Retro Arms CNC Gearbox V2 8mm QSC

SKU 29466
  • CNC gearbox V2 designed for airsoft replicas AR15 (M4), M16.This gearbox is manufactured from one solid block of aircraft aluminium (Dural) EN AW 7075 T651, which has higher strength (590MPa), than common construction steel (390MPa). Because of this material, Retro Arms gearboxes have better durability and resilience than common zinc-aluminum gearboxes.

Retro Arms have made some useful improvements for their V2 CNC gearboxes:

  • Detail in bracket (8mm) means diameter for bushings/bearings.

  • Spring holders have grooves, so the springs for tapped plate and trigger switch will not jump off.

  • Groove for safety lever, so it will hold during installation.

  • Groove for trigger spring, for better fitting.

  • AOE control hole.

  • Sockets for bushings/bearings have smaller diameter about -0,02mm (7,98mm), to prevent overturning of the bushings during installation. The socket edges are cut down for better installation.

  • Enhanced grooves for wiring for 1mm, you can now use wiring with 2,5mm diameter.

  • Protecting edge for wiring against the motor.

  • All threads are now shaped instead of cut for better strength.

  • Both of the gearbox parts are centered by milled grooves and edges.

  • Added hole for releasing anti-reverse latch.

  • For better durability, more material has been added around the cylinder head part of the gearbox.

  • Added groove for anti-reversal latch spring, so it will not jump off.

  • Outer edges are now cut off.

RetroArms gearbox has quick spring change system QSC, where you can put out whole spring guide with hex key and change the spring without needing to open the gearbox. In this solution, you need to secure spring guide with screw, commonly with AR 15 (M4) replicas, it is by stock screw. In situations where you have folding stocks or no stock at all, you have to secure the spring guide with QSC screw. Otherwise there could be situation, where the spring guide will stuck with the spring. This is because the spring guide is not fixed in the gearbox but has will for easy removing with hex key.

Space for trigger switch is designed for compatibility with trigger switches, trigger units from common manufacturers for example: Gate, etc.


  • CNC gearbox V2 has protective anodizing.
  • CNC gearbox can be installed only in airsoft replicas with Tokyo Marui compatible standard. That means even the inner parts. Do not use force during installation. Use only 1Nm tightening on screws, otherwise the screws will overturn. 
  • This CNC Gearbox is compatible with any spring, but stronger springs may result in 
  • !! do not use MAXX cylinder head !!
  • Installation of the inner parts and gearbox requires professional knowledge, experience and skills. There are a lot of airsoft manufacturers on the market and every one of them create their own sizes, there are no standards like engineering ISO in airsoft


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