Speed= Posted October 1, 2009 Report Share Posted October 1, 2009 so what is an NPS? Quote Link to post Share on other sites
stickyittoyou Posted October 1, 2009 Report Share Posted October 1, 2009 NPAS.... HAH! T_HUM! Let's see your first. Â /\ See? Quote Link to post Share on other sites
stickyittoyou Posted October 1, 2009 Report Share Posted October 1, 2009 so what is an NPS? Â Negative Pressure System Quote Link to post Share on other sites
phantomwarrior Posted October 1, 2009 Report Share Posted October 1, 2009 What are the pros of a negative pressure system anyway? Â I remember reading something. Doesn't a positive system use the bb to hold the valve open? Â Is a NPS more consistent? Quote Link to post Share on other sites
Raven1 Posted October 1, 2009 Report Share Posted October 1, 2009 (edited) Kai Wolf,  The front sight and stock you listed will fit with out any modifications and you are good to go. If you're having doubts just swap a standard AEG A-Frame front sight and you'll see it will line up and work no problemo!  Well it seems things are getting somewhat convoluted!  If there will be no official pressure regulation from TK then t_hum and I will have one available shortly. Pressure will be adjusted by simply swapping a simple part. But more on that once t_hum and I have gathered more data and perfected our process.  Negative Pressure System By allowing the valve (or in Kobayashi-san's design a plunger) to remain OPEN in its natural state. Gas is fired out of the nozzle to propel the BB, and continues to release gas as the BB travels down the barrel. The pressure behind the plunger builds to a higher amount than what's in front of the plunger (the front of the bolt cup), and the result is the valve being forced shut. Pressure from the expanding gasses is building in the BCG pushing the plunger closed; sealing the inside of the BCG, causing the piston to push the carrier back into the buffer. Moving the BCG and buffer into the buffer tube causing 1 cycle to happen. Again, once the valve is closed, all gas pressure builds up and is redirected into the blowback cycle of the operation.  Positive Pressure System In the Positive Pressure System, the valve is CLOSED in its natural state, and requires a positive pressure against the nozzle in order to open the valve to allow gas to travel through the nozzle. In this case, the BB is the positive pressure, pushing the reed back in order to open the valve. Once gas is released, gas is continually expanding through until the BB is far enough down the barrel to allow the reed valve to naturally close (under spring power), which then redirects all gas power to the blowback cycle.  Differences  NPS in the KJW M4 uses the expanding gas to overcome spring pressure to shut the plunger for the blow back cycle. One spring is being employed to keep the plunger open. One O-ring is present on the plunger for sealing.  PPS requires an object (in this case the BB) to hold open a reed valve in order to propel the BB. Then relies a spring to return the reed valve to it's normally closed state. This design is not optimal as it is inside of a working BCG that is experiencing the shock and impact of the blowback cycle. Consistency depending greatly on the state of the reed valve and reed valve spring.  Both of Negative Pressure System and Positive Pressure System work on the principle that gas is allowed to flow forward to project the BB. And as the BB moves, the valve then shuts off and 100% of all remaining gas is re-directed to begin the blowback cycle. The projectile always leaves the barrel first, before ANY type of automatic self cocking completes. Edited October 1, 2009 by Raven1 Quote Link to post Share on other sites
tome Posted October 1, 2009 Report Share Posted October 1, 2009 dur..... so basically people have be singing from the rooftops about a feature "coming" on the TK M4 that the KJ m4 already inherently has haha. Quote Link to post Share on other sites
