Cnc piston for short stroke 12t retroarms (ra-9422)

RETRO ARMS BRAND

CNC-machined piston
Material: nylon GF30%
For short stroke 12T configurations
Weight: 12g

A specially extended, reinforced, and significantly lightened piston designed for short-stroke setups with up to 12 teeth.
The piston is optimized for Retro Arms gearboxes but can also be used in standard gearboxes.
Before final installation, it is necessary to check whether the piston can be fully cocked by the 12-tooth sector gear.

This piston differs from standard models because it has a longer body while maintaining regular guide dimensions, ensuring less leverage during the piston's short stroke.

The rear section is significantly reinforced to withstand the stresses caused by strong springs in TSG, DSG, and SSG setups (forces up to 19 kg) combined with rapid load changes due to high fire rates, often reaching up to 60 RPS.
This combination of speed and stress, along with the usual forces acting on standard pistons, is what causes the rear part of the piston to break, ejecting the piston rack into the back of the gearbox.

The piston's body is CNC-milled from nylon with 30% glass fiber reinforcement.
This material offers excellent properties, including wear resistance, tolerance to high temperatures and pressures, high resistance to aggressive oils and impacts, while also being very lightweight.
The nylon material used is oil-resistant, and while it is not necessary to lubricate the piston's guide grooves, we have integrated lubrication pockets at the contact points between the piston and the gearbox.

Despite its robust and extended structure, the weight has been kept low, which is essential for high-speed builds, at only 16.0 g.
We do not recommend enlarging the vent holes to avoid potential structural damage.
The piston's weight may vary due to moisture absorption of the material. However, we strongly advise against drying the piston, as moisture absorption significantly enhances its strength.

The piston rack is made from high-quality spring steel through CNC machining.
The material is flexible yet, thanks to heat treatment, also hard and wear-resistant.
Although gluing the piston rack is unnecessary, some customers choose to do so (in that case, we recommend a two-component epoxy adhesive).
For this reason, the racks are left untreated (without an oil-based surface treatment) after heat treatment, resulting in a dark gray color with possible colored stains.
It is recommended to lubricate the piston rack before installation, ideally with silicone grease.

This piston has 19 teeth and is therefore suitable for use with Pandora SS12T gears (8055 or 8059).