APC 4 blade propellers offer great scale appearance, and offer better ground clearance.
APC Propeller molds are machined using computer numerically controlled (CNC) milling machines. The CNC commands are generated using a series of propeller performance and structural analysis programs that allow synthesis of propeller shapes in accordance with specified performance characteristics including engine power, RPM, thrust, diameter, pitch, composite material characteristics, and model velocity.
The propeller shapes are defined with mathematical techniques that promote aerodynamically desirable characteristics. Propeller structural loading is determined using empirical NASA wing section lift and drag data. All of this will ensure you get the best propeller possible for your model.
Casting of the propellers is done on state-of-the-art injection molding equipment capable of lengths up to 16 inches, the mold and machine are adjusted during set-up to ensure prop balance is within tolerance. Usually, the user can rely on the APC propeller being balanced and ready for use.