[RETRO ARMS] CNC gearbox V2 DSG, TSG (8mm) - QSC

This is a V2 gearbox designed specifically for special gears that cock twice per rotation, such as DSG (Dual Sector Gear) or TSG (Triple Sector Gear).

This gearbox shortens the cylinder by the amount of capacity not used for short-stroking,
and in turn, extends the piston rail to suppress uneven wear of the piston rail.
The package includes a dedicated stainless steel cylinder with a total length of 52mm.

Added on 2026.4.10

The inner diameter of the included dedicated cylinder is microscopically slightly larger, so even with regular electric gun O-rings, airtightness may not be achieved depending on manufacturing tolerances. For this reason, we have decided to include a dedicated O-ring with a microscopically slightly larger outer diameter. The O-ring material is FKM-70, which is fluorine-based. Please do not use fluorine-based grease as it may cause swelling.

If you wish to use a different cylinder, please shorten a standard electric gun cylinder to 52mm in total length and install it.

The piston stroke supports up to 9 teeth.
Standard single sector gears can also be used if they have up to 9 teeth.

This gearbox is designed from the outset for electronic triggers (compatible with various manufacturers such as Jefftron, GATE, Shiranui Shoten, etc.),
and is not compatible with mechanical switches that use a cut-off lever, so caution is required.

The 2025 version is compatible with our company's CNC Lateral adjustment of gearbox alignment, which allows for gearbox left/right alignment adjustment.
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↑The bearing rail shown above is sold separately.

Furthermore, this gearbox features a guide bearing positioned at the top,
supporting the upper part of the piston to prevent the piston rail from strongly rubbing against the gearbox side,
and reducing resistance during retraction to improve cycle speed as much as possible.

Due to the presence of this guide bearing, when lightening the piston by skeletonizing it,
avoid drilling holes on the top surface of the piston.
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The wiring guard under the motor tower/pinion gear is still in place.
It pairs perfectly with electronic trigger wiring routing.
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Common precautions for all gearbox versions
Please use a cylinder head that fits snugly against the gearbox, as shown in the image above.
For example, G&G genuine cylinder heads cannot be used as they leave a gap.

If there is even a slight gap, the piston impact will be absorbed by the anti-rotation protrusions on both sides, leading to damage.
Ideally, the cylinder head should fit snugly against the gearbox with enough clearance to allow for a slight backward movement.
For the same reason, do not use cylinder heads with O-rings or rubber dampers on the contact surface with the gearbox.

The shaft hole size is Φ8mm H7 (0 to +15μm). Please choose between press-fitting or adhesive bonding depending on the bearing used.
When using anaerobic adhesive for bonding, note that the gearbox is anodized and in an inactive state.
If the bearing side is also stainless steel, an inactive metal, the adhesive is highly likely not to cure.
Please use an activator for inactive metals.

The bearing holes are equipped with anti-rotation protrusions, making them compatible with our CNC ANTIROT bushings 3mm.