Master Airscrew 3-Blade 7x4 RC Propeller - Reverse/Pusher CW (178mm, 11.1g)

This Master Airscrew 3-blade 7x4 propeller is engineered for RC airplane applications that require a reverse or pusher configuration with clockwise rotation. With a 7-inch diameter and 4-inch pitch, it measures 178 mm by 102 mm respectively. The lightweight design at just 11.1 grams reduces rotational inertia, helping motors spool up quickly. It is built from a glass-fiber reinforced composite material that offers a good balance of stiffness and impact resistance. This propeller is suitable for both electric motors and internal combustion engines (glow or gas).

What adapter rings are included?

The propeller comes with a set of adapter rings to fit various motor shaft diameters. Included sizes are: 1/8 inch (3.175 mm), 3/16 inch (4.7625 mm), 5/16 inch (7.9375 mm), 4 mm, 5 mm, and 6 mm. This allows the propeller to be mounted on motors with shafts ranging from about 3 mm to 8 mm.

Key specifications

Design and construction

Master Airscrew has been producing model airplane propellers for over 45 years, and this 3-blade design continues that tradition. The blades are molded from glass-fiber reinforced composite, a material chosen for its consistency and ability to hold shape under load. A 3-blade propeller offers a different aesthetic and can help clear shorter landing gear compared to a 2-blade. The reverse/pusher rotation is marked clearly, and the adapter rings allow a custom fit on a wide range of motor shafts.

Compatibility and use

This propeller is intended for use on RC airplanes. It works with electric motors as well as gas and glow engines. Because it is a pusher/reverse rotation propeller, it is often used on twin-engine models where one motor must spin opposite to the other, or on pusher aircraft where the propeller is mounted behind the wing. The clockwise (CW) direction as viewed from the front of the aircraft is standard for many pusher configurations. Always verify the rotation direction matches your motor's required direction before installation.

Frequently asked questions

How do I determine the direction of rotation?

The propeller is labeled as reverse/pusher/CW. When looking at the propeller from the front of the aircraft (the direction of flight), a CW propeller rotates clockwise. For reverse rotation, it typically means the propeller is pushing air instead of pulling. Ensure your motor is set to rotate in the correct direction using your transmitter or speed controller.

Can I use this propeller on a multirotor?

This product is specifically for RC airplanes, not multirotors. The design and blade profile are optimized for airplane applications.

What is the maximum RPM rating?

The supplied information does not specify a maximum RPM. It is recommended to start conservatively and monitor the propeller for any signs of stress, especially with high-power setups.

Does it come with a balanced collet?

The propeller includes only the adapter rings. No collet or mounting hardware is included beyond those rings.

Master Airscrew manufactures this propeller in California, USA. It is available in various sizes and both CW and CCW versions. This specific model is the 7x4 reverse/pusher CW variant.