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One of the
benefits of brushless motors is that they require very little
maintenance, but they should be inspected regularly and cleaned
to provide optimum performance. This article details the steps
you should take to keep your motor in tiptop shape. I also
provide tips on how to make your motor run cooler. A Novak Super
Sport speed control and SS4300 motor are shown here, but the
information also applies to most of the rebuildable brushless
motors on the market.
1.Clean the
chassis & speed control
Use an air
compressor to blow off the dust and dirt that has accumulated on
the chassis and speed control. It’s best to work with a clean
car and work space to prevent crud from getting into the motor.
If necessary, use an old toothbrush to remove stubborn dirt
deposits.
After you’ve finished
cleaning the chassis, make sure that the speed control isn’t
loose. If you can wiggle it easily, remove it and the
double-sided tape it’s attached with, and reinstall it with
fresh tape.
2. Inspect the
wiring
Check the speed control
for frayed wires and damaged insulation; these can lead to radio
interference and, worse, short- circuiting, which can burn up the
motor and speed control. Repair damaged wires with heat-shrink tubing
or liquid electrical tape
Use heat-shrink
tubing or liquid electrical tape to repair damaged wire insulation.
3. Remove the motor
You do not need to
unsolder the motor’s power leads or unplug the sensor harness, but
doing so will give you more freedom to work. After removing the motor,
wipe it with a rag to remove dust and dirt.
Wipe the motor
thoroughly with a rag. Use a toothbrush to clean the ball bearings.
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Keep
it cool
 With
today’s high-capacity NiMH and LiPo cells, run times longer
than 30 minutes are not unusual. But running a vehicle that
long can lead to overheating that will cause your speed
control’s thermal-shutdown feature to kick in. Fortunately,
Novak sells a couple of products that will keep your Novak
brushless motor system running cool during extended run times.
Check with your motor’s manufacturer because they probably
have optional motor-cooling products as well.
Attach Novak’s 25x25x10mm cooling fan to your Super Sport
brushless speed control, and it will pass a constant flow of
cool air over the motor heat sinks. The fan can be attached to
the heat sink with 440 screws. Simply thread the screws
between the fins on the heat sink and plug the fan’s
connector into you receiver’s battery slot; it can also be
wired to the speed control. The fan uses very little power, so
it will not decrease your run times.
Novak’s Velociti motor sleeve replaces the stock center
sleeve in your Velociti or Super Sport brushless motor, and it
has tall cooling fins to dissipate heat. This motor sleeve
will not fit most 1⁄10-scale off-road buggies and trucks
in which the transmission wraps around the motor. It’s best
for on-road vehicles and monster trucks with a lot of room
above the motor. The fins are designed to have a fan mounted
directly to the heat sink as well.
Installing both of these items will significantly lower the
running temperature of your motor and speed control. If you
use batteries with a capacity of 4800mAh or more, these items
are must-haves.
25x25x10mm cooling fan—item no. 5647; $13.79
Velociti motor sleeve—5413 (black), 5414 (purple), 5415 (blue);
$18.39
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4. Disassemble the motor
Brushless motors
have very few parts, so it’s easy to take them apart for
cleaning. Most are held together by a few screws on the front,
back, or sides of the motor case. Remove the screws, disassemble
the motor and lay the parts on a clean rag. Be sure you don’t
lose any spacers or washers that are used to properly align the
motor shaft (and magnets) inside the motor. Also note the order in
which the spacers or washers are installed.
It is a
good idea to put the rotor into a plastic bag to keep it
clean. Any metallic bits that the rotor attracts will be
removed with the bag.
5. Clean
the motor
Just as with
regular brushed motors, dirt can accumulate inside a brushless
motor. We do not recommend the use of motor spray to clean the
windings inside the motor can (stator). Racers who use motor spray
simply make any problems worse. Instead, use a small brush and
light air pressure to clean inside the motor.
Use a small
brush and compressed air to clean the inside of the motor.
6. Clean the
bearings
Remove the rear
bearing from the motor for cleaning. The front bearing on Novak
brushless motors is glued to the front endbell and cannot be
removed; leave the front bearing in place, and give it a good
dousing with motor spray.
Douse the
bearings with motor spray, and then put them aside to dry.
7. Inspect the
motor
Check the clean
disassembled motor pieces for signs of wear. Make sure that the
windings in the can aren’t loose, chafed, or shiny. Check the
magnets for rub marks, and make sure they aren’t chipped or
loose.
Inspect the
major components for signs of wear. A loose winding or a
damaged magnet means that your motor needs factory service.
8. Lubricate the
bearings
The motor spray
washed away the factory-applied lubricant, so you’ll need to
relubricate the bearings.
When the
cleaned bearings have dried, apply a light bearing lubricant.
9. Inspect the
bearings
Before you rebuild
the motor, check the front and rear ball bearings to ensure that
they spin freely. Insert the tip of a pencil into the bearing and
use it to rotate the inner race. If the bearing feels gritty,
replace it. Check your motor’s instructions, or consult its
manufacturer to make sure that you get a replacement of the proper
size.
Insert a
pencil point into the bearing, and spin the inner race. It
should spin smoothly. Replace damaged bearings before you
rebuild the motor.
10. Rebuild the
motor
You have cleaned
and inspected the motor’s major components and lubed the
bearings, and it’s now time to rebuild it.
Tighten the
screws evenly.
11. Reinstall
the motor
Make sure that the
gear mesh is set correctly, and use zip-ties to secure the power
leads and the sensor wires and to keep them away from spinning
parts. Your brushless system is now ready for action.
Bolt the
motor back onto its mount, and secure the wires with zip-ties
to prevent them from touching any moving parts.
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