stickyittoyou Posted October 1, 2009 Report Share Posted October 1, 2009 Kai Wolf, The front sight and stock you listed will fit with out any modifications and you are good to go. If you're having doubts just swap a standard AEG A-Frame front sight and you'll see it will line up and work no problemo!  Well it seems things are getting somewhat convoluted!  If there will be no official pressure regulation from TK then t_hum and I will have one available shortly. Pressure will be adjusted by simply swapping a simple part. But more on that once t_hum and I have gathered more data and perfected our process.  Negative Pressure System By allowing the valve (or in Kobayashi-san's design a plunger) to remain OPEN in its natural state. Gas is fired out of the nozzle to propel the BB, and continues to release gas as the BB travels down the barrel. The pressure behind the plunger builds to a higher amount than what's in front of the plunger (the front of the bolt cup), and the result is the valve being forced shut. Pressure from the expanding gasses is building in the BCG pushing the plunger closed; sealing the inside of the BCG, causing the piston to push the carrier back into the buffer. Moving the BCG and buffer into the buffer tube causing 1 cycle to happen. Again, once the valve is closed, all gas pressure builds up and is redirected into the blowback cycle of the operation.  Positive Pressure System In the Positive Pressure System, the valve is CLOSED in its natural state, and requires a positive pressure against the nozzle in order to open the valve to allow gas to travel through the nozzle. In this case, the BB is the positive pressure, pushing the reed back in order to open the valve. Once gas is released, gas is continually expanding through until the BB is far enough down the barrel to allow the reed valve to naturally close (under spring power), which then redirects all gas power to the blowback cycle.  Differences  NPS in the KJW M4 uses the expanding gas to overcome spring pressure to shut the plunger for the blow back cycle. One spring is being employed to keep the plunger open. One O-ring is present on the plunger for sealing.  PPS requires an object (in this case the BB) to hold open a reed valve in order to propel the BB. Then relies a spring to return the reed valve to it's normally closed state. This design is not optimal as it is inside of a working BCG that is experiencing the shock and impact of the blowback cycle. Consistency depending greatly on the state of the reed valve and reed valve spring.  Both of Negative Pressure System and Positive Pressure System work on the principle that gas is allowed to flow forward to project the BB. And as the BB moves, the valve then shuts off and 100% of all remaining gas is re-directed to begin the blowback cycle. The projectile always leaves the barrel first, before ANY type of automatic self cocking completes. ^How long did it take you to write this? lol, just asking. ^ Quote Link to post Share on other sites
Raven1 Posted October 2, 2009 Report Share Posted October 2, 2009 ^How long did it take you to write this? lol, just asking. ^ Â About 45 minutes, but hey, I'm just trying to help,,, Quote Link to post Share on other sites
Speed= Posted October 2, 2009 Report Share Posted October 2, 2009 About 45 minutes, but hey, I'm just trying to help,,, Â Dinner's burning Quote Link to post Share on other sites
enjoi74 Posted October 2, 2009 Report Share Posted October 2, 2009 About 45 minutes, but hey, I'm just trying to help,,, Â What can I say, we need more people like you Raven1. Quote Link to post Share on other sites
Raven1 Posted October 2, 2009 Report Share Posted October 2, 2009 Dinner's burning  Wifey made dinner but I was at the bar eating with the boys after the softball tourney.  Seriously, just trying to help,,,, + it helps that everyone here on Arnie's is easy to post with,,,, Quote Link to post Share on other sites
stickyittoyou Posted October 2, 2009 Report Share Posted October 2, 2009 Wifey made dinner but I was at the bar eating with the boys after the softball tourney. Seriously, just trying to help,,,, + it helps that everyone here on Arnie's is easy to post with,,,,  yeah it was just a question; very good information .   OKAY back on topic. Quote Link to post Share on other sites
sandstorm Posted October 2, 2009 Report Share Posted October 2, 2009 Hmm, quick Q, has any of you KJW owners fitted this SFW barrel to their M4? Â I assume it would take some minor fitting to get the whole barrel to fit since the KJW didn't utilize outer barrel in assembly method? Quote Link to post Share on other sites
Raven1 Posted October 2, 2009 Report Share Posted October 2, 2009 Hmm, quick Q, has any of you KJW owners fitted this SFW barrel to their M4? I assume it would take some minor fitting to get the whole barrel to fit since the KJW didn't utilize outer barrel in assembly method?  I don't believe anyone else other than myself has had an AEG barrel machined a barrel to fit onto KJW. There are 2 extra cuts that need to be made in order for the AEG barrel to work properly.  Short answer is No, the barrel you linked will not work,,,,until the machining cuts are made. Quote Link to post Share on other sites
