0 • Traxxas
Motors and Gearing
There are two different types of aftermarket motors which can
be purchased for your model, stock and modified. Stock motors
all have the same wire thickness and number of turns around the
armature as governed by sanctioned racing organizations. They
are inexpensive, and widely available. Modified motors are more
expensive, may feature ball bearings and come in a variety of wire
thicknesses and number of turns of wire on the armature. The
fewer number of turns of wire on the armature, the more powerful
the motor will be. Keep in mind that the more powerful the motor,
the less battery run time you will have.
One of the more significant advantages to your model’s transmission
is the extremely wide range of available gear ratios. It can be geared
low enough to run extremely hot, modified motors. Modified
motors should be geared lower (higher numerically) than stock
motors because they reach their maximum power at higher RPM’s. A
modified motor that is geared incorrectly can actually be slower than
a correctly-geared, stock motor. Use the following formula to calculate
the overall ratio for combinations not listed on the gear chart:
If you are worried that you might be over-geared, check the
temperature of the battery pack and motor. If the battery is
extremely hot, and/or the motor is too hot to touch, your model is
probably over-geared. If you are not able to run your model for at
least four minutes before the battery dies, then change to a lower
gear ratio. This temperature test assumes that the model is close to
factory stock weight and operates freely with no excessive friction,
dragging, or binding.
The model is equipped with a Titan 12T 550 motor. The gear
combination that comes stock on each model provides good
overall acceleration and top speed. If you want more top speed
and less acceleration install the included optional large pinion gear
(more teeth). If you want more acceleration and less top speed,
use a smaller optional (not included) pinion gear.
The included
optional large pinion gear is intended for high-speed running on
hard surfaces, and this gearing is not recommended for off-road
or repetitive starting and stopping.
The Titan 12T is equipped with an integrated cooling fan that is
effective during medium to high-speed operation. The gearbox
is specially vented to cool the motor. Repetitive starting and
stopping over short
distances creates
excess heat and will not
allow the fan to cool
the motor properly.
For this type of driving,
smaller pinion gears are
recommended to reduce
load on the motor. See
the guide above.
Centering Your Servo
If the trim controls on your transmitter seem off, you may need to
recenter your servo(s). Additionally, whenever your servo(s) have
been removed for service or cleaning, they must be re-centered
prior to installation in the model.
1. Disconnect the servo horn from the steering servo. On mechanical
speed control (MSC) models, remove the MSC from the throttle
servo as well.
2. Connect the steering servo to channel 1 on the receiver. Connect
the electronic speed control (ESC) to channel 2. The white wire
on the servo lead is positioned towards the crystal. For MSC,
connect the throttle servo to channel 2 and the MSC to “BATT”
on the receiver.
3. Place fresh “AA” batteries in the transmitter and turn the transmitter
power switch on.
4. Turn the throttle and steering trim adjustments on the transmitter
to the center “0” position.
5. Elevate the rear wheels of the model. On MSC models, disconnect
the red motor wire. Connect a fresh 7.2V battery pack to the
speed control and turn on the ESC (see page 15). For models with
MSC, the model will turn on as soon as the battery is connected,
there is no switch. The servo(s) will automatically jump to its
center position.
6. Turn off the power to the model
followed by the transmitter. The servo
horn is now ready to be installed.
7. Be careful not to move the servo shaft
when installing the servo horn (for the
correct orientation and neutral position
of the MSC, refer to illustration).
Readjust the ESC as described in the
“Adjusting the Speed Control” section.
# Spur Gear Teeth
x 2.72 = Final Gear Ratio
# Pinion Gear Teeth
Adjusting Your Model
Spur Gear
P
inion G
ear
76
83
86
90
12
-
-
19.50
20.40
13
-
-
18.01
18.82
14
-
-
16.70
17.49
15
-
15.04
15.58
16.32
16
-
14.12
14.63
15.31
17
-
13.27
13.76
14.39
18
-
12.54
13.00
13.60
19
-
11.89
12.32
12.89
20
-
11.28
11.69
12.24
21
-
15.60
11.14
11.66
22
9.38
10.25
10.63
11.12
23
8.97
9.82
10.17
10.63
24
8.62
9.41
9.74
10.20
25
8.27
9.03
9.36
9.79
26
7.94
8.67
9.00
-
27
7.64
8.35
8.67
-
28
7.37
8.05
8.35
-
29
7.12
7.78
8.08
-
30
6.88
7.53
-
-
31
6.66
7.29
-
-
32
6.47
7.04
-
-
33
6.26
-
-
-
34
6.09
-
-
-
34
5.90
-
-
-
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. Items in black will fit 540
motors only (not Titan 12T).
Rustler
Stampede
• Fast Acceleration
• Short Distances
• Small Tracks
19-Tooth
Pinion*
16-Tooth
Pinion*
• Good Acceleration
• Good Speed
• Normal Conditions
23-Tooth
Pinion
19-Tooth
Pinion
• High Top Speed
• Long Distances
• Hard Surfaces
28-Tooth
Pinion
23-Tooth
Pinion
*optional (sold separately)
Correct MSC Orientation
