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PolarStar F1 HPA Unit for V2 M4 AEG w/ Mini FCU


PolarStar F1 HPA Unit for V2 M4 AEG


What is the F1?

Like the Fusion Engine and JACK, the patent pending F1 is a high performance HPA (High Pressure Air) system which replaces the traditional piston and gears of an AEG with a programmable pneumatic system.


Flow Control 

The unique flow control system uses an integral check valve to regulate the forward speed of the nozzle while maintaining the fastest retract speed possible. This system is also what makes the F1's "2-stage" firing possible. When the nozzle is traveling in the forward direction the check valve is sealed, limiting the speed of the nozzle for greater consistency. When the nozzle reaches the forward position the check valve opens to allow the maximum flow into the barrel. The additional flow is maintained throughout the rearward travel of the nozzle, allowing it to retract without limiting the speed.


Compact and Efficient

The F1 uses a custom solenoid designed by PolarStar and manufactured by MAC Valves. The design allows the solenoid to become an integral part of the system and not simply a a switch to control gas flow. This not only makes the F1 more compact but also minimizes the dead volume inside of the system, increasing efficiency and decreasing response time.


Offset Nozzles 

The F1 is compatible with virtually every AEG gearbox, including those with offset nozzles by using either a centerline or offset front cylinder. The front cylinders are interchangable and a centerline F1 may be converted to an offset F1 by simply swapping the front cylinder and nozzle.


Unlike similar systems, the F1 incorporates a dual purpose flow control system which allows for nozzle speed regulation and two stage firing through an integral check valve. The check valve system regulates nozzle speed based on the direction of movement while also controlling flow to the secondary firing point. This unique design promotes both increased cyclic rate and smoother chambering.


*HPA Air Rig And Regulator system not included and is required.



  • Machined aluminum alloy construction provides superior durability and lightweight design
  • Tool-less design makes in the field maintenance simple and hassle free
  • Delrin air nozzle
  • Can be used with battery packs between 7.4v and 1.08v (7.4v-8.4v recommended)
  • FCU allows for rate of fire, Max semi-auto and selector mode adjustments
  • 2-9 round burst capable
  • MAC manufactured custom solenoid makes the F1 system more compact and efficient
  • Dual purpose flow control system allows for nozzle speed regulation and two-stage firing, increasing cyclic rate and smoother chambering
  • 5 moving parts offers extreme reliability and makes maintenance easy
  • Compatible with most Ver. 2 M4 gearboxes
  • FCU and trigger board included



PSI Operating Range: 40 PSI - 130 PSI (Do NOT exceed 130 PSI, otherwise you may damage the internals)

Compatibility: Tokyo Marui Spec Version 2 Gearboxes
Included Nozzle Type: M4 Series
Rate of Fire: 1 - 30+ RPS (Adjustable)

Material: Aluminum / Delrin
Muzzle Velocity: 500 FPS w/ .20g 6mm BB @ 120 PSI
Fire Modes: Semi / 2 - 9 Round Burst, Semi / Full Auto, Semi Only
Power Source: HPA (High Pressure Air via Remote Air Rig)
FCU Battery: 7-10VDC w/ JST Connector
Package Includes: Pre-Assembled F1 Conversion Kit
Battery: 7.4v-9.6v NiMH or Lipo (Not included).

Manufacturer: PolarStar Airsoft

*Required for Operation:Complete TM Spec AEG rifle with gearbox, Regulated Air Rig & Regulator, HPA Tank, Battery (Sold Separately)


PolarStar Mini FCU


The new PolarStar Mini FCU is a more compact and less expensive option for single-solenoid HPA systems.

New voltage regulators allow for extremely low power consumption in sleep mode. Drawing under 28uA while idle, the Mini FCU is over 300 times more efficient than the original Standard FCU and can operate in sleep mode for close to one year on a small 250mAh pack.

Elimination of the solenoid MOSFET, joystick and LCD, along with careful selection of the remaining components, allowed the size of the Mini FCU to be reduced significantly compared to other FCUs. It's small size allows the Mini FCU to fit inside the gearbox shell keeping the control unit and wire harness protected from damage.

Despite it's size, the Mini FCU actually expands on the functionality of the Standard FCU by adding an integral Motor Control Unit and support for 4-position selectors. In order to make setup as easy as possible the MCU output port can be used with either a box mag or optional speaker to provide feedback during programming.


