Master Airscrew 3.1:1 for S400 RC Aircraft Gearbox - MAS3431

The Master Airscrew 3431 gearbox is a 3.1:1 reduction unit built for S400-size motors in electric RC aircraft. It steps the motor speed down through a 3.1:1 gear ratio, letting you swing a larger, slower-turning propeller for more efficient thrust on lightweight park flyers and electric models. If you're running an S400 motor and want to convert it from a direct-drive setup to a geared one, this is the gearbox to do it. The MAS3431 is a direct replacement and upgrade part for builders who want better propeller matching from their existing S400 power system.

Key Features

• 3.1:1 gear reduction ratio for slower prop speed and larger propeller swing
• Designed specifically to mount and drive S400-size brushed motors
• Converts a direct-drive S400 setup into a geared propulsion system
• Suited to lightweight electric RC aircraft and park flyers
• Master Airscrew construction for consistent, reliable gear engagement

Compatible With

• S400 Motor

What's Included

• Master Airscrew 3431 3.1:1 gearbox for S400 motors