Wanting to make a compact full-sized pnuematic coaxial.
I don't really think that ALL of this data is necessary to answer my basic question, (What is the optimum barrel length for a 1/2" pvc barrel, in a ~18 inch length 2" pvc coaxial chamber.), but I'll do my best to fill in the data requested.
Reservoir:
Gas = Oxygen obviously.
Temperature = ~65 F
Pressure = ~130 lbs
Outer Diameter = 2" (ID of pipe.)
Inner Diameter = 3/4" (OD of barrel)
Length = ~18"
Volume = ??? Isn't that one of the things we are trying to determine here ?
Valve:
Type = ??? What do you call a valve that seals against the end of the barrel in a coaxial ?
Flow Coefficient = ??? Beats the heck outta me !
(In other words, I am the manufacturer, and for the life of me, I can't get myself to write up some literature with that answer in it. My customer service is obviously not the best in the biz. I think I'm going to have to subtract a star or three when I go to rating my experience with me, as the manufacturer.)
Seat Diameter = Ok, I can kinda answer that one. It will be a one inch valve, riding inside a 1-1/4" pipe, sealing up against the end of a 1/2" barrel.
Open/Close Time = Purty durn quick. IOW: As fast as I can make it do so. LOL
Dwell Time = Forever. IOW: it opens and dumps the contents of the res. Then it stays open forever. Until, of course, I fill it again, which closes the valve again.
Dead Volume = I have no idea what that means. I don't think this thing will bring down a zombie, if that's what you mean.
Piston Diameter = Easy enough. 1-1/4"
Piston Mass = It ain't catholic, so I don't think it's going to be going to mass. As for the overal weight and volume... I have no idea. I haven't made it yet. I'm waiting for this request to be answered, before I even start.
Vent Diameter = Big. Going to be eixiting via a 1-1/4" pipe, and sprinkler valve. I'll make the volume behind the piston as small as possible. I don't want JSR to be stomping in my cheerios about wasted volume. LOL Bottom line, I'll be aiming for dumping the volume behind the piston almost instantly.
Pilot Volume = Like I said as small as possible.
Hamr Force = enough to give you a bruise if you are foolish put some part of your anatomy in front of it.
Hamr Dist = Actually, this isn't even a hammer valve, is it ? Ok, never mind these last three. LOL
Hamr Mass = See last answer.
Barrel:
Bore = 5/8" (Hey, I never knew 1/2" pvc pipe was actually 5/8" inside diameter !)
Length = ??? This is the question I want answered. What's the optimum length barrel, for a coaxial with an 18" x 2" chamber ???
Projectile:
Friction = Almost no pressure at all, to get it started moving. (Works REALLY well, just as a simple blowgun.)
Mass = Ok, ok, I'll consider trying to get my projectiles to convert to catholisism. I don't know why you guys are so hung up on going to church ! Meanwhile, they weigh maybe 1 to 3 ounces at the very most ??? A drywall screw and little plastic caplike thingy.
Diameter = Almost EXACTLY the same as the bore of the barrel. So, 5/8".
Init Position = snugged in against the piston surface once the piston is closed against the barrel.
Compute Performance
When you've got all your input data to your satisfaction, push this button and GGDT will do it's thing! Be patient though. GGDT takes a fair amount of CPU cycles. It may take a few seconds for it to return with it's answer.
If this takes more than a few seconds, I want my money back !
Thank you very much, in advance.