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Airsoft internal parts

number of products: 781 products

Internal parts of airsoft replicas - AEG gearbox principle

The heart of any electrical replica is the gearbox, which conceals the mechanism responsible for its operation. Through appropriately selected parts you can increase power, speed or accuracy. It is therefore worth knowing which role the individual components play.

Gearbox frame

The gearbox frame is a casing that hides the internal components of the replica. The numbers V1 - V8 indicate its shape. They were introduced in 1991 by one of the first AEG manufacturers - Tokyo Marui. The most common GB shapes are V2 in the AR15 and Mp5 family, as well as V3 for AK, G36, SIG or AUG. Introduction of a quick spring change system, which not only facilitates service work but also allows to change the power of the replica during the shooter itself, is a more and more often appreciated innovation.

Cylinder sets

Cylinder set is a pneumatic system, which is responsible for proper air compression. It is composed of:

  • cylinder,
  • cylinder head,
  • nozzle, pusher,
  • piston
  • piston head.

Cylinders differ from each other in the coating material and location of the opening (type 0, 1, 2 or 3). Selection principle is simple. The shorter the barrel, the less air it needs. For long barrels type 0 is most appropriate, while for short ones - type 3. The nozzle is designed to supply air from the cylinder to the HU chamber and balls from the magazine to the HU chamber. It moves on a pusher. Its shape and length must be precisely matched to the HU chamber and the HU band. A nozzle that is too long will cause problems with feeding the balls, and a nozzle that is too short will not seal properly. The piston, piston head and cylinder are designed to compress air inside it.

Toothed gears

Gears, piston and gearbox frame are the most critical points of the replica. The role of the gears is to retract the piston of the replica and then let it go so that, driven by the force of the spring, it expands the air in the cylinder. When tuning, it is worth replacing the gears with those made of better materials and adjusting their ratio to the expected rate of fire (ROF). During the installation of new gears it is necessary to pay attention to their proper "shimming" in bearings.


The hardness and number of coils of the spring corresponds to the power of the replica. The spring markings for airsoft are assigned the speed which is reached by a 0.2 gram ball fired from the replica. M100 is 100 m/s, or 330 FPS. M120 is 120m/s, or 400 FPS. Please note that the amount of FPS is dependent on many factors and the markings should be treated only as guidelines.

The internal parts for replicas allow you to improve the performance of your models so that you can enjoy greater efficiency during the game. It is worth remembering that when tuning, it is important to have the appropriate knowledge and experience in this regard. If you are not sure of your own skills, it is worthwhile to call on the help of specialised service centres.


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