A dual power "Dreamair" is a possibility using the twin axle version of the muzzle shown here. In such a gun each wishbone draw would move the piston half way up the gun barrel. Hence for full power you would cock both wishbones, "half power" you would only cock one wishbone.
How many people would be interested in that version I wonder and whether they would find it useful.
P.S. I just discussed this with the inventor and he says the intention is to run any future twin axle gun at 22 atm start pressure, not the 11 atm of the single axle gun which will be available first in carbon fiber. Note that with a completely sealed pressure system the pressure being stated is absolute pressure as the "Dreamair" is not affected by ambient pressure at depth. That means you pump the single and twin axle guns up to 10 atm and 21 atm respectively using gauge pressures. The partial vacuum created in the rear of the gun as the piston is dragged forwards during cocking is why you need to think in atm absolute terms when doing force calculations in order to determine the gun's power and how much effort will be required to cock it.
With a compression ratio of approximately 2.0 the gun will reach 22 atm (single axle) and 44 atm (twin axle) with the piston fully advanced in the barrel bore. According to my calculations the twin axle gun will be at 29.3 atm after the first wishbone draw, hence that will be the start pressure for the next wishbone draw. The attached diagram indicates how this was calculated, the effective compression ratio being 1.33 on the first draw. As start pressure is 22 atm, the pressure is given by 1.33 x 22 which equals 29.3 atm. The area under the graph represents the amount of energy stored in the gun, note that it is not a simple straight line, but a shallow curve. This is because pressure P x volume V is a constant for a given quantity of gas and thus P is inversely proportional to volume changes or mathematically P x V = K (a constant) and therefore P = K/V which can be represented in graphical form as the familiar inverse function Y= 1/X.
How many people would be interested in that version I wonder and whether they would find it useful.
P.S. I just discussed this with the inventor and he says the intention is to run any future twin axle gun at 22 atm start pressure, not the 11 atm of the single axle gun which will be available first in carbon fiber. Note that with a completely sealed pressure system the pressure being stated is absolute pressure as the "Dreamair" is not affected by ambient pressure at depth. That means you pump the single and twin axle guns up to 10 atm and 21 atm respectively using gauge pressures. The partial vacuum created in the rear of the gun as the piston is dragged forwards during cocking is why you need to think in atm absolute terms when doing force calculations in order to determine the gun's power and how much effort will be required to cock it.
With a compression ratio of approximately 2.0 the gun will reach 22 atm (single axle) and 44 atm (twin axle) with the piston fully advanced in the barrel bore. According to my calculations the twin axle gun will be at 29.3 atm after the first wishbone draw, hence that will be the start pressure for the next wishbone draw. The attached diagram indicates how this was calculated, the effective compression ratio being 1.33 on the first draw. As start pressure is 22 atm, the pressure is given by 1.33 x 22 which equals 29.3 atm. The area under the graph represents the amount of energy stored in the gun, note that it is not a simple straight line, but a shallow curve. This is because pressure P x volume V is a constant for a given quantity of gas and thus P is inversely proportional to volume changes or mathematically P x V = K (a constant) and therefore P = K/V which can be represented in graphical form as the familiar inverse function Y= 1/X.
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