is available to the US only at this time.
customers, we are working on a solution.
a Brushless ESC and Motor cool by gearing properly.
To keeping the motor from
overheating must be looked at on both sides, under and over gearing.
don't over gear (tall or high gearing), meaning: If your pinion is too
large and/or your spur gear is too small then it will be over geared.
To get the motor to maintain the desired speed it takes more torque Current.
The motor may not be able reach the desired speed as the batteries and
esc, and the motor windings themselves can only handle so much current
before becoming damaged.
don't under gear (short or low gearing), meaning: If your pinion is too
small and/or your spur gear is too large then it will be under geared.
This means your motor reaches maximum rpm too quickly because of
applying higher Voltage, effectively
placing too small of a load on the motor- running a motor unloaded ( no
real resistance ) can also damage the rotor over time.
by Amps equals Watts,
More Watts equals more Heat.
efficiency plays a huge factor in this. The better the components such
as wire quality, insulation quality, precision windings, bearing
quality, magnet quality.... the more efficient the motor will be.
Better costs more and you get what you pay for.
While there is no 100% efficient motor, there is a huge difference
between a 70% efficient and an 85% efficient motor. If you look at 7.4V
* 50A you get 370W. On the 70% motor 30% turns directly to heat,
111watts. Verses the 15% from the 85% motor for 55.5watts of heat. That
little difference in quality results in a huge 50% difference in
inefficient heat. This much difference is very common between cheap
motors and the quality motors on the market today. Likewise about the
components in the ESC.
There is a lot to consider about
your driving style and terrain.
is not as simple as picking a motor and gearing, it is picking the
right motor and gearing for the conditions. What terrain, what battery,
what driving style? There are other things to consider as well when you
involve aftermarket parts such as tires and wheels of different size
and weight, excessive weight from aftermarket alloy parts, and other
Frequent slowing and stopping with quick acceleration will require more
low-end power or lower gearing. Usually short or technical tracks need
lower gearing. Likewise rougher terrain such as running in grass also
require lower gearing. Care must be taken because you will not have the
higher speed of taller gearing and it is easy to push your truck hard
and over heat your ESC and/or Motor.
Long stretches of track, oval tracks, or open areas will require higher
gearing to get higher speeds. Going too tall on the gearing will over
stress the motor and/or ESC which will cause over heating.
Testing by trial and error is the best way to find optimal gearing.
Everyone drives differently even on the same terrain.
Remember that changing from one style driving and/or terrain to another
will many times require re-gearing to obtain optimal performance.
Also remember that changing to different battery packs (increased
voltage or from NiMH to LiPo) will also many times require re-gearing
for optimal performance. Driving in grass puts a lot of strain on your
motor and ESC no matter what the gearing, don't push it too hard.
What does changing the
Pinion Gear (gear on the motor) do?
changing the Spur Gear or Motor RPM, smaller Pinions (or lower gearing)
will reduce the driving speed and increase torque. Opposite, larger
will increase the speed and decrease the torque.
does changing the Spur Gear (gear on the transmission input shaft) do?
changing the Pinion Gear or Motor RPM, Smaller Spurs will increase the
driving speed and reduce torque. Larger will decrease the speed and
As you can see changing the pinion and spur work in opposite direction
for speed changes.
Remember it is possible to change both the pinion and spur and still
have the same gear ratio. Example 10/25 gearing is equal to 20/50
gearing. Both are a ratio of 2:5
Motors "KV" ratings (rpm per volt) determined by the
number of wire "turns" in the motor.
is not the same thing as "kV" or Kilo-Volt.
The higher the KV rating on a motor the faster it turns with the same
applied voltage as a lower rated motor.
The lower the Turn count the faster the motor turns at the same applied
voltage as a higher count motor.
If your motor is too slow or too fast, you may not be physically able
to find or fit the correct size gears to operate in the optimal range.
Most people use 540 size brushless motors in the 3000KV to 6000KV range
or 6.5 to 13.5 turn. It is possible to use motors out of that range.
speaking, With a Temp gun a warm/hot motor & ESC should be
around 150° to 170° Fahrenheit and under 200° Fahrenheit. Some motors
and ESCs are different depending upon construction, check the
Creations says " As long as the motor is less than 200
degrees F (would burn your finger almost instantly) at the end of the
run, you’re OK."
says "the maximum external safe
operating temperature for Novak brushless motors is 175 degrees F (80
degrees C). Motors that run at higher temperatures have sustained
internal damage. From our testing and experience, keeping the external
motor operating temperature under 160 degrees F (72 degrees C) will
provide the best performance when the car is handling well.
most people don't use a temp gun, here is an easier way to check.
-WARNING- This could be
dangerous, take care in using the following technique. Children should
not use this technique.
You should be able to put your finger on the the can of the motor or
fins of the ESC and not feel pain. This is still subjective since
everyone has a different threshold of pain, I would guess mine to be
average to slightly above average for middle aged people in this hobby.
-doesn't feel any different than before driving.
-You can tell it is warmer than before driving but not much warmer than
- Noticeably different than Cool but you can hold your finger on it for
any length of time.
-You can keep your finger on the motor for a long period of time but it
is not comfortable. This is optimal for general use.
-You can put your finger on it but you need to remove it because it
starts to hurt. You need to consider changes. You are beginning to push
the truck too hard. This is where I try to stop pushing my trucks.
Where I draw the
danger line, you should not run a motor hotter than this or about 200
-You can touch your finger to it but need to remove it quickly because
you it is very uncomfortable and would become painful very quickly,
your instinct is to pull your hand back. This is where thermal
breakdown becomes destructive to your electronics and you should take
action to prevent more heat. Shut your stuff off, let it cool, and find
a solution. There IS a Problem even if it is you expecting too much out
of the truck.
-You can barely touch it and your feel immediate pain, your immediate
instinct is to pull your hand back.
NEVER let your motor get this hot!
Super Freaking HOT!!!
-Severe pain and you have to remove your finger immediately and
blisters form, your instinct doesn't matter because your natural
reaction caused every muscle in your arm to contract to pull your hand
to safety. At this point, you've probably severely damaged something
and your motor & ESC are likely damaged too.
is my opinion and approach to keep the ESC and Motor cool by gearing