Cannon test tools.

[jrrdw]

Here's the basic idea. Something attached to the muzzle with a pressure gauge. This could test the end results of the flow leaving the cannon. That would take the guess work out of it.

Yes, i'm a tool guy, bought or home made.

[carter]

well i don't really understand the point. all you would be testing is the pressure which could be worked out by hand. if you felt like it. whats the main reason you need to no it?

[jrrdw]

To determine best performance set up. getting the most out of your launcher. How has it been proved that 1/4" opening is max flow? Members with crony's can only measure the speed/fps of the projectile being launched. Can the crony's take in account the differences of the projectiles? When launching home made ammo, how consistent is each individual projectile?

Thats why I'm thinking, test the flow it's self at the muzzle.

[jackssmirkingrevenge]

How has it been proved that 1/4" opening is max flow?

mathematically

[benstern]

You would need a really fast camera to capture the correct results.

[jrrdw]

You would need a really fast camera to capture the correct results.

I was thinking a steel chamber with a gauge and flapper valve to hold the pressure static. I think I said that rite???

[clide]

Well if you want useful data with a chrony you will have to weight the ammo before each shot or just use consistent ammo like golf balls. You would have to do the same for this method too, a lighter projectile will have less pressure behind it because of the dynamic losses of faster flow.

And how exactly are you going to determine flow by measuring pressure? The only pressure you will be able to measure with a pressure gage is the static pressure. To get information for flow you need the static and the stagnation pressure. I'm not sure if you can measure that without sticking a probe in the actual flow path, which is a problem since you also have a projectile in the flow path.

Even if you do get the figure it probably won't be very useful since everybody already knows performance in terms of muzzle velocity or muzzle energy. It wouldn't really mean anything to anyone to say that your gun can flow 80 cubic feet per second and changing this variable can increase it to 85.