Gearbox version SR25 Extrem QSC (CNC, maximum load, material EN AW 7075 T6, 8mm bearings) - RetroArms

CNC gearbox designed for SR25 type airsoft guns, made from a block of the strongest aerospace duralumin EN AW 7075 T651, which has a higher tensile strength (590MPa) than common structural steel (390MPa). Thanks to the material used, the gearbox has a multiple times higher lifespan than a standard zinc-alloy gearbox. We manufacture the Gearbox on precise CNC machining centers, directly in our production facility. The number in parentheses (8mm) indicates the diameter of the hole for the bearings.

Package includes: CNC SR25 gearbox (8mm) - QSC in the selected color variant, a set of screws, and a QSC spring guide.

We have incorporated many useful improvements into the CNC gearbox for SR25:

• Spring retainers have a notch to prevent the feeder arm spring and the trigger slider from falling out.
• Notch for the trigger safety spring, so the spring does not slip out during assembly.
• Notch for the trigger spring, so the spring does not slip out during assembly.
• AOE check window.
• The holes for the bearings have a diameter smaller by -0.02mm (7.98mm), so the bearing does not spin after installation, and the lead edges are chamfered, making installation easier.
• We have enlarged the cable grooves by 1mm, now cables with a cross-section of 2.5mm can be routed without problems.
• We have added a protrusion as protection against cable abrasion from the motor housing.
• All threads are now rolled; compared to cut threads, they have higher strength.
• Both halves of the gearbox are centered by milled protrusions and grooves.
• We have added a hole through which the reverse travel pawl can be released.
• For even greater durability, we have further reinforced a very critical spot on the outer side of the gearbox near the cylinder head, where there is now a large radius and 100% more material in this area.
• We added a notch for the reverse stop spring so it doesn't pop out during assembly.
• The outer edges are machine chamfered.
• On the outside of the gearbox, there is a marking for the diameter of the holes for bearings (8mm or 9mm).

The Gearbox features QSC quick spring change, allowing the spring to be removed by simply turning an Allen key with the spring guide, without needing to disassemble the gearbox. With this solution, it is necessary to secure the spring guide with a screw. For SR25 weapons, this is done by tightening the stock screw. For weapons with, for example, a folding stock, it is necessary to secure the QSC spring guide with a screw. Otherwise, a situation may arise where the spring guide gets stuck in the spring. This is due to the quick spring change; the spring guide is not fixed in the gearbox but is designed to be removable by turning the key.

The space for the trigger contacts is modified to allow the installation and use of standard trigger contacts and processor units from commonly available manufacturers, e.g. Gate etc.

The CNC gearbox for SR25 features a protective anodized finish because thanks to the properties of durability and lightweight design