GGDT shows my Projectile never cleared muzzle but it actually went 40 yards. I know I'm just entering something wrong. Does anyone know what it is? I have attached a capture of GGDT.
My gun consists of:
Chamber is 4" sch 40 by 12 " long, pressured to 80 psi => inline 1" sprinkler valve actuated by a momentary switch => Barrel is 4" sch 40 by 16" long => projectile is 3" wide by 10" long, 1 pound, with a rag stuffed in the barrel for a packing wad.
GGDT -Proje never cleared muzzle but actually went 40 yards
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MrCrowley
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Why do you have a 4" barrel with a 4" chamber? 
You've got more volume in the barrel then chamber and with such a large bore im not suprised it only went 40yards,infact i am suprsied it went 40yards. Its because of the wadding that it went that far without it the projectile wouldn't clear the barrel.
You've got more volume in the barrel then chamber and with such a large bore im not suprised it only went 40yards,infact i am suprsied it went 40yards. Its because of the wadding that it went that far without it the projectile wouldn't clear the barrel.-
clide
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Your dwell time is set to 0 which means the valve closes immediately after opening. Set it to something high like 1000.
You probably shouldn't be using generic anyway since GGDT has settings to model pilot valves.
You probably shouldn't be using generic anyway since GGDT has settings to model pilot valves.
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jackssmirkingrevenge
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your dwell time's 0 
edit: hadn't seen clide's post
edit: hadn't seen clide's post
hectmarr wrote:You have to make many weapons, because this field is long and short life
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frankrede
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I fiund it hard to believe that your cannon made that distance.
I have one with a similiar setup except I have a 3" barrel.
Adn even with a pefect airtight sabot I could barrely get 10 ft
I have one with a similiar setup except I have a 3" barrel.
Adn even with a pefect airtight sabot I could barrely get 10 ft
Current project: Afghanistan deployment
Thanks! That was the problem.
Clyde, I don't see an option for pilot valves. I have the following options: Chamber Seal, Barrel Seal, Burst Disc, Hammer and Generic in version 4.4. What version are you using?
frankrede, the projectile goes 40 yards with a t-shirt stuffed tightly in the bottom. GGDT shows a greater distance but I'm probably not holding the gun at a 45 degrees angle.
Clyde, I don't see an option for pilot valves. I have the following options: Chamber Seal, Barrel Seal, Burst Disc, Hammer and Generic in version 4.4. What version are you using?
frankrede, the projectile goes 40 yards with a t-shirt stuffed tightly in the bottom. GGDT shows a greater distance but I'm probably not holding the gun at a 45 degrees angle.
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super spuder
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sorry, but could someone send me a link on where to download GDT.
trying to decide on a new project, probably something small.
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pyromaniac
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I found it with a search:
Valve type: Barrel sealing
Piston seat diameter: 1.2"
Piston diameter: 2"
Piston mass: .8oz
Flow efficiency: 23%
Pilot volume: 1.1 in3
Dead volume: 2.2 in3
Vent Diameter: .1" (.2" if you modded your blowgun)
The guy that wrote this is a genius! GGDT says my projectile will go 41.33 yards and it went 40 yards according to my range finder.
Valve type: Barrel sealing
Piston seat diameter: 1.2"
Piston diameter: 2"
Piston mass: .8oz
Flow efficiency: 23%
Pilot volume: 1.1 in3
Dead volume: 2.2 in3
Vent Diameter: .1" (.2" if you modded your blowgun)
The guy that wrote this is a genius! GGDT says my projectile will go 41.33 yards and it went 40 yards according to my range finder.