1385+ shots = 68/4500

[bigred76]

I see what you're saying, now. I forfeit (Only time you're gonna hear that one from me....). It's just too much math for a simpleton like me to do, and I don't have the equipment to do it will. Hell, I don't even know what I'd use to test it, lol!

[calebh]

so i was right that dryfires take more air. yay.

so just for my own info, is the valve open any longer when a blowback is fired without a ball in the breech?

[bigred76]

No, you're not right, Drago is.

Read Drago's post more carefully, I'm too tired at this hour to restate it.

[DRAGON]

I would guess the dwell duration is the same whether there is a ball in the barrel or not. It is controlled by springs not pressure. It's really no secret that you can depleat a tank full of pressure much more expeditiously with no paint -

[calebh]

Originally Posted by me

more air IS used when dryfiring

Originally Posted by DRAGON

When there is no ball in the breech and a shot is taken, it uses more propellant because there is nothing stopping the pressure including the LPC storage from depleating as much as it can for the duration of the dwell time. W/A ball in the barrel, the ball is actually buffering/blocking the maximum flow of pressure for that quick ms and by the time the ball leaves the barrel the valve is closed. Less pressure has been used because the valve is closed before the ball that's blocking the maximum flow of pressure has left the barrel

Originally Posted by me

so i was right that dryfires take more air. yay. (emphasis added)

so go yourself. after you read more carefully.

my valve theory may be wrong. i dont think so. but it may be.

[bigred76]

I was kidding... Yeesh...

This is basically the answer to your theory:

Originally Posted by DRAGON

I would guess the dwell duration is the same whether there is a ball in the barrel or not. It is controlled by springs not pressure.

[calebh]

Originally Posted by DRAGON

I would guess the dwell duration is the same whether there is a ball in the barrel or not. It is controlled by springs not pressure. (emphasis added)

its controlled by springs, but the pressures involved seem to play a role. unless someone wants to set something up and measure the diff, i dont think this discussion's goin any further. good luck lol

[bigred76]

Yes, the pressure on the cupseal helps it stay closed. That would be common sense, agreed? Now, let's say the marker runs at 300psi. You can raise the pressure through the vertical regulator to stiffen the valve spring, and lower it to soften. Odd, eh? Well, it's because of that pressure on the cupseal holding the valve closed. The more pressure holding it closed, either by an air mass or a spring, and it will have a lower dwell. Softer, and it will have a higher dwell, because the valve is knocked open more or less. This is actually how you tune springs for an Autococker, but I find it transferable to Spyders as well.

Just a minor explanation of how valve dwell works on blowbacks.

And... Drago's "guesses" are almost sure enough to bet on. Stick around long enough and you'll learn that.

[calebh]

Originally Posted by bigred76

Stick around long enough and you'll learn that.

haha, ive been around a long time i took a long break and missed the changeover on the forums, and im just now starting to become active again, but i have been around lol. a guess is still just a guess.

im not meaning operating pressure when i say the pressures involved. i know how all that works. again, ive been around a long time im meaning mainly the pressure created by a ball in the breech, or lack of one, affecting everything else. since i havent been disproven yet, im still going with my own experience and the conclusions i draw from that.

[DRAGON]

I emphasized the word guess because it would really depend on what pressure and what springs pertained. Did I mention components & flow properties? There are so many variables that one could only guess what significance pressure would have on dwell. I will stick my neck out and say pressure would have no significant affect on dwell duration in a stbb. The springs are obviously the main determiners of that -

In an EP marker the dwell duration is controlled by the board commanding a duration of flow through the noid. The dwell will always be the same(set to a particular ms increment in thousandth's of a second) whether the pressure has been changed or whether there is a ball in the barrel or not. The only thing that pressure dictates is the amount of flow that goes through the marker. A stbb isn't very much different besides the fact that it uses springs which makes a world of difference in price as opposed to that expensive $100 noid and added chipped program to the board -