Motor/Gearing - Traxxas E-Maxx Brushless Edition 3908L Owner's Manual

MOTOR AND GEARING
The E-Maxx is equipped from the factory with a 68-tooth spur gear
and 17-tooth pinion gears. E-Maxx 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. Use the following
formula to calculate the overall ratio for combinations not listed on
the gear chart:
# Spur Gear Teeth
x 5.22 = Final Gear Ratio
# Pinion Gear Teeth
Caution! Operating your model with 65+mph gearing
• The 28/65 ratio for use with 6S LiPo batteries is designed
#5608 E-Revo
25+mph 25+mph
35+mph 35+mph
Brushless Edition
for maximum speed on smooth surfaces only, with steady
Pinion/Spur 18/65 18/65 18/65 18/65
acceleration to full throttle and optional Talon tires installed.
twin 6-Cell NiMH twin 7-Cell NiMH
Battery
Battery
• Do not use this gear ratio for general driving.
(12 cell total) (14 cell total)
Nominal Voltage Nominal Voltage 14.4V 16.8V
• Avoid repetitive starting and stopping.
mAh mAh 3000+ mAh 4000+ mAh
• Do not use the 28/65 ratio with NiMH batteries or low-capacity
Skill Level Skill Level
LiPo batteries. 5000mAh LiPo batteries are recommended.
• Allow the motor to cool between runs, and monitor motor
temperature.
* With Included Optional Gearing
** 24T pinion not included. Optional gearing for high-speed running on smooth surfaces only.
• Do not use the 28/65 gear ratio for off-road running or
overheating and damage may result.
#3908 E-Maxx
#3908 E-Maxx
25+mph 28+mph
35+mph 35+mph
28+mph 25+mph 35+mph 35+mph
Brushless Edition
Brushless Edition
Pinion/Spur
18/65 17/68 18/65 17/68
Pinion/Spur
17/68 18/65 18/65 17/68
twin 6-Cell NiMH twin 7-Cell NiMH
Battery
Battery twin 6-Cell NiMH twin 7-Cell NiMH
Battery
Battery
(12 cell total) (14 cell total)
(12 cell total) (14 cell total)
Nominal Voltage Nominal Voltage 14.4V 16.8V
Nominal Voltage Nominal Voltage 14.4V 16.8V
3000+ mAh 3000+ mAh
mAh mAh
3000+ mAh 3000+ mAh
mAh mAh
Skill Level Skill Level
Skill Level Skill Level
* With Included Optional Gearing
** 28T pinion and 65T spur not included. Optional gearing for high-speed running on smooth surfaces with optional Talon tires only.
• Do not allow the motor temperature to exceed 200° F or damage
and motor failure may result.
To accurately monitor motor temperature, Traxxas suggests the
#4091 On-Board Temperature Gauge. The gauge features a large
LCD screen, on/off button for longer battery life, a min/max temp
button, a Centigrade/Fahrenheit button, and a clear Lexan splash
guard. Visit your local dealer or Traxxas.com for more information.
Adjusting Gear Mesh
Incorrect gear mesh is the most
common cause of stripped spur
gears. Gear mesh should be
checked and adjusted anytime
Your Battery Selection and Pinion Gear
a gear is replaced. Access the
Selection Determines Your Speed.
How Fast Do You Want To Go?
gears by removing the single
screw on the top gear cover.
65mph
* *
40+mph 50+mph
& Beyond
To set the gear mesh, cut a
18/54 18/65 24/54 ** **
narrow strip of notebook paper
twin 2S LiPo twin 3S LiPo twin 3S LiPo
and run it into the gear mesh.
(4S total) (6S total) (6S total)
Loosen the motor screws and
14.8V 22.2V 22.2V
slide a motor and pinion gear
5000+ mAh 5000+ mAh 5000+ mAh
into the spur gear. Retighten the
motor screws and then remove
the strip of paper. Repeat with
the other motor. You should
be able to run a fresh strip of
paper through the gears without
binding them.
Your Battery Selection and Pinion Gear Your Battery Selection and Pinion Gear
Selection Determines Your Speed.
Selection Determines Your Speed.
How Fast Do You Want To Go?
How Fast Do You Want To Go?
65mph
65mph
40+mph * * 50+mph
40+mph * * 50+mph
& Beyond
& Beyond
20/68 17/68 28/65 ** **
20/68 17/68 28/65 ** **
twin 2S LiPo twin 3S LiPo twin 3S LiPo
twin 2S LiPo twin 3S LiPo twin 3S LiPo
(4S total) (6S total) (6S total)
(4S total) (6S total) (6S total)
14.8V 22.2V 22.2V
14.8V 22.2V 22.2V
5000+ mAh 5000+ mAh 5000+ mAh
5000+ mAh 5000+ mAh 5000+ mAh
TUNING ADJUSTMENTS
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.
Motor
Screw
Strip of
Paper
B
B
Spur Gear
65 68
15 DNF 4.53
16 DNF 4.25
17 4.00
DNF
18 3.78
DNF
19 3.42 3.58
20 3.40
3.25
21 3.10 3.24
22 NR 3.09
23 NR DNF
24 NR DNF
Stock gearing
Optional included gearing (4S LiPo)
Recommended gearing
for all battery types
Recommended gearing
for 4S LiPo only
Not recommended
Does not fit
E-MAXX BRUSHLESS • 23