RC Toy Propeller Selection

Propeller selection
Differences in propellers can drastically change flight characteristics, even if nothing else on the craft changes. Changes in pitch or length can adjust thrust but will also adjust the amount of strain on the powerplant. A prop with more blades creates more thrust if the prop turns at the same speed.
Some tips for propeller selection:
If a plane's cowl is low to the ground during takeoff or landing (short or no landing gear), a shorter prop with more blades can replace a longer prop and provide equal thrust.
The more air the prop moves, the more thrust is provided. A prop with a steeper pitch and/or wider blade will displace more air at the same speed. The more air displaced in each rotation, the more responsive the craft is in regard to its relative weight. 3D flyers require more air displacement in order to support the weight of the craft. A narrow prop with high pitch that may be used for racing can displace a lot of air at high RPMs but may not create enough displacement per rotation to be used for a higher drag bi-plane of the same wingspan.
If a prop is too long and/or too heavy, it can create a gyro effect which will counteract yaw and pitch and make the craft less responsive. A little gyro effect can be beneficial for stability, so this needs to be determined on a craft by craft basis.
i have brought some APC propeller from Swanghobby.com

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