DHK Hobby Optimus Operator's manual

1/8 Scale 4WD Brushless Electric Buggy
User’s Instruction Manual
用户使用说明书

Introduction
Thank you for choosing DHK’s Optimus! This model is designed in thorough research and assembled
with utmost craftmanship. It is easy to drive and it uses quality parts and accessories to achieve best
performance. It will bring you a lot of joy and fun when you drive this model.
Before starting to run the model, you are kindly requested to take some time to review this instruction
manual for a better operation. This easy to follow instruction manual aims to provide a general guideline
for end-users. Kindly note that a good understanding of the model , its relevant parts together with
other accessories packed in this consumer box will enable you to have fun in driving. Meanwhile, users
are recommended to conduct regular maintenance for a smooth performance. Failure to do so might
shorten the lifespan of your model. You are cordially advised that DHK Hobby makes all necessary parts
and accessories to support you for any problem during and after your driving.
Before you operate this radio controlled model, you must understand the following:
1.Make sure that all screws and nuts are tightened securely.
2.Make sure that the batteries are fresh or fully charged so the vehiche won’t lose control.
3.Do not drive the model in the following places/areas to avoid injury of people and damage to the
public property. Drive your model in open areas.
> On public streets or parks. Cause injury or death of pedestrians, young children, animals and pets.
> On highways. Cause accidents or damage of the model.
> In water. Cause damage to electronic components and parts, or direct failure of the model.
4.Check all signals and electronic parts are working properly.
After running, battery, ESC, and motor can be very hot. Make sure not to touch with bare hands.
Warning:
This high performance model can run very fast. It is designed and produced for people of 14+ years of
age to operate. Players under that age should be guided by adult supervision. Entry level players should
seek guidance and supervision from experienced model players. Players are responsible for any/all
accidental occurrences (human or animal injury, damage to property and possessions, breakage of the
model itself) due to improper operation of this model.
1

Model specications
Articles required to operate the model
8 pcs AA batteries (Ni-Mh or Ni-Cd rechargable batteries, or non-rechargable alkaline batteries) for
2.4GHz transmitter. Please refer to the 2.4GHz transmitter Instruction Manual.
Lipo balance charger (#P109) (for 2S/3S Lipo battery) 1,000mAh output with AC input.
2 Channel 2.4GHz radio system
Optimus comes with a full function 2 channel 2.4GHz radio transmitter and receiver. Please refer to the
2.4GHz User’s Instructions Manual for detail.
Brushless electronic speed control (ESC)
Optimus comes with 60A brushless electronic speed controller. Please refer to the instructions manual
of the ESC for detail.
Brushless electric motor
Overall length : 19.4" (493.3mm)
Width : 12.1" (307.7mm)
Height : 6.76" (171.9mm)
Wheelbase : 12.98" (330.1mm)
Ground clearance : 1.36" (34.6mm)
Weight (net) : 2920g
Front track/rear track : 10.23" (260.0mm)/10.43" (265.0mm)
Front tyres/rear tyres : Ф118,45mm/Ф118,45mm
Front wheels/rear wheels : Ф81,42mm/Ф81,42mm
Gear ratio : 10.68:1
Motor KV(RPM) : 2260
Power : 7.4V
Empty load current : 3.2A
Resistance(Ω) : 17.5-19.2Ω
Length(including motor shaft) : 75mm
Diameter : 36mm
Weight : 291g
Shaft diameter : 5mm
2

