Traxxas VXL-3s Instructions page 2

• Mount the speed control where you will have easy access to the plugs
and the on/off (EZ-Set) button without having to remove the body.
• Mount the speed control so that none of the power components (wiring,
motor, ESC) contacts any part of the radio system, particularly the
antenna wire. The receiver should be mounted so the antenna wire can
be extended as far away from the speed control as possible. The antenna
wire should be extended vertically in the mast and not wrapped on the
chassis under the body. Excess antenna wire should not be coiled on
the chassis. Servo cables and the antenna wire should not cross or come
in contact with any of the motor or battery wires. These steps will help
reduce the possibility of radio interference.
• Graphite or metal chassis have been known to transmit radio noise
generated by the motor. If the receiver is to be mounted on the chassis,
position it so the crystal and antenna are as far away from the chassis as
possible. This may require you to mount the receiver on its side. This will
reduce the chance of picking up radio interference from the motor.
VXL-3s Wiring
The VXL-3s electronic speed control is capable of controlling brushed,
brushless, and sensored brushless motors. The VXL-3s auto-detects the
motor type and has numerous built-in safeguards to prevent damage from
miswiring or damaged wiring.
Sensorless brushless motors
Sensorless motors are the easiest and most reliable brushless motor type.
The VXL-3s is optimized to deliver the smoothest possible sensorless motor
performance. The Velineon 3500 is a sensorless brushless motor. The wiring
(phase alignment) of the motor determines its direction of rotation. Refer to
the wiring diagram below.
Sensored brushless motors
The VXL-3s is fully compatible with sensored brushless motors. Sensor
motors use an additional sensor installed in the motor to communicate
rotor position to the speed control. The VXL-3s features a covered auxiliary
port that accepts aftermarket motor sensors on the front face of the unit.
The VXL-3s has built-in Sensor Motor Backup Protection to prevent damage
if the sensor leads or phase leads become disconnected. If a sensor lead
becomes damaged or is disconnected, the VXL-3s automatically switches to
sensorless brushless operation.
The VXL-3s also features Sensor Phase Detection. When a sensored
brushless motor is connected, the VXL-3s will check for proper wiring. If
the motor phase wiring is incorrect, the VXL-3s will not apply power to the
motor until it is wired correctly.
Brushed motors
For the ultimate in versatility, the VXL-3s has no motor limit when used
with a brushed motor. This allows you to use any readily available 540 or
550 size brushed motors in your VXL-3s equipped vehicle. Always be sure
to follow all break in and maintenance instructions set forth by the motor
manufacturer. The VXL-3s automatically detects what kind of motor it is
connected to so no programming actions are required to use brushed
motors. Simply be sure to properly connect the motor to the speed control
as shown.
• Motor positive (+) should be connected to phase A (blue).
• Phase B is not used.
• Motor negative (-) should be connected to phase C (white).
If the wiring is reversed, the motor will operate in reverse. If the motor is
wired incorrectly (using phases A+B or B+C), the VXL-3s will send short
pulses to the motor and turn off the LED indicating a fail safe mode. It will
not return to normal operation until wired properly.
Transmitter Setup
Traxxas TQ Radio Systems
Before attempting to program your VXL-3s, it is important to make sure
your TQ transmitter is properly adjusted (set back to the factory defaults).
Otherwise, you may not get the best performance from your speed control.
The transmitter should be adjusted as follows:
1. Set the throttle neutral switch to the 50/50 setting. This adjusts the
transmitter's throttle trigger throw to 50% for throttle and 50% for
braking and reverse. Experienced users may wish to use the 70/30
setting if more broad proportional control is desired in forward than with
braking and reverse. This might be desirable in a racing environment
where reverse is disabled.
2. Set the throttle trim control to the middle 0 setting.
3. Set the Channel 2 servo reversing switch to the left position. Do
not change the position of any of the servo reversing switches after
programming the VXL-3s.
4. You are now ready to program your speed control.
Aftermarket (Non-Traxxas) Transmitters
The following instructions are provided as a general reference only for
those who are using non-Traxxas transmitters. Consult your transmitter's
instructions for information on how to change the settings.
1. Set the High ATV (adjustable travel volume) or EPA (end point
adjustment) to the maximum setting. This is the amount of servo throw
at full throttle.
2. Set the Low ATV, EPA or ATL (low side only trim adjustment) to the
maximum setting. This is the amount of servo throw at full brakes
or reverse.
3. Set the throttle trim to the middle (neutral setting).
4. Set the throttle channel reversing switch to either position. Do not
change the switch position after programming.
5. Set the trigger throw adjustment to 50% throttle and 50% brake (either
mechanical or electronic).
6. Set the exponential setting (if equipped) to the zero or fully linear setting.
Aftermarket Receivers
The VXL-3s is compatible with most aftermarket
receivers. By removing the tab on the edge of the power
connector, the VXL-3s can be plugged directly into some
models of Futaba® , Airtronics® , Hitec® , and JR® receivers.
Please refer to the manufacturer's wiring diagrams that
came with your receiver. On the VXL-3s, the red wire is positive, the black
wire is negative, and the white wire is the control wire. Warning: On some
older Airtronics® radio systems, the positive and negative terminals are
opposite of the VXL-3s and an adapter is required. Crossing the red (+)
and black (-) wires could damage the receiver and the VXL-3s. Study the
manufacturer's wiring diagrams closely, or consult your hobby dealer.
Low-Voltage Detection Setting
The Velineon VXL-3s electronic speed control is equipped with built-in Low-
Voltage Detection. The Low Voltage Detection circuitry constantly monitors
the battery voltage. When the battery voltage begins to reach the minimum
recommended discharge voltage threshold for LiPo battery packs, the VXL-3s
will limit the power output to 50% throttle. When the battery voltage attempts
to fall below the minimum threshold, the VXL-3s will shut down all motor
output. The LED on the speed control will slowly blink red, indicating a low
voltage shutdown. The VXL-3s will stay in this mode until a fully charged battery
is connected.
The electronic speed control is factory set with Low-Voltage Detection activated.
Low-Voltage Detection should be disabled when using NiMH batteries.
use LiPo batteries while Low-Voltage Detection is disabled.
Verify that Low-Voltage Detection is activated:
1. Turn on the transmitter (with the throttle at neutral).
2. Connect a fully charged battery pack to the VXL-3s.
3. Press and release the EZ-Set button to turn the VXL-3s on. If the LED is solid
green, then Low-Voltage Detection is ACTIVATED). If the LED is solid red,
then the Low-Voltage Detection is DISABLED (not safe to use LiPo batteries).
Never