E-Revo • 25
MOTORS AND GEARING
The Titan
™
550 Motors on your E-Revo have been carefully designed to
match the needs of the E-Revo. The Titans are made to run efficiently
at high voltage to provide more torque and longer run times. We
do not recommend converting the E-Revo to a typical low-voltage
setup using traditional 540 size motors. While these components will
physically fit into the E-Revo, the system will not run as efficiently,
losing power in the form of motor and battery heating. The result
will be shorter run times, high current draw, and extreme battery and
motor temperatures.
The E-Revo is equipped from the factory with a 68-tooth spur gear and
19-tooth pinion gears. E-Revo has a large range of gearing making it
suitable for many different types of applications and environments. If
you want more acceleration and less top speed, use a smaller pinion
gear (fewer teeth, higher numerical ratio). The overall reduction is
the number of turns the motor makes for one revolution of the tire.
Higher numerical ratios provide more torque, lower numerical ratios
provide more top speed.
With the Titan motors, do not use a pinion
gear larger than 20-tooth with the stock 68-tooth spur gear with
6-cell battery packs or a pinion gear larger than 19-tooth with the
stock 68-tooth spur gear when using 7-cell battery packs.
Use the
following formula to calculate the overall ratio for combinations not
listed on the gear chart:
Motor Configuration
The E-Revo uses an innovative, opposed motor mounting system
for the Titan
™
motors. To optimize efficiency and performance,
the front and rear motors on the E-Revo are not the same
. Their
opposed mounting system requires special attention to correct
motor installation.
If you remove the motors for cleaning or service, always be sure to
install them in the correct location on the model. The motor with the
“Reverse Rotation” label (#3975R) will always install to the front of the
model. This motor is also identified by having longer motor wires.
The second motor (#3975) will always mount to the rear of the model.
• If the motors are installed incorrectly, the model will run backward.
Reversing the motor wires if installed incorrectly is not
recommended
, as this will reduce efficiency, performance, and
cause premature motor failure.
• Using two of the same part number
motors in not recommended. Only use
the correct motors in E-Revo. Be sure
they are installed in the correct locations
(#3975R in the front location, #3975 in
the rear location).
If you are considering replacing the
motor with aftermarket motors, look for
550 motors capable of 12 or more volts
with 0˚ timing. If motors with internal
timing are used, the front motor must
have equal, but “reverse” timing of
the rear motor. See page 31 for more
information on motor replacement.
Adjusting Gear Mesh
Incorrect gear mesh is the most common
cause of stripped spur gears. Gear mesh
should be checked and adjusted anytime
a gear is replaced. Access the gears by
removing the single screw on the top
gear cover.
To set the gear mesh, cut a narrow strip of
notebook paper and run it into the gear
mesh of the front motor. The front motor
is held in place with two motor screws.
Loosen the motor screws and slide the
motor and pinion gear into the spur gear.
Retighten the motor screws and then
remove the strip of paper. You should be
able to run a fresh strip of paper through
the gears without binding them.
Next, run the strip of notebook paper into
the gear mesh of the rear motor. The rear
motor is mounted to an aluminum motor
mount. Loosen the single motor mount
screw with the provided 3mm wrench to
slide the motor mount. Slide the motor
and pinion gear into the spur gear.
Retighten the motor mount screw and
then remove the strip of paper. You should be able to run a fresh
strip of paper through the gears without binding them.
# Spur Gear Teeth
x 5.22 = Final Gear Ratio
# Pinion Gear Teeth
Gearing Compatibility Chart:
The chart below shows a full range
of gear combinations. This does NOT
imply that these gear combinations
should be used. Over-gearing
(bigger pinions, smaller spurs) can
overheat and damage the motor
and/or speed control.
Stock factory gearing
Not for 14-cell
battery running
Not recommended
Spur Gear
Pinion Gear
62
65
68
12
-
-
29.57
13
-
-
27.29
14
-
24.23
25.34
15
-
22.61
23.65
16
-
21.20
22.18
17
19.03
19.95
20.87
18
17.97
18.84
19.71
19
-
17.85
18.67
20
-
-
17.74
21
-
-
-
22
-
-
-
BASIC TUNING ADJUSTMENTS
Front
of Truck
Front
Location
Reversed
Motor
Rear
Location
Standard
Motor
Rear Motor
Mount Screw
Do Not Loosen
Front Motor Screws
