HUNTER HPA HYBRID CONVERSION KIT – WHAT IT IS AND HOW DOES IT WORK
HUNTER is a hybrid HPA engine designed for installation in electric gun replicas equipped with V2 and V3 gearboxes. It is called a hybrid for it combines the best features of electric drives along with the performance and capabilities of HPA systems. It allows to transform the drive of a gun replica from purely electrical to gas. Depending on the length of the barrel and the set pressure, it may serve as the drive for replicas intended for CQB as well as the strongest sniper rifle replicas.
“…I could pour a handful of sand into the rifle, retract the bolt latch and shoot!”
During prototype works the creators conducted a test where HUNTER was tested grease-free in semi- and full-auto modes at -10°C. No problems were detected in terms of functioning even after several thousand shots fired. Despite the obtained results, using HUNTER without lubrication can cause damage to the o-ring, therefore it is not recommended.
WHAT DO WE GAIN BY USING THIS SOLUTION
Using drive gear yields an abundance of benefits. The basic is the already mentioned seamless operation at any pressure range. Due to a large stock of power, resulting from the use of an electric motor, for HUNTER there is no difference whether it operates at 3 or 11 bar. At the same time, such excess makes power consumption several times lower when compared to AEG replicas. Imagine that you own a light car in which you install a very powerful engine. It rides perfectly and, at the same time, it does not burn much fuel. Thus, you can successfully apply batteries with smaller capacities. This is however not a requirement. The kit may be also charged by batteries with higher capacities, the only difference here will be a longer duration of discharge.
ELEMENTS REQUIRED FOR PROPER FUNCTIONING OF THE KIT
HUNTER fits in almost all V2 and V3 gearboxes. The exception are V2 versions with additional reinforcement in the area of the pinions and the spring guide.Installation in such cases is possible yet requires more advanced modifications.
HUNTER replaces these components. You can remove and forget about them.
Due to its manner of functioning and scope of work, HUNTER requires to stop the system in resting position immediately after firing a shot. The effect of partial spring tension known from AEG platform is unwanted here. It may contribute to incorrect propeller dosing, firing empty shots, deterioration of trigger response, etc. Therefore, do not use the conversion kit without a mosfet equipped with a brake and do not turn off this feature, even in systems in which this option is available. This also applies to the use of full-auto mode in electric replicas not equipped with cycle detection.
– ADVANCED MOSFET SYSTEMS
The most preferred type of drivers are those equipped with pinion cycle detection. This solution allows to take full advantage of the possibilities offered by the conversion kit. Thanks to thorough control over the mechanism, they provide the ability to use the device in semi-auto, full-auto as well as burst mode along with its derivatives. Such systems are often equipped with extensive options. It is important to remember to never deactivate the ACTIVE-BRAKE feature and do not use PRE-COCKING. The reason for the first condition is described above and the effect of initial spring tension constitutes an integral feature of HUNTER. The total work of the core of the conversion kit closes at a distance ~10 mm and the opening of the valve is turned on by the core at around half of this distance. Due to the combination of this correlation with the phenomenal responsiveness of the system due to low overload, the shot is fired almost immediately after the pull of the trigger. The use of PRE- COCKING could also contribute to firing empty shots and unnecessary loads on the conversion elements.
– SIMPLE MOSFET SYSTEMS
The second group of mosfets are the simple systems not equipped with cycle detection, but equipped with ACTIVE-BRAKE feature. Such drivers give the ability to handle the conversion kit only at single fire mode. This option is dedicated to users wishing to use HUNTER for sniper purposes, where full-auto is not required. It should be noted that the possibility of switching the fire mode to continuous fire should be blocked by the user of the replica. The use of this mode may lead to malfunctions similar to those in case of using HUNTER with mosfet without the active brake feature. However, there is a way to use the system without cycle detection, not only in the single fire mode. Such opportunity is ensured by features with programmable BURST time. Smooth operation of the system can be maintained upon appropriate calibration of this parameter. However, it should be noted that modifying the reducer or using another battery may cause the need to re-calibrate the system. With this option it is not advisable to use power sources which significantly change their output parameters in the course of discharge.
HUNTER comes with a dedicated module that replaces piston sprockets and fits the standard type AEG-type pinions. To ensure proper functioning of the system it is necessary to have an engine and middle pinion with 18:1 transmission ratio, available in factory-made gearboxes. Due to the design of the conversion kit, it is not necessary to use expensive, reinforced gears. Use of the anti-reversal latch depends on the installed Mosfet driver. It should be removed only if the manufacturer recommends it, in other cases it should remain in place. It is also worth mentioning the ongoing works on the DUAL SECTOR GEAR module. In the future, it will allow to significantly increase the rate of fire offered by HUNTER.
In HUNTER, correct adjustment of pinions is just as important as in the case of electric replicas. The only additional guideline is to ensure that upon shimming of the module supplied with the kit the slide surface corresponds to the maximum extent with the working surface of the core latch. The quality and accuracy of the adjustment will affect the functioning, power consumption and, in extreme cases, the possibility of damaging the unit.
Electric engine used for HUNTER is loaded to a negligible extent. Thus, the weakest engines, such as those installed in most replicas, are sufficient. But there may occur a situation where the brake will not be able to properly stop the pinions in the place designated by the cycle detector. This may result from using batteries with high voltage and power efficiency as well as using continuous fire mode where, after several seconds, the engine and gears are accelerated so that their stop requires using greater force. This problem may be solved by using an engine equipped with more powerful magnets. Producers of mosfets with cycle detection often recommend the use of HighTorque engines when using replicas with weaker springs. In this case HUNTER ought to be interpreted as a spring with extremely low rating and in compliance with the guidelines from the mosfet manufacturer.
HUNTER works with all types of batteries used to power AEG replicas. The suggested type of battery is LiPo. The nominal voltage should be 7.4V or 11.1V. It is also worth underlining that the choice of battery voltage translates into the rate of fire of the kit. With voltage of 7,4V the rate may amount to approximately 18-20 RPS, while in the case of 11.1V – approximately 25-28 RPS. The result depends on the applied power source, parameters and the condition of the electric motor as well as the quality of shimming and mosfet efficiency.
TAPPET PLATE/AIR NOZZLE
HUNTER uses the classic tappet and nozzles designed for AEG systems. The only necessary modification is to shorten the hitch of the tappet’s strip so that the nozzle can return to its free position during the contact between the gear and the core latch, at the latest. A detailed description of this operation can be found in the assembly instruction.
TRIGGER SWITCH/CUT-OFF LEVER/SELECTOR PLATE/WIRING
Due to the construction of HUNTER, electrical components and peripherals of the fire selector cannot be modified. One deviation from this rule is to adapt to the requirements from the manufacturer of the mosfet applied in the replica.
The functioning of HUNTER does not burden the bearings even in the extent known from AEG platforms, so there are no special recommendations on this matter.
GAS SUPPLY FOR CONVERSION KIT
HUNTER kit is equipped with a supply hose with dimensions of 6/4 mm. It can be supplied only to the rear side of the replica, under the guide rail of the gunstock. It is not possible to enter it through the pistol grip. This is a result of leaving the electric engine and the pinions in place. Ways to lead the hose from the replica are described in the assembly instruction.