Gearboxes Specna Arms

This most common material is most often found in basic weapons. Its great advantage is its low production cost, but its overall durability is not at the same level as CNC duralumin, which is why there are limitations on the spring for these types – this depends on the specific version of the gearbox, but also on the manufacturer. These gearboxes are manufactured by pouring a molten zinc-aluminum mixture into a mold, which is then allowed to cool. Therefore, with castings, especially in version 2 gearboxes (Ar15, Mp5, etc.), it is not a question of whether it will break, but when it will break. Most often, these gearboxes can handle M120 springs in the long term. These gearboxes are especially suitable for weapons where high performance is not a priority. Here, it is sufficient to seal the air system well, shim the wheels, and, if necessary, replace the classic trigger contacts with, for example, a processor. Today, we most often encounter their reinforced variants.

Suitable for: undemanding constructions, weaker springs, basic weapons

    

Reinforced gearboxes

In these types of gearboxes, the most stressed parts, such as the front part of the cylinder, have been reinforced. From our experience, we can recommend the manufacturer Specna Arms, which started putting these gearboxes in PRIME edition weapons.

Suitable for: stronger springs, speed builds, replacement for the original gearbox

    

CNC dural gearboxes

In airsoft, a CNC gearbox is a highly sophisticated upgrade. These gearboxes are usually manufactured by CNC machining from aluminum alloys such as EN AW 7075 T651, which is known for its high strength and durability. The result is a gearbox with very precise dimensions. This improves compatibility with internal parts from different manufacturers and can also facilitate installation and tuning. Although these gearboxes are more expensive than cast versions, a big advantage is that they are very light and designed for long-term durability even with extremely strong springs or high-speed assemblies. So buying a CNC gearbox will definitely pay off in the future. We definitely recommend CNC gearboxes! Here we can unequivocally recommend products from Retro Arms.
Suitable for: DMR, strong springs, high-speed builds, builds with maximum durability

     

What does QD gearbox mean?

Gearboxes marked as QD allow for quick spring replacement by turning a special QD spring pin. This system will definitely come in handy when we need to reduce or increase spring stiffness (but then it will probably be necessary to readjust the hop-up and zero the collimator). The best option is to combine this gearbox with the body of the weapon, so that it is not necessary to remove the gearbox from the body of the weapon each time. But here, too, we must keep in mind the words compatibility and correct centering of the gearbox in the body.

                                      

Our tip:
When choosing a replica with a QD spring replacement, you can quickly and conveniently respond to the various limitations of different playing fields. With a well-chosen replica length, it is a truly versatile weapon that you can use for CQB as well as a DMR in the forest!

How should I choose a gearbox?  

Weapon type
The main criterion is the type of weapon (AK, AR15, special weapons) in which we will install the gearbox. There are a number of gearbox versions, depending on the weapons in which a given type fits. These gearbox versions are labeled V2, V3, etc. (we discuss the individual gearbox versions at the end of the article).

Usage / requirements
Next is the intended use (strong springs/weaker performance, etc.), which is also related to the durability of the gearboxes, which we have already discussed. 

Our capabilities / experience
Last but not least, a lot depends on your experience with upgrades. Not every gearbox will fit into every body on the first try, and the same applies to the internal parts installed in the gearbox. For use with HPA systems, versions without bearing holes have been produced, which are specifically designed for use with various HPA systems. We recommend checking compatibility with your system.

Is it a good idea to purchase a pre-assembled gearbox?  

This option is ideal for those who plan to make a minor upgrade or repair, or want to replace a broken gearbox with a new one and do not need to use the original internal parts, but are unsure about the correct selection of individual components. A complete gearbox from the manufacturer ensures functionality and, if using a body from the same manufacturer, a very quick replacement for the original gearbox. 
But be careful, guns have different nozzle lengths. In practice, this may mean that the replica may not seal properly or may not feed the BBs into the chamber properly. Therefore, if you are considering a full upgrade, it is best to have the gearbox assembled by an experienced technician who will select the right parts for your gun.

Our advice: before installing the gearbox into the body, it is necessary to check its compatibility. In case of an error, there is a risk of damage to parts or unreliable functionality of the weapon. If you are unsure about the installation, we recommend entrusting your weapon to our professional service department. 

Gearbox version 2, gearbox version 3, what does that actually mean?

Many new players, but also professionals, mistakenly believe that the term "version" refers to progress in the development of the gearbox, and therefore assume that gearbox version 7 is objectively better and stronger than version 2. Simply put, the difference between versions of airsoft gearboxes is basically in the shape of the skeleton, which varies so that the gearbox fits into different gun bodies. 

