APC Propellers

APC propellers are made from composite materials and are available in a range of sizes starting from 4-inch diameters to 27-inch diameters. The majority of APC propellers are made of fiberglass composite, while others are manufactured with carbon fiber and polycarbonate. The carbon fiber propellers have the letter C in the part number. Polycarbonate propellers have the letters BD at the beginning of the part number. These props are incredibly resistant to breakage and are popular in quad-copter racing and freestyle applications.

This repository contains data on the next categories of APC props:

1.    For internal combustion engines;
2.    For electric motors;
3.    For multi-copters/ drones;
4.    For marine.

The nomenclature used for APC propellers helps identify the size and type of each propeller. The size of each propeller is designated by two numbers that are stamped onto the propeller blade, separated by an X. The first number represents the diameter of the propeller in inches. The second number is the pitch in inches per revolution.

APC propellers are by default assumed to be of a standard type (Sport) unless modified for a specific characteristic or purpose. Sport propellers are intended for use with internal combustion engines. The letter(s) following and/or preceding the propeller size indicates the type and/or modification. The letter(s) that precede the propeller size in the part number are identified below. The various propeller types and modifiers are described as follows:

Type:

E  - Thin Electric or Electric (electric only)

F  -  Folding Blade (electric only)

MR - Multi-Rotor (electric only)

SF - Slow Flyer (electric only)

R  - Reversible ESC (electric only)

Modifier:

B  - Black Color (precedes diameter in part number)

B4  - Bundle Pack (2CW and 2 CCW propellers)

D  -  Durable Material (precedes diameter in part number)

W  -  Wide (chord)

N  - Narrow (chord)

NN -  Very Narrow (chord)

PN -  Pattern

P  -  Pusher (or reverse rotation for electrics)

ST -  Self Tightening

C  -   Carbon Material (40% Carbon / 60% Nylon by weight)

T   -   T-Mount

( )  -  Reserved for Special Notes

A combination of the above may be used. For example: MRP is a reverse rotation multi-rotor propeller.

If there are no letters behind the propeller size, then it is a standard rotation Sport propeller. Although sport propellers are intended for use with internal combustion engines, they can also be used with electric motors. Electric propellers are intended for use with electric motors only.

The following are suggested RPM limits for each propeller type:

• Glow Engine (includes Sport and Pattern Propellers) and Speed 400 Electric (E) Propellers

                      Maximum RPM=190,000/prop diameter (inches).

                      For example, a 10×6 glow engine prop should be limited to 19,000 RPM000

• Thin Electric (E) Propellers and Polycarbonate (Durable) FPV Propellers

Maximum RPM=150,000/prop diameter (inches)

• Folding Electric (F) Propellers

Maximum RPM=120,000/prop diameter (inches)

• Multi-Rotor (MR) Propellers and Multi-Rotor Folding (MRF) Propellers

Maximum RPM=105,000/prop diameter (inches)

• Slow Flyer (SF) Propellers

Maximum RPM=65,000/prop diameter (inches)

• Racing Propellers (including Carbon) and Electric Carbon (EC) Propellers 8.75 N, W and 8.8 Series 40 Pylon Props Sport Propellers (for IC Engines) on Electric Motors

Maximum RPM=225,000/prop diameter (inches)

• Racing Propellers (including Carbon) on Electric Motors 8.75 N,W and 8.8 Series 40 Pylon Props on Electric Motors

Maximum RPM=270,000/prop diameter (inches)

Optimum RPM represent engine RPM's that draw 100 watts under static (zero aircraft velocity) conditions. These data reflect computed predictions, NOT test measurements. These predictions have been compared with 74 test cases and the computed means agree rather well. However, the scatter about the mean is generally on the order of about 10%.

There are different types of propeller installation. Several Multi-Rotor propeller sizes are available with a self-tightening feature. These propellers include a M6x1 hex nut that fits into the hub. A right-hand (RH) thread is used for MR propellers and a left-hand (LH) thread is used for MRP (reverse rotation) propellers. With the exception of the hub design, the blades are identical to the standard MR version propellers.

There is also a new line of folding propellers and hubs specifically designed for multi-rotor applications. The patented hub allows for quick blade removal without the use of any tools. The hub is designed to attach to the motor bell housing with two M3 screws, spaced 12mm apart. The 4mm center hole can be used for centering the hub or attaching to a motor shaft.

The propeller blades can be either removed or folded, allowing for more compact packaging. A hub without the quick-release feature is also available for systems that use active rotor braking.

Reference

https://www.apcprop.com/

https://www.apcprop.com/wp-content/uploads/2023/05/APC-Propeller-Nomenclature.pdf