Electric Flight Motor Terms
Before going in to detail, it’s important to understand all the common terms and values assosiated with motors
KV – The KV value given to motors represents how many revolutions of the motor shaft will occur per volt. A higher value is typical for lower cell count where a lower KV value is typical for higher cell counts. The KV value depends on the wind configuration, motor size and number of winds.
Max. Continuous Current – The Maximum continuous current value assigned to each motor represents the maximum allowable current in amps that can be drawn from the motor continuously. The Max. peak current, will be higher.
Physical Size – The size of the motor generally is proportional to power output. A larger can size will output more power than a smaller can size.
To select the motor best suited for a plane it is important to know the plane size in terms of wingspan, airframe type and amount of cells planned to be used. Size of the plane and the airframe type will determine the size of motor needed to fly the plane effectively. Cell count will determine the wind (Kv) of motor needed.
Inrunner Motor – An inrunner motor provides higher KV values for it’s relative size. Higher KV values are more suited for faster flying planes. The inner rotor which contains the magnets rotates while the stator or windings on the can are stationary.
Outrunner Motor – An outrunner motor provides a lower KV, higher torque quantities which make it effective for many planes. The outer motor can contains the magnets which rotate around the windings or stator.
Motor Selection
Slow fly planes need a power system that has a lower loaded RPM range while Aerobatic Sport planes need a higher loaded RPM range. Therefore, 2 motor selection ranges will be provided
Slower Flight Speeds
2 Cell LiPo 1200KV – 2400KV
3 Cell LiPo 800KV – 1600KV
4 Cell LiPo 600KV – 1250KV
5 Cell LiPo 500KV – 1000KV
6 Cell LiPo 400KV – 850KV
7 Cell LiPo 350KV – 700KV
8 Cell LiPo 300KV – 600KV
9 Cell LiPo 270KV – 550KV
10 Cell LiPo 240KV – 480KV
12 Cell LiPo 200KV – 400KV
Higher Flight Speeds
2 Cell LiPo 2400KV – 4500KV
3 Cell LiPo 1600KV – 3000KV
4 Cell LiPo 1200KV – 2220KV
5 Cell LiPo 970KV – 1850KV
6 Cell LiPo 800KV – 1500KV
7 Cell LiPo 700KV – 1280KV
8 Cell LiPo 600KV – 1120KV
9 Cell LiPo 530KV – 1000KV
10 Cell LiPo 480KV – 900KV
12 Cell LiPo 400KV – 750KV
These charts will accomodate most setups and provide a good base line, however some setups may fall outside of this range. If for any reason you are unsure on how to approach this, please ask questions in the RC Info Forum