Best Propellers to Use for RCGF Engines

by Pat Roy

So what is the best propeller to use - wood, carbon fiber, ? This is one of the more popular questions we get!

For any given plane and engine combination, there will be a propeller that will work best for the type of flying desired. 3d, IMAC, and scale flying each require a different type of propeller response, while each airframe engine combination exert their own influences. Rarely will you find two propellers exactly the same, and blade lengths, pitches, widths, tip shapes, and flexibility vary widely between brands and composition types. "Size" covers a lot of territory with propellers.

The word "typically" will be used quite a bit here because the descriptions that follow are not hard and fast rules, but a generalization.

Wood blades typically "spool" up faster because they are generally lighter than other types. The downside is they can be more flexible and therefore less efficient. A laminated wood prop diverges from the lighter, more flexible description though. They generally are more rigid and are heavier than a comparable propeller cut from one piece of wood.

Carbon composite props are typically more rigid and have more consistent design and mold accuracy while frequently generating more rpm than a wood prop due to blade design and rigidity. Propeller weight increases when carbon composites are used.

Fiberglass composite propellers are typically very "mold accurate", but are slightly more flexible than carbon composite propellers. Propeller weight can be quite light for the size. Generally they are not as desirable for larger displacement engines. Fiberglass propellers are limited in available sizes because of safety concerns when used with large gas engines. Drilling fiberglass propeller hubs for multi bolt engine hubs can create safety issues for larger gassers.

Unfortunately there is no "best" propeller type. Nor is there a "best" propeller that someone could ask for to provide the perfect performance for "their" particular plane. There will always be some variance due to fators induced by the person that assembled the plane. Final weights, engine choice, and desired flying style can make the prop you want or need differ from what works best for a person flying the same plane right next to you.