renegadecow Posted March 21, 2011 Report Share Posted March 21, 2011 Just stumbled on this at Airsoftbuilds.com http://airsoftbuilds.com/weapon.php?id=1199 From what I understand, this guy made some sort of mod on his cylinder to make a 1J spring jump in fps by 80-100 or so he claims. The nozzle is supposedly blocked until the piston compresses and makes maximum pressure before releasing the air. He has no schematic or description of how he did this, but has a proof video on Youtube: Not sure what to make of it if its a hoax or what but technology like that would really be helpful in making gearboxes last longer. I already have an idea on how to do it, with some kind of valve in the cylinder head which is actuated by the piston, but would like to know your thoughts on the matter first before I start making anything. Link to post Share on other sites
Collat3ral Posted March 21, 2011 Report Share Posted March 21, 2011 Some kind of pressure release valve I would guess. I read about this a while ago, don't know if it was schredder or noobie. Link to post Share on other sites
Kenworth W900 Posted March 21, 2011 Report Share Posted March 21, 2011 Best application for this technology would be the Tokyo Marui tri-shot shotguns in my opinion. Link to post Share on other sites
Tom Andrews Posted March 21, 2011 Report Share Posted March 21, 2011 It sounds like the effect you get from burst disc technology as used in model rockets. A sudden release of compressed air giving a dramatic acceleration. Link to post Share on other sites
Collat3ral Posted March 21, 2011 Report Share Posted March 21, 2011 http://en.wikipedia.org/wiki/Check_valve, http://en.wikipedia.org/wiki/Safety_valve Now to make this usefull for Airsoft. Link to post Share on other sites
Docv400 Posted March 23, 2011 Report Share Posted March 23, 2011 I'd be quite suspicious of any video like that, claiming such a jump in fps without really showing anything at all I'd also doubt the integrity of anyone that put's Deans connectors on an AEG, and leaves those poxy tamiyas on as well You could put an M150 spring in an M100 pack, you could also put 0.12g BBs in a container marked as 0.25s, can't see the point though. Thing is, 400fps isn't that amazing even with a lower power spring, if you pre-loaded it, and had a well made piston head, excellent sealing, etc. My son's AUG A3 was firing at 420 'out of the box'. I had to cut the spring down so much to get it down to 350 that it's only approx 10mm longer than the space it fits into (instead of the usual 40-50mm), that's with one of my extended piston-heads (for AoE setting), and it has a ported cylinder! Edit; A properly set-up check valve would indeed open only when the pre-set pressure was reached. Unfortunately, it would also shut off again almost immediately. Link to post Share on other sites
deepsix Posted March 23, 2011 Report Share Posted March 23, 2011 huh. waddyaknow. I've been trying to figure out just such a valve. I wonder what he did? It has to have decent flow to get those readings. The closest I could come up with (but have not yet built) was using the old classic 'bullet valve' technique and placing a tight O ring in front of the BB just at the start of the hop unit to allow pressure buildup. I would love to know what he did here. Magnetic bearing ball/poppet valve maybe? would be useful across the board. Heck, you could lower the spring needs of sniper rifles... or better yet, shorten the cylinder length. Maybe have even smaller and shorter cylinder needs in AEG's, longer battery life, less mechanical wear. Well, I'm glad someone did it. Should become standard perhaps, that kind of increase in efficiency opens up a slew of possibilities. Bravo Link to post Share on other sites
renegadecow Posted March 24, 2011 Author Report Share Posted March 24, 2011 Thing is, 400fps isn't that amazing I was thinking more on guns that barely make it past 300 without breaking like AEPs, UZI's and shotties like Kenworth mentioned. Still, I'm now very skeptical about the whole thing because no matter what valve I think of having in place, it's seriously going to impede air flow anyway because there's not much room to play with between the cylinder head and air nozzle. edit: Best I could think of is a simple valve on the cylinder head that's spring loaded and has the stem extend into the cylinder by a bit. Only when the cylinder compresses to the point where it pushes the stem forward will the valve open. Link to post Share on other sites
deepsix Posted March 24, 2011 Report Share Posted March 24, 2011 Best I could think of is a simple valve on the cylinder head that's spring loaded and has the stem extend into the cylinder by a bit. Only when the cylinder compresses to the point where it pushes the stem forward will the valve open. know what? I bet you're right. A valve opened by the piston would be designable (as long as the piston can overcome the compression 'pillow' of air), and it self-solves the timing of the opening. Link to post Share on other sites
Docv400 Posted March 25, 2011 Report Share Posted March 25, 2011 I think that's the problem with a simple spring-loaded valve. If you're blocking the exit of air from the cylinder, I think it would stop the piston short of the valve release point, especially with a 1J spring. Also, I think you'd get problems with full auto. AEGs are on the verge of premature engagement all the time, deliberately slowing the piston's forward travel is asking for trouble if you ask me.The more I look at the video, the more suspicious I become The guy tells the cameraman to move to the other side of the table just before he inserts the gearbox, then it looks like he's deliberately keeping it out of sight until he puts it in place. Of course he might just be keeping his 'secret' safe, but in the few glimpses you get of the front of the gearbox, there's nothing to suggest an adjustment mechanism, or any valve arrangement. I want this to be a genuine modification, but I'm not convinced at the moment. Link to post Share on other sites
Kenworth W900 Posted March 25, 2011 Report Share Posted March 25, 2011 I think Doc has the measure of this, its just like the ChinaGun MG42, we all WANT this to be true but the likelihood of it actually being real is slim. One reason I personally suspect something is because if this guy had actually created such an inovative system he would be making far more of a fuss about it. Link to post Share on other sites
Docv400 Posted March 25, 2011 Report Share Posted March 25, 2011 Then again, if it is for real, I can see why he'd be so secretive about it. If you were sitting on something like this, then I guess you'd be trying to get something for it by getting a manufacturer interested. Link to post Share on other sites
teflon don Posted March 25, 2011 Report Share Posted March 25, 2011 i cant see this working what ever valve there would be it would restrict airflow, even if it would work the effect would be minimal and basically turning your hop up up would have the same effect (containing the air until a sufficient pressure is achieved) Link to post Share on other sites
P.S.I. Posted March 25, 2011 Report Share Posted March 25, 2011 FWIW, it appears to be a KWA gearbox...I've seen KWAs do strange things, for example...I put a King Arms M110 spring in my KWA M4 and it chronoed at over 450w/.20, after compressing the spring it now shoots 448. The only parts I changed from the OEM parts are KA M110 and a Systema "duricon" piston head. My gun should NOT shoot 448 but somehow, magically, it does. Link to post Share on other sites
mk-23 Posted April 4, 2011 Report Share Posted April 4, 2011 Hi, before all sorry about my english. My name is David Fernandez From Mk23custom.com. I registered in this forum some time ago but I´m always busy . About the mk23 custom cylinder and how it works actually we are waiting for patent and it´s the reason about I can´t explain it at the moment. Please be patient you´ll know about it in the next future. Best regard MK-23 Link to post Share on other sites
Docv400 Posted April 4, 2011 Report Share Posted April 4, 2011 As I sort of suspected. Good luck with the project, and keep us informed how it's going. Link to post Share on other sites
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