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Double barrel Shot gun design

Posted: Fri Aug 14, 2009 6:57 pm
by queensland spudder
I have being thinking lately of making a double barrel shotgun type combustion.

im wondering should i try to make a single combustion camber firing to barrels or do two separate combustion cambers that will have a lever system that will press both BBQ igniters at the same time .

Im wondering if i do a a single combustion camber system is will need a Y type spit joint to make sure that when the cannon fires it will send two projectiles out of each barrel with same power.
So far i have searched the net for different DWV fittings and the the closet i have found to a Y shaped fitting is a double junction which i don't i will find anywhere in bunnings .

So im thinking just doing a normal junction with a 45 degree bend on the junction to get the barrel back to being parallel ( this will be 100mm), then im thinking of putting adapters from 100 to 40mm.

then i will put two 40mm barrels on each adapter , the only concern is that will this system be able to evenly spread the gases to each barrel cause im not using a 'Y' junction im using a a junction that looks like the letter 'K' but with only one leg ,so the split is not at a equal angle.

it sounds a bit fuzzy, i will try to draw up something to make a clear picture of what im doing.

Posted: Fri Aug 14, 2009 7:09 pm
by inonickname
Use two chambers. If you only use one, as soon as one projectile leaves the barrel then the pressure will drop instantly.

If you want aesthetics and not power, then you could make the barrels the same size as the cartridges.

Posted: Fri Aug 14, 2009 7:15 pm
by theBOOM
Yes like ino said.. having 1 chamber and 2 barrels will also decrease power significantly... on youtube search : girl shooting potato guns or something like that... that what i would recommend but you got tweak the design to make it a double barrel , double chamber shotgun...

Posted: Fri Aug 14, 2009 9:40 pm
by Moonbogg
If you use 2 chambers and 2 barrels, then all its going to be is 2 cannons strapped together. Like has already been mentioned though, using 1 chamber has its issues. So...if it were me, I would use one large chamber and partition it in the middle and even have 2 triggers for each chamber/barrel.

Posted: Fri Aug 14, 2009 11:07 pm
by FORE!!!!
with that design ud think the gasses would follow the path of least resistance,so basically ur botton chamber (the junction before the arm ) would have more power than the junction 45degree top barrel, if that makes sense,basically ur bottom barrel would be more powerfull than ur top barrel

Posted: Fri Aug 14, 2009 11:11 pm
by THUNDERLORD
If you use two of everything, with a link to fire both simultaneously,
The advantage is you can disconnect them into two and loan one to a friend.
My current PVC pneumatic is like that...just haven't built the other half yet.
Got a pressing pneumatic project (more important than my toy for now). 8)

Posted: Fri Aug 14, 2009 11:11 pm
by THUNDERLORD
Ooops...froze up and...this triple. :oops:

Posted: Fri Aug 14, 2009 11:12 pm
by THUNDERLORD
Dang! Triple...my connection is slow and it froze up. :oops:

Posted: Sat Aug 15, 2009 2:07 am
by Pactin
you can use my design if you want:
Image

the only problem I had was fuel injection while still looking and feeling "natural"

Posted: Sat Aug 15, 2009 3:29 am
by queensland spudder
FORE. instead of a juntion i could use a 'T' section and put 90 degree elbows, reducers then barrels, making the path of resistance about the same.

inonickname. i could be interested in aesthetics especially if i wanted to iron sight and stock to get that 'gun' feel. Im not sure how to figure out the pressure problem but i will just try it out and hope for the best.

The boom. i could just make a bigger chamber , cause i will just try to estimate the total lenght of the Chamber then figure out how long each barrel needs to get a good C:B it will be hard cause DWV fittings are curved and are not square but i will figure out a way.

Thunderlord: that sounds like a good idea with the two cannons coming apart , i guess you would have to have two people fill up each cannon with Deo aprox the same amount , put the two together then fire them together.

Or you could have a complex propane fill system that will accurately fill each chamber with the propane, however that would be to complex so i guess the two cannon idea is the easiest and will probably the most successful.

I will try the singe combustion chamber with two barrels only cause i want to try this out and see what would happen, and anyway if you don't try something out then how r u ever going to make progress.