman
Corporal
Corporal
Posts: 526
Joined: Wed Nov 29, 2006 2:37 pm
Location: Bay Area, California
Contact:

Tue May 20, 2008 9:20 pm

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.
"Never tell people how to do things. Tell them what to do and they will surprise you with their ingenuity." George S. Patton
User avatar
trollhameran
Corporal
Corporal
Posts: 515
Joined: Tue Dec 04, 2007 5:41 pm

Wed May 21, 2008 1:24 am

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
User avatar
mega_swordman
Corporal
Corporal
Posts: 526
Joined: Wed Nov 29, 2006 2:37 pm
Location: Bay Area, California
Contact:

Wed May 21, 2008 6:50 pm

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.
"Never tell people how to do things. Tell them what to do and they will surprise you with their ingenuity." George S. Patton
User avatar
trollhameran
Corporal
Corporal
Posts: 515
Joined: Tue Dec 04, 2007 5:41 pm

Thu May 22, 2008 1:48 am

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
User avatar
Lentamentalisk
Sergeant 3
Sergeant 3
Posts: 1202
Joined: Tue Aug 07, 2007 5:27 pm
Location: Berkeley C.A.

Thu May 22, 2008 3:17 am

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.
Do not look back, and grieve over the past, for it is gone;
Do not be troubled about the future, for it has not yet come;
Live life in the present, and make it so beautiful that it will be worth remembering.
User avatar
Necrosis
Specialist 2
Specialist 2
Posts: 239
Joined: Tue Jul 03, 2007 10:03 am

Thu May 22, 2008 5:11 am

But atleast it will look like teh pwneag.


Seriously. :D
Allthough we may be the most intelligent creature on this planet, we are also the most inconsistent.
To find peace within our existence we often create a logic that endangers our lives.
Post Reply