APC AP205205E CW Contra Drive Propeller 20.5x20.5E for F3A Pattern  [AP205205E]

Pattern aircraft propeller notes

The APC AP205205E propeller is a 20.5x20.5E contra-drive blade machined for clockwise rotation and intended for F3A pattern applications. The passage below outlines mounting checks, recommended installation practice, and expected effects on trim and throttle control.

Fitment: confirm motor shaft diameter and spinner or prop adapter type before installation. Contra drive props require matching mounting hardware and correct thread or collet sizing to secure the blade set to the motor shaft.

Installation notes: ensure correct rotation direction for CW contra setup, tighten hub hardware evenly, and verify clearances to airframe surfaces and control linkages. Balance the propeller assembly dynamically or statically as part of final setup to reduce vibration transmitted to the airframe and electronics.

Tuning role: a 20.5x20.5 profile affects static thrust and pitch behaviour; use incremental changes in pitch and motor timing (on your ESC) to refine vertical response and slow-speed precision during pattern maneuvers.

As a replacement or upgrade for pattern machines that require a 20.5x20.5 contra drive CW set, this prop delivers predictable performance when correct fit, rotation and balancing procedures are followed.