Retro Arms Airsoft CNC SR25 8mm Gearbox Shell

CNC Gearbox SR-25 (8mm) – QSC

CNC gearbox designed for airsoft SR-25 replicas from A&K, P&J, Classic Army, and G&P. 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 used material, our gearboxes have the best durability and resilience than common zinc-aluminium gearboxes. We are manufacturing these gearboxes on our precise CNC milling machines in our factory.

Package includes CNC Gearbox SR-25 (8mm), set of screws and QSC spring guide.

We made some useful improvements into our SR-25 CNC gearboxes:

Spring holders have grooves, so the springs for tappet plate and main switch will not jump off.

Added groove for safety lever, so it will hold during installation.

Added groove for main switch spring, for better fitting.

AOE control hole.

Sockets for bushings/bearings have smaller diameter about -0,02mm (7,98mm), for non-overturning the bushings during installation.

We enhanced grooves for wiring for 1mm, you can now use wirings with 2,5mm diameter.

Added protecting edge for wiring against the motor.

Both gearbox parts are centred by milled grooves and edges.

Added hole for releasing anti-reverse latch.

For better durability, we added more material around cylinder head part of the gearbox, this was the most critical part and we added 100% more material where huge radius is.

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

Outer edges are now chamfered.

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

The gearbox has protective anodize coating, The reason for this is that there is a risk of corrosion (huge grey spots that look terrible).

! do not use MAXX cylinder head !!

Do not use too much force during installation. Use only 1Nm tightening torque on screws, otherwise the screws will overturn in heads. There is no need of tightening screws with too much force, if you want to be sure that screws will not loosen, use thread locker.

Retro Arms gearboxes have a quick spring change system QSC, where you can remove the spring guide with hex key and change the spring without need of opening the gearbox.

Please be aware due to the QSC system you need to make sure the stock screw is installed before operating the gearbox as this centres the spring guide. Failure to do so could damage your internal parts.

You can use in our CNC gearbox any spring of your choice but be aware that stronger springs will result in lower durability.

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. This is the main problem with a lot of inner and outer parts from different manufacturers which can be same product, but with different dimensions.

Same Day Dispatch on All Orders Placed Before 3pm Monday – Friday

For Airsoft Use Only, cannot be Adapted or Modified for any other purpose

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