9kgs Servo
Note:
When the motor temperature is over 120˚C(248˚F), please add a fan over the motor for better
ventilation. Please refer to the parts list for the optional part motor cooling fan (Part#: P101).
Lipo Batteries
This model comes with single 11.1V 3200mAh Lipo battery pack. Handling Lipo batteries should be very
careful. Please read the following points with regard to charging and discharging Lipo batteries.
Charging the Lipo battery
Important warnings:
Be sure to follow these important warnings regarding the charging of Lipo batteries.
> Never leave a Lipo battery unattended at any time while being charged.
> Never charge a Lipo battery while it's inside the model. A hot pack could ignite wood, foam, plastic,
etc.
> Never charge Lipo battery with Ni-Mh or Ni-Cd peak charger. Only use a charger designed specically
for Lipo batteries which can apply the constant current/constant voltage charge technique.
> Never charge Lipo battery at currents greater than the "1C" rating of the battery.
> Never allow Lipo cells to overheat at any time. Cells which exceed 60˚C (140˚F) during charge can
and usually will become damaged physically and possibly catch re. Always inspect a battery which has
previously overheated and do not re-use if you suspect it has been damaged in any way.
> Always discontinue charging a Lipo immediately if at any time you witness smoke or see the battery
starting to swell up. This may cause the battery to rupture and/or lead, and the reaction with air may
cause the chemicals to ignite, resulting in re. Disconnect the battery and leave it in a safe reproof
location for approximately 15 minutes.
> Always charge a Lipo battery in a fireproof location, which could be a container made of metal,
ceramic tile, or a bucket of sand.
> Never allow a battery's positive and negative leads to accidentally touch each other. This will result in
a short circuit and cause permanent damage to your battery and charger.
> Always monitor the battery and charger during the entire charge process. Never leave the battery and
charger unattended during charge!
> Never continue to charge the Lipo batteries if the charger fails to recognize full charge. Overheating or
swelling of the Lipo cells is an indication that a problem exists and the batteries should be disconnected
from the charger immediately and placed in a reproof location.
Discharging the Lipo battery
> Never leave a Lipo battery unattended at any time while being discharged.
> Always discharge Lipo batteries in a reproof location, which could be a container made of metal or
on ceramic tile.
> Always connect the battery's lead marked "Discharge" or "TO ESC" to the electronic speed controller.
Never attempt to connect the battery's "CHARGE" lead to the ESC.
Features : Metal gears, ball bearings
Working voltage : 6.0V
Speed (seconds/60˚C) : 0.16sec
Torque : 9kg/cm (88.3Ncm)
Net weight : 60g
Size(LxWxH) : 55x21x43mm
3

> It is strongly recommended to use an ESC which is designed to handle the low voltage cutoff points or
Lipo batteries (Always follow the instructions provided with the ESC for proper operation). Discharging
Lipo batteries below 2.5V per cell (Norm is 3.7V per cell, at 4.2V once fully charged) can cause
permanent damage and limit the number of times the battery can effectively be used again.
> Never discharge Lipo batteries at currents which exceed the discharge current rating of the battery
as this can often cause a cell to overheat. Do not allow a Lipo cell to exceed 60˚C (140˚F) during
discharge.
Caution!
Cells may be hot. Do not allow the battery's internal electrolyte to get in the eyes or on skin. Wash
affected areas with soap and water immediately if they come in contact with the electrolyte. If electrolyte
makes contact with the eyes, flush with large amounts of water for 15 minutes and seek medical
attention immediately.
Carefully inspect Lipo batteries which have been involved in a crash for even the smallest of cracks,
splits, punctures or damage to the wiring and connectors.
Disposal of Lipo batteries
Unlike Ni-Cd batteries, Lithium-polymer batteries are environmentally friendly. For safety reasons,
it's best that Lipo cells be fully discharged before disposal (however, if physically damaged it is
not recommended to discharge Lipo cells before disposal). The batteries must also be cool before
proceeding with disposal instructions. To dispose of Lipo cells and packs:
> If any Lipo cell in the pack has been physically damaged, resulting in a swollen cell or a split or tear in
a cell's foil covering, do not discharge the battery.
> Place the Lipo battery in a reproof container or bucket of sand.
> Connect the battery to a Lipo discharger. Set the discharge cutoff voltage to the lowest possible value.
Set the discharge current to a C/10 value, with "C" being the capacity rating of the pack.
> Discharge the battery until its voltage reaches 1.0V per cell or lower. For resistive load type
dischargers, discharge the battery for up to 24 hours.
> Submerse the battery into bucket or tub of salt water. This container should have a lid, but it does not
need to be air-tight. Perhaps a bucket or tub containing 3 to 5 gallons of cold water, and mix in 1/2 cup
of salt per gallon of water. Drop the battery into the salt water. All the battery to remain in the tub of salt
water for at least 2 weeks.
> Remove the Lipo battery from the salt water and place it in the normal trash.
Terminology
Electronic speed control (ESC)
An electronic circuit with the purpose to vary an electric motor’s speed, its direction and possibly also to
act as a dynamic brake. ESCs are often used on electrically-powered radio controlled models.
An ESC can be a stand-alone unit which plugs into the receiver's throttle control channel or incorporated
into the receiver itself, as is the case in most toy-grade R/C vehicles. Some R/C manufacturers that
install proprietary hobby-grade electronics in their entry-level vehicles, vessels or aircraft use onboard
electronics that combine the two on a single circuit board.
Brushless DC motors (BLDC motors, BL motors)
Also known as electronically commutated motors (ECMs, EC motors). BLDC motors are synchronous
electric motors powered by direct-current (DC) electricity and having electronic commutation systems,
rather than mechanical commutators and brushes. The current-to-torque and voltage-to-speed
relationships of BLDC motors are linear.
4

