Losi LOSB0102 - Manual (Page 19)

TM
Battery Position: This is a critical adjustment that is often
overlooked but can be very useful. Start by running the battery
spaced in the middle (standard setup with 6-cell battery pack).
Moving the battery back can improve rear traction on slippery
surfaces and steering response. Moving the battery back too
far can cause the rear end to swing through turns on some
tracks and “dump” the rear end causing instability issues. This
is a result of having the weight too far back. The Desert Truck
comes equipped with two foam battery spacers to split the
difference when adjusting the battery position, hence offering
a middle position when either extreme is inadequate.
Camber Rise Relationship: The Desert Truck setup out of the
box comes with less front camber gain than the rear camber
gain. The reason for this is that less front camber lets the front
end drive flatter and makes the Desert Truck more stable. By
having more camber gain in the rear, the Desert Truck has more
rear traction, this helps the rear tires accelerate through the
bumps and ruts.
Wheels and Tires
The tires come pre-mounted with the vehicle and should be
checked to make certain they stay glued to the wheels. The
wheel spinning speeds can pull the rubber tire away from the
rim. When a tire or tires come loose from the rim you will notice
the vehicle is hard to control.
Tip the vehicle on its side and using both hands to hold one
wheel at a time, use your thumb to press the tire away from
the rim. If you see a tire pull away for the rim use Losi Tire Glue
(LOSA7880 thick or LOSA7881 thin) to re-glue. It only takes a
small drop of glue generally. Be careful this is CA-type glue and
you do not want to glue your fingers to the wheel and tire.
Use safety goggles when gluing tires.
Check the mounting of the tire periodically to ensure proper
performance and handling.
Steering Assembly: Occasionally, check the steering assembly
and you may notice increased looseness. There are several
components which will wear out from use: tie rod ends
(part LOSA6074), the servo saver (part LOSA1610), the bell
crank bushings (part LOSA1620), and the Drag link ball ends
(LOSA6074). You can easily replace these components to restore
factory specifications.
Note: The bell crank bushings may be replaced with
ball bearings (part LOSA6912).
Adjusting Gear Mesh
Incorrect gear mesh is the most common cause of stripped spur
gears. To set the gear mesh, one method is to cut a narrow strip
of notebook paper and thread it in between the gears. 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. Or you can loosen the motor and carefully slide
the motor leaving a small amount of backlash (play) between
the spur and pinion gears. It should not be tight and if you look
up-close there should be slight movement of the spur before
contacting the teeth on the pinion gear.
Gear Ratio
Changing the gearing provides you a quick and easy way
to tune the Desert Truck. Use the temperatures of both the
motor and your battery pack as a guide to gearing to your
environment. When the Motor is above 160-170 degrees
Fahrenheit or the batteries are above 125-135 degrees
Fahrenheit, these are both strong indications that you should
drop the pinion size smaller. This would be a lower gear ratio
or larger number, for example from 11.25 to 12.40. Going up
a pinion size is called gearing higher or a small number, for
example 11.25 to 10.6, and will increase power consumption
and allow more speed.
Use the following formula to calculate the overall ratio for
combinations not listed on the gear chart:
Spur Gear Size
Pinion Gear Size
X 2.43 = Final Drive Ratio
When using higher gear ratios, it is extremely important to
monitor the temperatures of the battery and motor. If the
battery is extremely hot, and/or the motor is so hot that you
cannot touch it, most likely you are over-geared and drawing a
lot of current.
The gear combination that comes on the Desert Truck (16-tooth
pinion / 88-tooth Spur) provides high-speed running intended
for hard surfaces, and this gearing is not recommended for
off-road, running in grass or constant starting and stopping.
Storage
When you are through running the model for the day
• Blow it off with compressed air or use a soft bristled paint
brush to dust-off the vehicle.
• Always disconnect and remove the battery from the
model whenever the model is stored. If the model will
be stored for a long time, then also remove the batteries
from the transmitter.