Ultra-Low Power Voltage Regulator

Like the Standard FCU, the Mini FCU automatically enters sleep mode just seconds after the last shot fired. Unlike the Standard FCU, the Mini draws under 30uA (micro-amperes) while sleeping. In order to achieve such low power usage the Mini FCU uses two voltage regulators to reduce the battery pack voltage to the 5VDC used by the FCU and solenoid. The first is a small regulator with extremely low quiescent current (current draw while sitting idle), used to supply power to the microcontroller. The second regulator is a larger, higher current regulator used to power the solenoid. This regulator is shut down until the solenoid is energized, effectively reducing it's idle current to zero. The combination of these voltage regulators and the IO pin configuration allow the Mini FCU to draw as little as 28uA when in sleep mode. To put that into perspective, the Mini FCU could run in sleep mode for over 300 days on a small 250mAh battery pack.


Extremely Compact Design


Due to the design of the solenoid voltage regulator and the fact that the Mini FCU is designed for single-solenoid 

systems, the MOSFET controlling power to the solenoid was no longer required. The voltage regulator itself is used to control power to the solenoid. When enabled, the regulator powers up in microseconds to energize the solenoid coil.

Remaining components were carefully selected and placed to minimize the board size 

resulting in the most compact Fire Control Unit available. The Mini is small enough to be mounted in place of the spri

ng guide or simply placed inside of the gearbox shell. This completely encloses the wire harness so that there is no way it can be caught and damaged. A #4-40 screw hole is provided on the PCB for mounting to an optional "spring guide base" or just about anywhere else it will fit.


Integral MCU and 4-Position Selectors

Despite its small size, the Mini FCU contains an integral MCU (Motor Control Unit). The MCU allows the full battery 

pack voltage to be switched on and off based on the trigger pull in order to control the box mag motor or other devices that operate at the same voltage as the battery pack.

When the optional speaker module is connected to the MCU port the Mini FCU can provide audio feedback to make programming easier by letting you know what setting you are changing as well as confirming the changes. If a box mag is being used, the box mag motor itself provides the same feedback as the speaker module.

Although the Mini FCU retains the same 5-wire header and harness as the Standard FCU it is only designed to control a single solenoid, leaving one position open. The "extra" position has been reused as an additional input which can be connected to a second selector switch allowing the Mini to handle guns with 4-position selectors.


Programming The Mini FCU

Since there is no joystick or screen, the Mini FCU is programmed through a series of menus controlled by the trigger. To enter programming mode hold the trigger while plugging in the battery. If the trigger is not released after 5 seconds the unit will reset to factory defaults, otherwise it will enter the main menu. The standard menu consists of settings for:

  • 1 - ROF
  • 2 - Dwell
  • 3 - Selector Position 1
  • 4 - Selector Position 2
  • 5 - Max Semi Auto ROF
  • 6 - MCU Enable

Once in the main menu the unit will wait for trigger input.

Installation: F1™ will be installed into the shell of your AEG's gearbox. The only parts which you need to retain from your gearbox is the trigger w/ spring, safety assembly and selector components. Retain the original spring guide for models which require that the stock be secured to the gearbox and not the receiver.

Compatibility Disclaimer: The Version 2 - M4 kit is compatible with most TM Spec AEG's in that rifle series. This kit is compatible with other TM Spec rifles which use a Version 2 gearbox with the traditional open contact trigger switch. In most cases only a model specific nozzle is required to install the system into another model (i.e. M4 to MP5). If your rifle has an electronic micro switch (i.e. Ares Amoeba) you will need to purchase the kit for that specific model series which will include a different switchboard.

Disclaimer on High Pressure Air (HPA) Systems:Only HPA should be used with the F1™ system. CO2 and Propane cannot be used. Using liquid propellants such as this can result in damage to the system.

HPA Tanks are a safe and effective source of power though there are some precautions you must follow. Please follow these proper precautions when using HPA systems:

- NEVER put oil in the fill valve of the tank, or else the tank can combust on refill and serious injury can occur. Lubrication is not necessary in HPA systems.
- ONLY allow properly trained professionals to fill your HPA tank.
- ALWAYS double check your Regulator pressure. Never raise the regulated pressure above 120 PSI
- Make sure to have your tank Hydro-Tested when necessary. (Usually 3-5 years from date marked on tank, depending on make and model)
- Be sure to properly transport your HPA tank. Store in a safe, secured place when in a vehicle, and be sure to stow in a bag or tank cover when in use. Avoid dropping the tank on hard surfaces as this can seriously damage the tank and lead to failure.
- Always turn off the tank and bleed the air line when you are done. This will ensure a longer tank and system lifespan.

Add to Cart:

  • Model: F1V2-M-M4
  • Manufactured by: PolarStar