Chassis Tuning; Slipper Adjustments; Troubleshooting Guide; Steering Rate - Losi RTR Manuel D'utilisation

EN

Chassis Tuning

The following are simple adjustments and easily maintained settings to assure proper operation and
performance. It is advised when making any adjustment that you do so in small increments and always
check for other parts of the chassis that are affected.

Slipper Adjustments

The Mini-Rock crawler is equipped with a slipper device offering both traction control and protection
for the transmission. The slipper is primarily used to help absorb sudden impacts on the drivetrain or
when using more powerful aftermarket motors and/or battery packs. Additionally, it can be used to
smooth out the flow of power to the wheels. Adjustment is made by turning the 3mm adjustment nut
clockwise (to the right) to reduce the slip, or counterclockwise (to the left) to increase the slip. As you
punch the throttle, the slipper should slip no more than an inch as it accelerates. With the included
motor and battery pack it should slip just a little. Make sure you replace the gear cover before running.

Troubleshooting guide

Problem Possible Cause
Vehicle doesn't operate Battery not charged or plugged in
Receiver switch not "On"
Transmitter not "On" or low batteries
Motor runs but rear wheels Pinion not meshing with spur gear
don't move
Pinion spinning on motor shaft
Slipper too loose
Transmission gears stripped
Steering doesn't work Servo plug not in receiver
Servo gears or motor damaged
Won't turn in one direction Servo gears damaged
Motor doesn't run Motor plugs loose
Motor wire broken
ESc damaged
ESc gets hot Motor over-geared
Driveline bound up
Poor run time and/or sluggish NiMH pack not fully charged
acceleration
charger not allowing full charge
Slipper slipping too much
Motor worn out
Driveline bound up
Poor range and/or glitching Transmitter batteries low
Transmitter antenna loose
Vehicle battery low
Loose plugs or wires
Slipper won't adjust Drive pin missing in shaft
Spur gear face worn out
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INCREASE SlIP dECREASE SlIP
Solution
charge battery/plug in
Turn on receiver switch
Turn on/replace batteries
Adjust pinion/spur mesh
Replace pinion gear on motor
check & adjust slipper
Replace transmission gears
check and replace drive pin
check if plug in/in all the way
Replace or repair servo
Replace servo
Plug in completely
Repair or replace as needed
contact Horizon Hobby Product Support
Use smaller pinion on motor
check wheels, suspension, and transmission
for binding
Recharge battery
Try another charger
check/adjust slipper
Replace motor
check wheels, transmission for binding
check and replace
check and tighten
Recharge or replace
check motor and power plugs
Replace drive pin
Replace spur gear and adjust slipper
LOSI MINI-ROCK CRAWLER • INSTRUCTION MANUAL

Steering Rate

Your transmitter is equipped with a steering rate control to the left of the steering wheel. This advanced feature, usually found only on competition-type
radios, allows you to adjust the amount the front tires move when you turn the steering wheel.
Less Rate

Steering Servo Saver Removal

The Mini-Rock crawler steering servo comes with a servo saver installed. As your rock crawling skills improve, we have included a steering arm that
eliminates the servo saver. Although this setup provides more precise steering, it does put your servo gears at risk for breakage. Use caution when the
steering servo is under severe loads.
1. center servo saver arm 2. Remove servo saver arm assembly from
the servo. Remove the steering ball stud
and install into solid servo arm.

Changing the Pinion gear/gear Ratio

Before you change the pinion gear, ask yourself why you are doing it. In general, if you change to a larger pinion, the wheel speed will increase but you will
see less acceleration and run time. This would only be advisable for low traction climbs. changing to a smaller pinion will give you quicker acceleration and
possibly a bit longer run time but a little less wheel speed. This would be good for high traction rock climbs. The pinion on the Mini-Rock crawler offers the
best balance of both. To change the pinion, remove the gear cover, loosen the motor screws and slide the motor back. Use the included 1.5mm allen wrench
to loosen the pinion setscrew. Place the new pinion on the end of the motor shaft and, using the flat of the pliers or a similar flat tool, push it on to the same
position as the one removed. See Setting the Gear Mesh below. Your Mini-Rock crawler comes equipped with a 14-tooth pinion, which provides an overall
ratio of 86:1. If you increase the pinion size to a 15-tooth gear, the ratio will change to 80:1 To decrease the pinion size to a 13-tooth will be 92:1.
NOTICE: When running aftermarket motors, check with the motor manufacturer for correct gearing. Never over-gear the motor as it can cause overheating,
damaging it and the speed control.

Setting the gear mesh

The motor screws should be slightly loose. Slide the motor forward allowing the pinion gear to mesh with the spur gear. Snug
(not tight) the bottom motor screw and try rocking the spur back and forth. There is a slight bit of movement before the motor
is forced to turn over. If not, pull the top of the motor back slightly and recheck. If there is too much slop between the gears,
push the top of the motor forward. When set properly, the wheels can be spun forward freely with very little noise. Make sure
to tighten both motor screws and replace the gear cover before running.

Tuning Tips

Weight: Adding weight to the front wheels of the Mini-Rock crawler will help increase traction and lower the over center of
gravity. Using the LOSA99201 Self Stick weights, carefully cut each piece in half and place inside the wheel as pictured. It is
important that the wheel weights be evenly placed inside the wheel to ensure that it is balanced.

Shock oil and Springs

The Mini-Rock crawler shocks are filled with Losi 30wt shock fluid. By switching to thinner shock fluid, the Mini-
Rock crawler will have more traction, quicker weight transfer and softer dampening. Doing the opposite will cause
the Mini-Rock crawler to react more slowly to input and have slower weight transfer. Adjusting these settings will
help adapt the Mini-Rock crawler to your conditions. Please note, the Mini-Rock crawler comes from the factory
with a stiffer rear spring to help minimize "Torque Flex" often found in 4WD driver rock crawlers.

Cleaning

Performance can be hindered if dirt gets in any of the moving suspension parts. Use compressed air, a soft paintbrush, or toothbrush to remove dust or dirt.
Avoid using solvents or chemicals as they can actually wash dirt into the bearings or moving parts as well as cause damage to the electronics.
LOSI MINI-ROCK CRAWLER • INSTRUCTION MANUAL
EN
Full Rate
3. With servo output shaft still centered,
install solid servo arm with the shorter
screw supplied and attach steering linkage.
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