[RETRO ARMS] CNC Split Gearbox V2 (8mm) - QSC 2025

Dramatically improved strength and precision compared to the original zinc gearbox
The combined weight of the screws and spring guide is approximately 178g, which also contributes to weight reduction.
In addition, each part is reinforced with thick walls for structural strength.

This product is different from the conventional Ver.2 gearbox in that it has an upper intake and exhaust section and a lower drive section.
It has a two-part structure, which improves maintenance and customization.

The 2025 version has been updated with the following improvements:

-Improved cylinder holding method
・Improved piston rail
- Added a window to check the piston position
・Retro Arms CNC Antirot bushings 3mm compatible
・Retro Arms CNC Lateral adjustment of gearbox alignment
・Wiring route expansion
・Increased tappet plate advance
- Tappet plate guide added

*Note*

The structure has changed and is not compatible with previous versions.

As with normal gearboxes, a variety of chambers are available.
Basically, the top and bottom are connected with a standard AR-15 takedown pin.
By adjusting the connection method, it can also be used with other Ver.2 models such as the G3 series and MP5 series.

The spring has a quick change structure using a special spring guide.
It can be easily adjusted by simply replacing it from the rear.
----------------------------------------------------------------------------------------------


One change from the previous version is that part of the tappet plate guide has been moved to the lower side.
Therefore, please be aware that thick, multi-layered electronic triggers may interfere.
The Leviathan-V2 OPTICAL can be installed without interference with the front and rear wiring.
----------------------------------------------------------------------------------------------


The cylinder holding system has been expanded to six points, three at the front and three at the back, making it compatible with cylinders from a wider range of manufacturers.
----------------------------------------------------------------------------------------------


The wiring space, which was a problem with Ver.2, has been enlarged, and a thick cord with a maximum finished outer diameter of Φ3.5 mm can be used.
Since it is designed to allow for easy passage, it is ideal for high-load use such as high-cycle tuning.

Furthermore, the wiring is hidden under a unique wiring guard under the pinion.
The pinion gear no longer damages the wiring. It is designed to allow the signal wire of the electronic trigger to pass through.
The ease of incorporating an electronic trigger is also outstanding.
----------------------------------------------------------------------------------------------


Common precautions for all gearbox versions
Be sure to use a cylinder head that fits tightly against the gearbox, as shown in the image above.
For example, the G&G genuine cylinder head cannot be used because it creates gaps.

If there is even a small gap, the piston impact will be received by the rotation stopper protrusions on the left and right, causing damage.
Ideally, it should fit snugly against the gearbox, with enough clearance to move slightly backwards.
For the same reason, cylinder heads with O-rings or rubber dampers on the contact surface with the gearbox are also used.
Never use it.

The shaft hole size is Φ8mm H7 (0 to +15μm). Use press-fit or adhesive depending on the bearing you are using.
When using anaerobic adhesives for bonding, the gearbox side is anodized and inert.
If the bearing side is also stainless steel, which is an inert metal, there is a high possibility that the adhesive will not harden.
Use an activator for inert metals.

The bearing hole is equipped with a rotation prevention protrusion, so the company's CNC ANTIROT bushings 3mm
It is compatible with.