Mechaboxes for different types of weapons will differ in internal parts such as the switch slide, trigger, cylinder head, and nozzle, but at the same time they have the same type of mechabox skeleton, gears, cylinder, and piston. Below, we will introduce the most common types of mechaboxes for airsoft electric weapons, list some of their features, and what distinguishes them from others. 

Mechabox versions in individual weapon types 

    
Mechabox V2

Mechabox version 2 is, alongside version 3, one of the most common mechaboxes today. Mechabox version 2 is typically found in M4/AR15, SMG-5, MP5, and other types of weapons. Over the years, the basic mechabox version 2 has been supplemented with many improvements by various manufacturers, such as an AOE window, a window for releasing the recoil latch, pre-formed radii, a protrusion for cable routing in the motor wheel area, etc. Nowadays, it is common to find mechaboxes equipped with quick spring replacement systems, known as QD mechaboxes. 

Mechabox V2.5

The extended version 2 gearbox can be found in AEGs from Classic Army and A&K in SR25 weapons. This gearbox is identical to version 2 in all respects except for the length of the cylinder and piston, which are extended to provide additional air for the longer inner barrels used in these DMR-style rifles. Another difference is the gears, which have 19 teeth.

Mechabox V3

The version 3 gearbox is another type commonly found in AK47/74, AUG, G36, RPK, and similar weapons. Although all these weapons use the version 3 gearbox, the nozzle, trigger, selector lever, and motor cage type differ depending on the weapon type.
Gears, pistons, and other small parts are mostly compatible between versions 2 and 3. In general, V3 gearboxes are much stronger than V2 gearboxes due to their design and can withstand stronger springs in the long term – except for CNC or reinforced versions, of course.

Mechabox version 4 

This mechabox is found in the Toyko Marui PSG-1 model. This mechabox is unique in its type and uses a longer piston to provide additional air for the extremely long inner barrel of the PSG-1. It did not catch on commercially.

Mechabox Version 5

The Mechabox Version 5 was found inside the Toyko Marui Uzi model, which has long been discontinued. This mechabox is significantly smaller than the others and has a polymer skeleton. It is also the predecessor of the AEP mechabox – electric pistol. 

 

Tokio Marui Standard:
Tokyo Marui is a Japanese company that was one of the first to start manufacturing airsoft guns. At the same time, the design of their parts became a contractual standard, which most manufacturers follow for maximum compatibility – the TM Standard.

Mechabox Version 6

To this day, this mechabox is typically found in the P90, Thompson, and other atypical weapons. Its design was intended for use in unconventionally shaped weapons, where the motor is in a cage and is also compatible with standard version 2/3 wheels and pistons, although it requires its own nozzle and special cylinder head, which differ in design depending on the weapon used. 

Version 7 Gearbox

Version 7 gearboxes are found in M14 AEG rifles, although there are two different versions. The original Tokyo Marui M14, as well as the Cyma M14 rifle, uses newly designed gears. Mechaboxes Version 7, found inside the M14 EBR, use a different motor cage than the standard Version 7 in order to change the angle of the motor and adapt it to the EBR stock.

Mechabox Version 8

The Version 8 mechabox is used in the Toyko Marui Type 89 AEG and allows for 3-round burst firing, which is possible thanks to the 4-position fire selector switch instead of the usual three. It is similar in appearance to Version 2, but has a larger lower section and, like the Version 2 gearbox, uses a motor without a cage. 

 

Mechabox NGRS/Version 9

Version 9, more commonly referred to as Tokyo Marui NGRS, is a more advanced design with a recoil imitation system, a functional safety catch, and improved internal components for a jump in performance. This version is used in the Tokyo Marui M4 NGRS and TM416 Delta series. 

AEP Gearbox

AEP gearboxes are essentially miniature gearboxes that function in the same way as their adult counterparts, but unlike them, they have a tiny piston, cylinder, and three small gears. This gearbox is not compatible with any classic parts for classic large gearboxes. 

Gearboxes for machine guns

Gearboxes for machine guns come in various forms and are usually heavily reinforced gearboxes optimized for fully automatic firing. They can be found in M60, M240, PKM machine guns and most AEG M249s. These versions of gearboxes are generally compatible with standard wheels, pistons and cylinders of version 2/3 and use standard AEG motors. Their main disadvantage is the inability to fire in SEMI mode. These gearboxes are capable of using stronger springs and are also designed for a higher rate of fire than standard gearbox versions.