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Electric motors aren’t very complex, and now that you know the basics, the
knowledge can be applied to all of the motors on the market, helping you make
better purchasing decisions, understand your current motor’s workings, and get
the most out of your gear. ✇
When brushed motor tech was the standard, it was common for motors to be rebuildable, so you could extend
their life. Today, the brushed
motors in ready-to-run vehicles are typically considered
to be consumable—when
your motor wears out, you
just buy a new one. Irony time:
Nearly all brushless motors are
rebuildable, but with no brushes to replace or commutator
to wear out, there’s rarely a reason to disassemble them.
Heat reduces motor performance, which is why many motors have ribbed or finned cans
to help with cooling. Motors in larger, heavier models are often cooled by accessory fans,
and may use deeply finned sleeves to provide more cooling area. If your vehicle has a
fan-cooled motor, be sure the fan is plugged in and operating to keep temps in check.
Keeping your motor cool is a great way to get the most power and torque out of it as well
as ensuring its durability.
KV AND TURNS
A motor’s “Kv” rating refers to its rpm in thousands (K)
per volt of electricity (v). For example, a 1000Kv motor will
spin at 1,000rpm when hooked up to a 1-volt power supply. If you attach a 7-volt battery, it will spin at 7,000rpm.
Some brands do not list Kv but instead indicate the
motor’s “turns,” such as “ 17.5T.” This refers to the number
of times the wire inside the motor is wrapped around the
stator—each wrap is a “turn.” The fewer the number of
turns, the higher the motor’s rpm. When choosing a
motor, keep in mind that a higher-rpm motor may not
necessarily make your car faster. Heavier vehicles, such
as monster trucks, require more torque, and the motor
that makes it go fastest may not necessarily be the one
with the highest rpm.
Brushless motors can
be rebuilt—but you’ll
probably never need to.
When it comes to electric motor
performance, cooler is better.