The GUNfet brand is owned by production-design company named Solitech which operates in Gdańsku since 2003 roku. Until recently, their main field of operation was designing electronic components and software. Today, Solitech deals in: component purchases, manufacturing PCBs, assembling contract SMTs and THTs, per order software development, testing, circuits milling , electronics design, creating their own devices.

The company is constantly developing, therefore invests in newest equipment, expanding its machine park, cadre of specialists and their own interesting ideas for new products. Its employees are people with passion, eagerness to constantly broaden their knowledge and qualifications.

Thanks to experience in the electronics business and employees who are airsoft enthusiasts, the GUNfet brand was created. The main aim of this project is to create new, reliable products for airsofters – made in Poland from start to finish. GUNfet is constantly working on development of their products and introduction of new solutions.

BluFET

The first product of GUNfet dedicated for the airsoft market is an advanced, microprocessor containing bluFET circuit, which looks quite plain but is controlled in an interesting and innovative way. The circuit has several functions including some new ones which were unavailable in the previous models mounted outside of the gearbox.

The manufacturer delivers its product in a well protected and nicely looking box.

From the outside the circuit resembles its competitors such as WARFET, of the MERF which is well know among airsofters.

The set contains:

• the bluFET circuit
• a set of signal wires (2 types)
• T-Deans connectors and shrink tubes
• T-Deans – Tamyia adapter
• a sticker
• a leaflet with the MAC address and QR code and a link to download the software
• 2 wire ties
  
  

The manufacturer places this product in the premium segment, therefore I decided to review it in comparison to other products from this price range.

Installation

The circuit installation is very easy. Instead of the power wires (the red ones) you connect two signal wires to the trigger switch. There is also an alternative way of installation in which you don't have to replace the original wires by using just one signal wire (you can find more on that in the manual).

The MOSFET is connected with the T-deans connectors and a goldpin connector and that permanently installed inside a chosen place in the replica. Unfortunately, replicas from the AR family with a collapsible or folded butt stock, makes the installation uncomfortable and in most cases prevents from housing the battery inside the stock guide. In case of replicas with a fixed stock the installation is much easier and it won't impact the ability to house the battery inside the replica that much.

Warning! The circuit uses sensors that detect the working of the motor and an accelerometer to detect if the replicas was fired. Therefore it is necessary to firmly and permanently fix the circuit inside the replica using a double-sided duct tape, wire ties or hot glue. If we don't do that we some of its functions will not work properly.

Functions overview:

• Mosfet – using it makes the high current that flows to the motor to bypass the trigger switch which results in quicker reaction to the trigger pull, higher ROF and extends the life of a replica.
• AB (Active Brake) – it allows to stop the motor quicker after the trigger is released, which helps to improve the working of the gearbox in single fire mode and prevents double shots to occur.
• Burst Mode – this option allows to set the length of burst after the trigger is pulled.
• ROF Control – allows for setting the rate of fire by regulating the motor's power.
• Precocking – this makes the piston remain in the rear position and result in almost instantaneous reaction to the trigger pull. First such feature was introduced by Toki Marui in their PSG-1 replica.
• Cycle Completion – this forces the replica to make a complete firing cycle once the trigger is pulled. Additionally, the spring will always be decompressed after a shot is made.
• Overheat protection - self explanatory.
• Overcurrent Protection - protects the motor, the battery and the transistors from short circuits.
• Dynamic Battery Protection - controls the battery charge level and protects it from over discharging. 
• Moisture Protection - bluFET has a special anti-moisture coating.
• Shots Detector - by combining the motor workings sensors and an accelerometer we get a very precise shot detector.
• Gesture control - by turning the replica (like in quick magazine changing) in a specific way, we can change the MOSFET's operation mode.
• Programming via smartphone.
• Access to myGUNfet.com.

Configuration

After installing the MOSFET and connecting to it via a smartphone and launching the application, a calibration is required. What is important, we have to keep the replica in the way in which we will make the gestures that change its modes of operation.

We have 3 modes of operation at our disposal:

A – ROF setting mode

B - burst setting mode

C - burst and ROF setting mode. In the C mode: a short pull of the trigger = a burst, holding down the trigger = full auto. In case of setting the ful auto on less that 100% - the burst, with the preprogrammed number of shots will be fired, and than the full auto will kick in automatically with the ROF as per set value.

