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Carl Quick's LiteWieght 2240

So for about the last 24 months, I've had her on a serious diet. Now I am happy to report that she lost nearly 13 ounces and is feeling so much better. And let me say one thing, when I pick her up with one hand now she is light as a feather. Well, almost a feather.

Things I have done so far:

OEM main tube was lightened by me.
Barrel is OEM and trimmed down by me.
Main tube plug is made of Delrin by me.
Gas cap is aluminum, comes from HPA and bored out by me.
Hammer is made from Delrin by me with a modified 1701P striker.
Valve is an aluminum Disco rear end with a brass Pro-Top by Anthony.
Trigger grip frame is aluminum by Bluefork Design and then hogged out by Gregg.
Front barrel band is aluminum, made by Anthony, drilled by Rich and milled by me.


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I strive for 1cc per FPE I want....

June 19 2012 at 7:25 PM
rsterne  (Login rsterne)
from IP address

Response to about volume

but that's not strictly the valve volume, but the volume available for the valve to draw from easily.... eg. easier flow into the valve than out.... It's based on the concept that the larger the volume available, the higher the pressure will be at the valve seat DURING the shot cycle.... There are a large number of variables, but here is a graph showing why I use that as a goal....

[IMG][linked image][/IMG]

This graph is based on the average pressure for different sized resevoirs for the valve to draw from between a 2000 psi regulator and the valve seat, for a gun that is generating 1 FPE/CI of air used at 1 bar (ie an efficiency of 16.4 Barcc/FPE).... Cutting the volume in half (from 50 cc to 25) loses about 8% of the average pressure, whereas doubling it to 100 cc only gains about 3%.... Reducing the valve volume to 15 cc would lose about 16% of the average pressure, and if it was just 10 cc, the loss would be about 28%....

While the details of the curve will depend somewhat on the specifications of the gun, the trend should stay more or less intact.... It doesn't mean that you can't get by with a smaller valve.... but what it does mean is that as you reduce the valve (and reservoir) volume you will have to increase the starting pressure to maintain your FPE goal....


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