Biela propellers

All Biela propellers are manufactured with the use of carbon fiber as the main material. All propellers that are larger than 30 inches and all turbo-propellers are additionally reinforced with Kevlar roving.

Propellers marked with "D" have an increased pitch in the hub area (by approx. 1 - 2 inches), which improves their efficiency, reduces noise, and improves motor cooling, especially when flying 3D.

Propellers are reinforced in the area in the center of the mounting hole with a piece of hardwood. All propellers are equipped with a central hole. Propellers up to 20 inches have an 8mm bore and those from 21 inches have a 10mm bore.

Propellers are available as two- three- four- and fifth-blade.

Two-blade propellers

Biela two-blade propellers are made from carbon fiber. They are factory-balanced and certified up to 8.000 rpm (over 36'' up to 6.000 rpm). These propellers are lightweight and very stiff with a low level of noise. The center (mounting) part is reinforced with a wooden block.

Biela two-blade propellers are available as:

1. Standard;
2. Biela-sport;
3. Semiscale;
4. Wilga;
5. Electro;
6. Push-propeller.

The props of Biela-Sport type are developed with laminar airfoil of the prop blades, similar to the EX-Racing series, but with blade shape more similar to the D type props. The efficiency is around 10 % better compared to the standard version, also there is a better motor cooling at lower speeds (e. g. torque rolls).

Three-blade propellers

Biela three-blade propellers are made from carbon fiber. They are factory-balanced and certified up to 8.000 rpm (over 36'' up to 6.000 rpm). These propellers are lightweight and very stiff with a low level of noise. The center (mounting) part is reinforced with a wooden block.

Biela three-blade propellers are available as:

1. Standard;
2. Biela-sport;
3. Semiscale-Electro;
4. Semiscale;
5. EX-racing;
6. Push-propeller.

The props of Biela-Sport type are developed with laminar airfoil of the prop blades, similar to the EX-Racing series, but with blade shape more similar to the D type props. The efficiency is around 10 % better compared to the standard version, also there is a better motor cooling at lower speeds (e. g. torque rolls).

The props of Semiscale-Electro type are developed for model planes with electric drive. The small hub thickness (16 mm) and optimized weight combined with high efficiency are making this prop type special.

EX-Racing is a series of Biela Propellers with very high efficiency. Optimized blade profile and low profile thickness allowed to significantly reduce aerodynamic resistance.

Four-blade propellers

Biela four-blade propellers are made from carbon fiber. They are factory-balanced and certified to not exceed 8000 rpm. Those propellers are lightweight and very stiff with a low level of noise. The center (mounting) part is reinforced with a wooden block.

Biela four-blade propellers are available as:

1. Semiscale
2. Semiscale-Electro

The props of Semiscale-Electro type are developed for model planes with electric drive. The small hub thickness (16 mm) and optimized weight combined with high efficiency are making this prop type special.

Fifth-blade propellers

Biela fifth-blade propellers are made from carbon fiber. They are factory-balanced and certified to not exceed 9000 rpm. Those propellers are lightweight and very stiff with a low level of noise. The center (mounting) part is reinforced with a wooden block. They are specially developed for Pilatus 21 with K45PT, SPT 5 turbine or 80-100cm³ piston engines.

Reference

https://www.pp-rc.de/biela.htm?shop=pp-rc_en&SessionId=&a=catalog&p=33