I just came up with these plans for my 1st pneumatic cannon. I dont know if its a good idea because it might be too heavy, and that the chamber(4'')is much bigger than the barrel(1 1/2'').Will thes work good?
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Will this work?
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- Spudshot, this is the only kind of reducer that I can find in my area, The home depot lady said id have to order it online if i wanted 4'' to 1 1/2'', or she could make one for me...since I was too excited, I had her make this for my combustion.
The insid - reducer.jpg (10.17 KiB) Viewed 3852 times
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Last edited by nabu92 on Sun Feb 12, 2006 7:02 pm, edited 1 time in total.
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cardinals08
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well, it should work, you would get better performance if you made the barrel longer
or if you wanted the barrel that short, you could shorten the chamber alot
or if you wanted the barrel that short, you could shorten the chamber alot
http://ultimatehobbies.7.forumer.com/in ... c6aff553ef
my site, nothing on it yet
my site, nothing on it yet
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cardinals08
- Specialist 2
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- Joined: Thu Dec 22, 2005 5:07 pm
well, you could probably go almost double the length of what you have posted
http://ultimatehobbies.7.forumer.com/in ... c6aff553ef
my site, nothing on it yet
my site, nothing on it yet
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Brian the brain
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Also I think it's better to place the valve at the very beginning of your barrel.Not at the end of your reservoir.Think about it.THe way you've drawn it the air can expand after it "leaves" the valve through the bend before it hits the projectile.Loss in performace if you ask me.
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drac
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Absolutely correct. Dead space minimizes performance.Brian the brain wrote:Also I think it's better to place the valve at the very beginning of your barrel.Not at the end of your reservoir.Think about it.THe way you've drawn it the air can expand after it "leaves" the valve through the bend before it hits the projectile.Loss in performace if you ask me.
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boilingleadbath
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Eh, dead space reduces preformance, but is the loss of preformance by the barrel space the sprinkler takes up more noticeable?
This sounds like a job for the GGDT! <insert searchlight-projected picture on cloud here>
Both guns being modeled Use a 50g projectile in a 1.59" bore, with the sprinkler valve data provided by the GGDT site.
The valve-on-bottom design assumes deadspace is 26 cubic inches, and uses a barrel length of 49". Muzzle velocity at 100 PSI is 354 fps, at 50 psi it's 278 fps.
The valve-on-top design assumes deadspace is 3 cubic inches, and subtracts 5 inches from the barrel length (uses 44" barrel) to account for the length of the valve. Muzzle velocity at 100 PSI is 329 fps, at 50 psi it's 255 fps.
...so yeah, putting the valve on the bottom is your best bet. That being said, you could use a 24" chamber (lighter, easier to fill) and only lose about 3 feet/sec.
This sounds like a job for the GGDT! <insert searchlight-projected picture on cloud here>
Both guns being modeled Use a 50g projectile in a 1.59" bore, with the sprinkler valve data provided by the GGDT site.
The valve-on-bottom design assumes deadspace is 26 cubic inches, and uses a barrel length of 49". Muzzle velocity at 100 PSI is 354 fps, at 50 psi it's 278 fps.
The valve-on-top design assumes deadspace is 3 cubic inches, and subtracts 5 inches from the barrel length (uses 44" barrel) to account for the length of the valve. Muzzle velocity at 100 PSI is 329 fps, at 50 psi it's 255 fps.
...so yeah, putting the valve on the bottom is your best bet. That being said, you could use a 24" chamber (lighter, easier to fill) and only lose about 3 feet/sec.
thanks, that helps 
. I just found only have 30'' of 4'' pipe left, so I couldnt make the chamber as big as I planned. And 24'' would make it lighter too. ............I still need to know if the reducer that I have is ok to use on this cannon.
. I just found only have 30'' of 4'' pipe left, so I couldnt make the chamber as big as I planned. And 24'' would make it lighter too. ............I still need to know if the reducer that I have is ok to use on this cannon.