Additionally we can set:

• AB (on/off)
• Precocking
• Cycle completion
• gesture speed (1-4 scale)
• battery voltage warning (the V value set is up to the used)
• battery usage warning (the mAh value set is up to the user)
  
  

Warning! Because of the mechanisms working one cannot set the precocking and cycle completion functions at the same time.

 

The application

Gunfet offers a smartphone application to its device. It not only allows to configure the circuit but also offers a battle mode, which offers the following:

• counting the number of shots fired,
• counting the number of hits vs the number of shots fired,
• marking the number of your won DEATHs and scored FRAGs. When we click the DEATH button the battle is paused, clicking it again resumes the battle. This is used to mark the length of the time spent on the respawn.

Additionally, the purchase of the bluFET allows to register us and the product on the myGUNfet website. This give us the option to save our battles together with GPS data and stats, which can be made available on your profile and the manufacturers website.

User experience

I must admit that operating and configuring the MOSFET from a smartphone is very comfortable. This solution suites me batter than the tactical programming card which is delivered with the GATE's TITAN set. In the XXI century, where almost everyone has a smartphone, such a solution is very practical and comfortable.

In standard modes bluFET does not have access to single only mode, yet by choosing the B mode (burst) and setting its length to 1, the replica fires one shot each time, regardless of the selector position (semi – auto). Unfortunately, enthusiasts of fast single fire will be disappointed as the circuit forces a 100ms delay between individual trigger pulls. The manufacturer says its is necessary for proper operation as the plates in the trigger switch vibrate and it roughly lasts for 60-80ms. The bluFET as a set an external device does not detect the physical position of the selector switch plate and relies on remotely gathered data. If the delay was not there the circuit would not differentiate between a single trigger pull from a constant one and could mistake burst with full auto. Generally, in snipers rifle replicas it wont be a problem but it can disappoint players who wish to use bluFET for a single only for CQB for example. In such a case it may be that a player will pull the trigger faster than a replica will be firing its shots. 

Another limitation the accelerometer imposes on the bluFET design is the necessity to permanently attach it to a replica with wire ties, double-sided duct tape or glue. In some replicas it is problematic e.g. the AR15 family of replicas ith the battery housed in the butt stock guide or other designs with little space for a battery. Yet, knowing this limitation beforehand, one can assess if this product is suitable for his/her need or not.

Additionally, I must point out that the cycle completition feature is not 100% precise. On one hand it is far less precise that optical or mechanicl sensors (such as GATE Titan, ASCU, or ones used in PTW replicas), on the other hand no other circuit mounted outside the gearbox offers this function. I am sure that the users of the above mentioned circuits and PTWs will be somewhat disappointed but I personally think that it is a very interesting solution which, apart from prolonging the life of the spring (as it is decompressed after each shot), it makes the whole gearbox run smoother.

Operating the bluFET with gestures is easy and intuitive if one remembers two simple rules. Firstly, for a gesture to be properly detected, the replica must be positioned +/- 30 degrees along the axis set during calibration. This allows for changing the firing mode only in the ready to fire position and not while the replica is carried on ones back for instance. Secondly, it is worthwhile to practice with the application on to set the speed of the gestures comfortable for a given user, which will allow to change the firing mode during a game.

As fare as the application's functionality and the battle mode go, in unfortunately needs to be constantly paired with the smartphone vie bluetooth (low energy). Additionally, to mark FRAGs or DEATHs one must constantly take the phone out and click on the proper buttons. In my oopinion such features could be implemented using predefined gestures which would convince me to use this application. 

Summary

bluFET MOSFET by GUNfet is a breath of fresh air in the world of electronic circuits meant for airsoft replicas. I am not able to foresee if the solutions proposed by it (especially the application and the website) will catch on in the airsoft community. Yet I do think that programming the circuit via a smartphone is simply very convenient. As fare as robustness of the bluFET is concerned, it seams to be quite good. It was tested for an extended period of time in a replica generating 600 FPS @ 25 RPS, which is normally used only in single fire mode but for the purpose of this test was used also in full auto and burst modes.

Finally, I would like to GUNfet for frequent updates to their application according to the user's feedback. In my case it turned out that bluFET could not be properly configured for gesture recognition when it was mounted vertically. After sending this info an update addressing this issue was available just a few days later.

We would like to thank GUNfet for their help during this test and for making the bluFET available for testing.