What is an N7:
The Redline N7 is a Patent Pending HPA drop in cylinder replacement.
It uses a single solenoid, and is designed to replace an AEGs compression cylinder.
The N7 has a forward biased nozzle and fires from a true closed bolt.
What about the mechanical version?
The N7 will be available in 2 versions.
The standard electro-pneumatic version, and the "N7 Milsim" fully mechanical-pneumatic version.
The electro-pneumatic version uses a solenoid, a trigger board, battery and programmable FCU and operates like a standard electro-pneumatic HPA engine. It has select fire, user programmable Semi Auto and Full Auto rates of fire, programmable Full Auto/Burst Mode and adjustable Nozzle Dwell.
The N7 Milsim is the engine for the devote Milsim player. It is Semi Auto only and uses a reliable all mechanical-pneumatic design. The FCU and battery are eliminated and the trigger board and solenoid are replaced with a pneumatic valve, hoses, and solenoid plug.
The trigger feel is fantastic and high semi auto rates of fire are easily achieved. And with no batteries or electronics to fail, playing in the rain/snow is no longer an issue or concern.
Since the base N7 engine body is the same between models, conversion kits will be available that will allow you to convert an electro-pneumatic N7 to an N7 Milsim and vice versa.
The N7 Milsim and N7 Milsim conversion kits will not be available for order at launch but should be available shortly afterwards.
What is the difference between a closed bolt and open bolt HPA engine?:
A closed bolt engine has a forward biased nozzle. That means that when at rest and ready to shoot, there is a bb seated in the bucking, and the nozzle is fully forward and sealed against the bucking lips.
Once the trigger is pulled the bb is shot from the barrel, the nozzle then fully retracts to allow another bb to enter the hop chamber. The nozzle then returns fully forward positioning the bb into the bucking and sealing on the bucking lips.
Typically it takes 2 separate solenoids to make a closed bolt HPA engine function. One to control the movement of the nozzle and one to control the air used to fire the bb (poppet)
This adds cost and user setup complexity.
On an open bolt engine the nozzle is rearward biased. That means that when at rest and ready to shoot, the position of the nozzle is fully rearward. The position of the bb can vary. It can be in the hop chamber or possibly partly or fully in the bucking.
Once the trigger is pulled, air pressure moves the nozzle forward when the nozzle reaches the fully forward position the nozzle seals against the bucking lips and the bb is shot out of the barrel.
Once the solenoids dwell time has expired the air stops flowing through the nozzle and the nozzle retracts.
Open bolt engines can use only a single solenoid, and are typically easier to manufacture since they are of a simpler design. That make them less costly, and can be a bit easier for the user to setup.
Which is better closed bolt or open bolt?
Closed bolt engines are typically considered to have greater accuracy do to more consistent seating of the bb into the hopup rubber (bucking) from shot to shot.
What are the advantages of the N7?
The N7 combines the best features of both designs in one package.
It is closed bolt, so it has the accuracy of a closed bolt engine. It uses only a single solenoid so it has the simple design, form factor and low cost of an open bolt engine.
It quite literally is the best of both designs combined into a single package.
It is also the simplest of all currently available engines open or closed bolt, for the user to setup since there is no poppet dwell to tune.
So why is there a dwell setting on the FCU then, if the poppet dwell does not need to be tuned?
The Nozzle Dwell setting controls how long power is applied to the solenoid. The Higher the value, the longer the nozzle is held in the retracted position.
This is used to adjust for slower feeding magazines. This setting is highly dependent on the Magazine, BB and Hop-Up used. Setting this value too low will result in non/inconstant feeding and jams.
Setting this value too high can result in double feeds. Because of how the N7 is designed, this setting DOES NOT affect how much air is released down the barrel like other systems.
What is the "fixed volume dump chamber" and how does it all work?
Like other typical HPA engines open or closed bolt, the N7 fills an internal chamber at the pressure set by the users external supply regulator.
The difference is, rather than relying on a solenoids dwell to control the volume of air used to propel the BB the N7 controls the air mechanically. It does this with an internal spool valve.
When fired, air pressure is removed from the backside of this spool valve via the solenoid. This causes the spool valve move rearward.
As the spool valve travels rearwards several thing happen in sequence. First the poppet opens sending ("dumping") air down the nozzle to propel the bb out of the barrel. At almost the exact same time the spool valve shuts off the regulated air supply to the chamber. This means that there is almost no air flow through the engine from the regulator once the firing sequence starts. Hence the "fixed volume."
As the spool continues rearwards it switches the air normally used to fill the chamber to the front of the nozzle. This causes the nozzle to retract so that another bb can be loaded into the hop chamber.
After the dwell setting of the solenoid expires, the solenoid allows air back in behind the spool. This starts to drive the spool forward again.
As the spool travels forward, several thing happen in sequence again. First the air pressure to the front of the nozzle is removed and the air is vented back out via the spool.
Next, at almost the exact same time, the spool valve re-connects the air chamber to the regulated air supply and the closes the poppet sealing off the nozzle from the chamber. The air chamber refills driving the nozzle back forwards in the process.
This feature of mechanically sealing the air chamber contributes to the N7's excellent shot to shot consistency, with no air wasted do to improper dwell settings.
And while not completely eliminated, this design also results in the N7 having less "Joule Creep" when different BB weights are used when compared to other HPA engines.
Can I use any hop rubber (Bucking) with the N7?
Yes, due to the N7 being closed bolt, and with the ability to precisely control nozzle dwell via the FCU you can use pretty much any bucking you want. Just like with a Fusion Engine you get the accuracy benefits of the closed bolt design and as long as your nozzle dwell is not set excessively long double feeding is not an issue.
Can I use any hop rubber (Bucking) with the N7 Milsim?
With the N7 Milsim the answer is it depends.
While you still get the benefit of increased accuracy do to the closed bolt design of the N7 Milsim, some users, depending magazine and bucking used, may experience some double feeding issues.
Do to the fact that the N7 Milsim is fully mechanical the nozzle dwell is controlled by the users trigger finger.
As long as the trigger is depressed the nozzle is held rearwards. Since it is not possible to precisely control the nozzle dwell in this way there is the possibility of double feeding do to high magazine spring pressure and excessive nozzle dwell.
If you find double feeding to be an issue we recommend that you use a Madbull red bucking or any bucking with tight feed lips.
MAP price of an N7 is $355
MAP price of an N7 Milsim will be $310.00
MAP price of an N7 to N7 Milsim conversion kit (converts electro pneumatic to mechanical pneumatic) will be $65.00
MAP price of an N7 Milsim to N7 conversion kit (converts mechanical pneumatic to electro pneumatic) will be $110.00