enjoi74 Posted October 2, 2009 Report Share Posted October 2, 2009 Do y'all think the PDI 01 Inner Barrel for Western Arms (WA) M4A1 Series (324mm) will work on the KJW M4. Here is the link: http://www.redwolfairsoft.com/redwolf/airs...il?prodID=24720 Â Also, has anybody tried the PDI 01 6.01mm Precision Barrel for Marui VSR-10 on their KJW M4 yet. Do yall think is it possible to modify a VSR-10 hopup bucking to work on the KJW M4. Quote Link to post Share on other sites
MrTreble Posted October 2, 2009 Report Share Posted October 2, 2009 All the inner barrels are brand and model specific, so I wouldn't buy one just to see if it fits. Â The WA hop up design is completely different from the KJ design, so that alone would suggest that the inner barrels are different designs as well. Same could probably be said about the VSR10 barrel. Quote Link to post Share on other sites
stickyittoyou Posted October 3, 2009 Report Share Posted October 3, 2009 Any updates guys? Quote Link to post Share on other sites
Raven1 Posted October 3, 2009 Report Share Posted October 3, 2009 Do y'all think the PDI 01 Inner Barrel for Western Arms (WA) M4A1 Series (324mm) will work on the KJW M4. Here is the link: http://www.redwolfairsoft.com/redwolf/airs...il?prodID=24720 Â Also, has anybody tried the PDI 01 6.01mm Precision Barrel for Marui VSR-10 on their KJW M4 yet. Do yall think is it possible to modify a VSR-10 hopup bucking to work on the KJW M4. Â The barrel you listed Will NOT Work, defferent design altogether. Â The barrel you want that will work is this barrel here http://www.redwolfairsoft.com/redwolf/airs...il?prodID=23548 as it has the exact same cut as the stock KJW barrel to work with the KJW hop up,,, Quote Link to post Share on other sites
stickyittoyou Posted October 3, 2009 Report Share Posted October 3, 2009 The barrel you listed Will NOT Work, defferent design altogether. The barrel you want that will work is this barrel here http://www.redwolfairsoft.com/redwolf/airs...il?prodID=23548 as it has the exact same cut as the stock KJW barrel to work with the KJW hop up,,,  Ouch! for me that would be a 200 dollar precision barrel ordering through redwolf. Is there a different place to buy one of those on? Quote Link to post Share on other sites
Donut Posted October 3, 2009 Author Report Share Posted October 3, 2009 It doesn't have to be THAT one, any barrel with the same cut would work. Â Quote Link to post Share on other sites
stickyittoyou Posted October 3, 2009 Report Share Posted October 3, 2009 It doesn't have to be THAT one, any barrel with the same cut would work. Â Yeah I know that much! Â I've been trying to find VSR-10 barrels and so far I have only seen some more like AEG barrels. Still looking around though. Either way I think I will be happy with the stock barrel (for a while) Sooo has anyone even bothered checking out the groupings of this gun? Or did I entirely miss that page? hahah Quote Link to post Share on other sites
enjoi74 Posted October 3, 2009 Report Share Posted October 3, 2009 I think I will wait one more month to see if there is going to be a after market inner barrel from laylax. It is probably going to be cheaper than the PDI one. But I will probably going to give in and get the PDI VSR-10 inner barrel. Quote Link to post Share on other sites
phantomwarrior Posted October 3, 2009 Report Share Posted October 3, 2009 I think I will wait one more month to see if there is going to be a after market inner barrel from laylax. It is probably going to be cheaper than the PDI one. But I will probably going to give in and get the PDI VSR-10 inner barrel. Â There already is a 303 mm barrel from laylax/Prometheus/first factory (all same) as well as a 430mm. Both can be used in this gun, one being about 60 mm short and the other being 70 mm long. Isn't the stock barrel short either way? Quote Link to post Share on other sites
Raven1 Posted October 4, 2009 Report Share Posted October 4, 2009 Yep, Â Sorry guys I was only listing that one as an example, waaaayyy Pricey! Â And Yes the stock inner barrel is short, I cut my KJW outer barrel down on a lathe to 10.5" and the inner barrel is still well inside the outer barrel,,, Quote Link to post Share on other sites
stickyittoyou Posted October 4, 2009 Report Share Posted October 4, 2009 Yep, Sorry guys I was only listing that one as an example, waaaayyy Pricey!  And Yes the stock inner barrel is short, I cut my KJW outer barrel down on a lathe to 10.5" and the inner barrel is still well inside the outer barrel,,,  Hmmm, well I think when I get one I'll have to get a new outer barrel. I think I'll go XM177 Length. I intend to have my silencer on it so it'll hide the inner barrel. Quote Link to post Share on other sites
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