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Barrel lengths Questions

Posted: Thu Jul 28, 2011 10:31 pm
by jsefcik
I have an air cannon with mutiple barrels that i want to make how long should the following barrels be( my air chamber is 14 inches)

1/2 inch copper pipe
1/2 inch pvc sch40
1 inch pvc sch 40
3/4 pvc sch40
1 1/2 pvc sdr 21

Posted: Thu Jul 28, 2011 10:33 pm
by Gun Freak
Longer the barrel, better velocity. Just don't make it rediculously long like 20 feet lol

Posted: Thu Jul 28, 2011 10:35 pm
by jsefcik
Would 4-5 feet be good?

but for my golf ball barrel i have 36 inches, which works great

Posted: Thu Jul 28, 2011 10:41 pm
by Gun Freak
Yeah play around with ggdt

Posted: Thu Jul 28, 2011 10:50 pm
by jsefcik
Gun Freak wrote:Yeah play around with ggdt
wont work on my computer

Posted: Thu Jul 28, 2011 10:51 pm
by Technician1002
The optimum barrel length will vary. Items such as projectile weight, valve size, chamber size, and pressure will all need considered in finding the best barrel length for your launcher.

As mentioned in the above thread, install GGDT and work with the numbers.

It is possible to have a barrel too long so the projectile will slow down before reaching the muzzle. Long barrels are best supported by larger chamber volumes and high flow valves. Smaller chambers, and high pressure support shorter barrels. Large low pressure chambers with a high flow valve work best with longer barrels.

Posted: Thu Jul 28, 2011 10:57 pm
by Mr.Tallahassee
wont work on my computer
I think he has a Mac. GGDT won't work on a Mac.

Posted: Thu Jul 28, 2011 11:17 pm
by jsefcik
I have a toshiba, i tried downloading it, all it does is extract the files about 20 times and nothing happens, wish it did work

Posted: Thu Jul 28, 2011 11:25 pm
by MrCrowley
Have you tried running it as administrator (right click on the .exe, click 'run as administrator')?

Posted: Fri Jul 29, 2011 12:03 am
by jsefcik
MrCrowley wrote:Have you tried running it as administrator (right click on the .exe, click 'run as administrator')?
What ?

All i see is languages, COMDLG32,COMDLG32.OCX, example gdt,ggdt4.6,MSCHRT20,MSCHRT20OCX, that is all i get when i open the file and if i click anything it says extract files and just gives me what the beginning file says idk what to do

Posted: Fri Jul 29, 2011 12:08 am
by Mr.Tallahassee
Try to run it without extracting. I did that to make sure it was a successful download. Open "ggdt4.6". It should be an .exe file.

Posted: Fri Jul 29, 2011 12:13 am
by jsefcik
Ohh ok i found how to run as adminstator, My mom isnt awake for the passwords ill have to try tomorrow when she is awake

Once i open it will i get what i see on the website?

Thanks guys=)

No one answered my questions though

Posted: Fri Jul 29, 2011 12:21 am
by jackssmirkingrevenge
:D

Posted: Fri Jul 29, 2011 1:21 am
by Crna Legija
jsefcik wrote:I have a toshiba, i tried downloading it, all it does is extract the files about 20 times and nothing happens, wish it did work

O RLY (pic incoming)

edit:

Posted: Fri Jul 29, 2011 9:46 pm
by jsefcik
That ggdt thing is so dam complicated