Inner structure of motor
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Motor Base
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Stator
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Wires (windings)
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Bearing
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Magnets
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Motor Bell
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Shaft
Bearing
Popular used are Japanese Brand NSK, NMB, EZO etc
Width
Height
Stator
Brushless motors are typically categorized by a four-digit number – such as 2207.
22 numbers are the stator width and 07 is the stator height.
Configuration
For example "12N14P"
N means the number of stator “wire wound”poles
P means the number of rotor “permanent magnet” poles
Wire
If a voltage is applied to a copper wire, a current will flow, which will induce a magnetic field. With a permanent magnet near this current-carrying copper wire it is possible to generate linear or rotational forces to the wire and the magnet.
KV
The magnets are rotated from one stator pole to the next. More poles (P) and (N) = shorter the distance between these two sections. This leads to a slower spinning motor and therefore a lower KV rating. More copper & resistance, increase manetic field, thus high torque.
It is the theoretical increase of motor rpm (rotation per minute)
1900KV motors with a 6S LiPo battery (25.2V), the motor would turn at 478800 rpm. (1900 x 25.2V) without load.
Higher KV motors would turn the propeller quicker with less torque, and lower KV motors create higher torque with less rotation. Bigger props are matched with low KV motors, and smaller props with high KV motors.
Arc Magnets
Curved magnets bring the magnets closer to the stator; allows for a smaller and consistent gap which makes the motor more powerful, improves torque and response.
Magnets graded according to their magnetic field strength, such as N50, N52, N54 etc. The higher the number, the stronger the magnetic field.
Motor Base
Mounting patterns (hole distance in diagonal).
Use too long screws may damage the motor's wire.
Shaft
Use to mount a propeller
different size and material
Bell
Common use aluminium for lightweight and durability.
