Traxxas 56076-1 User Manual
Page 25
SUMMIT • 25
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
For two 6- or 7-cell NiMH
batteries and 4S LiPo batteries
Not recommended
Spur Gear
Pinion Gear
62
65
68
12
26.96
28.26
29.57
13
24.89
26.09
27.29
14
23.11
24.23
25.34
15
21.57
22.61
23.65
16
20.22
21.20
22.18
17
19.03
19.95
20.87
18
17.97
18.84
19.71
Spur Gear
Pinion Gear
62
65
68
12
74.66
78.27
81.88
13
68.91
72.25
75.58
14
63.99
67.09
70.18
15
59.73
62.62
65.51
16
55.99
58.70
61.41
17
52.70
55.25
57.80
18
49.77
52.18
54.59
High Gear
Low Gear
model (listed in your parts list). Experimentation with different
types of tires is recommended to see which ones work the best on
the terrain where the model is run. When selecting tires, consider
the overall diameter and the rubber compound (hard or soft). If
the overall diameter of the tire is significantly increased, you will
need to use a smaller pinion gear to compensate for the larger tire.
Soft compound tires with many short spikes generally work better
on hard, dry surfaces. In loose dirt, a tire with large spikes should
perform better. See your parts list for accessory wheels and tires.
MOTORS AND GEARING
The Summit’s Titan
™
775 Motor has been carefully designed to
match the needs of the Summit. The Titan is made to run efficiently
at high voltage to provide more torque and longer run times. We
do not recommend converting the Summit to a typical low-voltage
setup using traditional 540 size motors. While these components
will physically fit into the Summit, 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 Summit is equipped from the factory with a 68-tooth spur gear
and 14-tooth pinion gear. Summit 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 775
motor, do not use a pinion gear larger than 14-tooth with the
stock 68-tooth spur gear. Use the following formula to calculate
the overall ratio for combinations not listed on the gear chart:
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 motor. The 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.
Motor Installation
To access the motor, remove the gear
cover by removing the single screw on
the top of the gear cover. The motor
uses an aluminum mount for quick, easy
motor access and gearing adjustment.
To remove the motor, remove the single
large hex screw using the supplied 3mm
wrench. Then, rotate the motor and
mount to the side of the model and slide backward off the post.
In addition to the 4mm holes used to mount the Summit’s Titan
775 motor, the motor plate has additional holes that accept
standard 540 motors (or other motors that use 3mm screws
and 25mm mounting hole spacing). There are two sets of holes
provided for 540 motors. They are:
1. Low CG (center of gravity) installation (mounts the motor low to
the chassis for best handling performance)
2. High CG installation (mounts motor higher for more clearance
for larger motors or aftermarket heat sinks)
TUNING ADJUSTMENTS
To find High Gear :
# Spur Gear Teeth
x 5.22 =
Final
Gear Ratio
# Pinion Gear Teeth
To find Low Gear :
# Spur Gear Teeth
x 14.45 =
Final
Gear Ratio
# Pinion Gear Teeth
Motor Mount
Screw
Do Not Loosen