Intank regulator project…
Hello Guys,
I thought I publish my project so far. I have been designing new regulator which will go inside main tank. The reasons are simple;
-it won’t take space between gun and tank
-it’s safe since everything is inside tank
-the big forces are all gone and replaced from stretching to compress
-there is good space for relatively big size regulator chamber which is needed (25ccm) for low pressure and wider pressure-range (more usable shots)
-the firing valve is separated from regulator design so one could use any valve available (although it needs connection thread for regchamber)
I already built two prototypes and tested them on dedicated testbench. The regulation works. I did few hundred of strokes and it regulates the pressure everytime to set value. I still need to examine different poppet-valve sealing materials since I am not 100% happy with current implementation. Over few hour period there is some pressure grawling noticeable meaning that first shot will be little faster than rest.
The difficulty for Talon regulator is the filling. It has to be able to handle bigger forces during filling and also has to pass trhough the air from regchamber to the tank. That was the reason for “inventing” poppet-valve to the regulator. It handles both. Eliminates the bigger forces against regulator-sealing and acts as oneway-valve during filling.
The regulator is designed for 300bar and the regulator body can handle 3x that pressure when it comes to strength.
When used with 100bar pressurerange the accuracy from first to last shot is about 1.6% leading to 1.2m/s velocity drop over whole range. Of course there is little bigger variation during string because of other factors.
This is how it should be assembled to the gun….
The princible of regulator…..
-spring lifts poppet-valve’s stem and air starts to flow from tank over valvestem to the regulator chamber
-pressure in regchamber raises and exceeds springdiscs force and regulator pistons moves to the right. Poppetvalve closes.
-shoot and the cycle restarts
-during refill the overpressure in regulator chamber (against tank) will push the poppet-valve open and air will flow to tank
-the regulation pressure is adjusted with big M14x0.5 thread in the “tophat”
-do realise that the flowchannel in poppetvalve is 10x smaller than through the regulator piston. The pressure is always same one bothsides of piston’s heads. So don’t get confused about the “reverse” design.
The parts….
Prototype number two…
Poppet-valve and integerated sealing…
About the scale of parts….
Bench testing….
In the bench the regulator is inside aluminium tube…
It’s not ready yet but it’s a step closer to our common goal… regulated Talon which can shoot consistent shots with wider pressure-range and wider ME range. Next I need to build or get main firingvalve to be able to perform some fieldtests with gun.
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Just like before.
Thats the beauty of Twin Piston 😛 (I love that word. lol)
During refill the second piston operates as oneway valve. The bigger pressure in regulator chamber forces the piston to open and air is bleeding through 0.5mm bleedingvalve to tank side.
And btw, I am proud to announce that I just shot first 60+65 shots with my Regulated Talon. (125 consistent shots starting from 150bar only and ending to sub 100 bar). I shot two sessions (with single fill) couple of hours inbetween and the velocity was same during both strings.
I was able to make my valvestem today afterall. Nothing fancy, just a quick proto without separate tophat.
So. I shot with 100bar regulated pressure. Yes only 100 bar!
Tank was filled only to 150bar since I didn’t like to push my luck with my new valve :). And like I said I shot 125 total CONSISTENT shots with 850fps (14gr = 23FPE). Average velocity stayed same during the string. Some slight (few fps) shot-to-shot variation which I get also normally. Don’t get fooled about midrange power. That was just first test with first settings. If I fill to normal 200bar I bet I can shoot 200+ shots with 850fps with standard Talon tank. Not to even mention what is achievable with 250+ bar tanks.
I didn’t check the pressure at the end but I assume it was way lower than 100bar since the total energy I used was near 4000J (calculated from ME times shotcount). If I subtract 4000J from 150 bar the end pressure should be 70bar with 100% efficiency so I suppose it’s near 60 bar. Think about it. With only 60bar Talon STILL shoots 850fps. And another interesting sidenote; the main valve semi-regulated quite nicely from 100->60 bar 🙂
Anyway. Tomorrow I adjust reg.pressure little higher and next week will make new valvestem with bigger stroke and bore to gain more knowledge about stuff.
Now it’s time for some beer! Cheers guys,
ps. Buba; thanks but I still think you guys credit the machining too much. It only took couple of hours for that valvebody and most of that time was polishing 😀
It’s a shame though that it won’t show up after blackening it.