BLDC motors may be described as stepper motors, with xed permanent magnets and possibly more
poles on the rotor than the stator, or reluctance motors. The latter may be without permanent magnets,
just poles that are induced on the rotor then pulled into alignment by timed stator windings. However,
the term stepper motor tends to be used for motors that are designed specically to be operated in a
mode where they are frequently stopped with the rotor in a dened angular position.
RC servos
Servos are hobbyist remote control devices typically employed in radio-controlled models, where they
are used to provide actuation for various mechanical systems such as the steering of a car, the control
surfaces on a plane, or the rudder of a boat.
Due to their affordability, reliability, and simplicity of control by microprocessors, RC servos are often
used in small-scale robotics applications.
RC servos are composed of an electric motor mechanically linked to a potentiometer. A standard RC
receiver sends Pulse-width modulation (PWM) signals to the servo. The electronics inside the servo
translate the width of the pulse into a position. When the servo is commanded to rotate, the motor is
powered until the potentiometer reaches the value corresponding to the commanded position.
RC servos use a three-pin 0.1" spacing jack (female) which mates to standard 0.025" square pins (which
should be gold-plated, incidentally). The most common order is Signal, +voltage, ground. The standard
voltage is 6VDC, however 4.8V and 12V has also been seen for a few servos. The control signal is a
digital PWM signal with a 50Hz frame rate. Within each 20ms timeframe, an active-high digital pulse
controls the position. The pulse nominally ranges from 1.0ms to 2.0ms with 1.5ms always being center
of range. Pulse widths outside this range can be used for "overtravel" -moving the servo beyond its
normal range. This PWM signal is sometimes (incorrectly) called Pulse Position Modulation (PPM).
The servo is controlled by three wires: ground, power, and control. The servo will move based on the
pulses sent over the control wire, which set the angle of the actuator arm. The servo expects a pulse
every 20 ms in order to gain correct information about the angle. The width of the servo pulse dictates
the range of the servo's angular motion.
A servo pulse of 1.5 ms width will typically set the servo to its "neutral" position or 45°, a pulse of 1.25
ms could set it to 0° and a pulse of 1.75 ms to 90°. The physical limits and timings of the servo hardware
varies between brands and models, but a general servo's angular motion will travel somewhere in the
range of 90° - 120° and the neutral position is almost always at 1.5 ms. This is the "standard pulse
servo mode" used by all hobby analog servos.
A hobby digital servo is controlled by the same "standard pulse servo mode" pulses as an analog servo.
Some hobby digital servos can be set to another mode that allows a robot controller to read back the
actual position of the servo shaft. Some hobby digital servos can optionally be set to another mode and
"programmed", so it has the desired PID controller characteristics when it is later driven by a standard
RC receiver.
RC servos are usually powered by the receiver which in turn is powered by battery packs or an
Electronic speed controller (ESC) with an integrated or a separate Battery eliminator circuit (BEC).
Common battery packs are either NiCd, NiMH or Lithium-ion polymer battery (LiPo) type. Voltage
ratings vary, but most receivers are operated at 5V or 6V.
5

6
Parts List
Number Desc
8381-100 Assembly of diff gear box
8381-101 Diff set
8381-102 Diff outdrive/pins (dia 2*10mm)
8381-103 Pins(dia 2*10mm) (16 pcs)
8381-104 Flathead screw-coarse thread(KB2.6*10mm) (16
pcs)
8381-105 Crown gear-41T (large)/pinion gear-11T (small)
8381-106 Diff case set/diff case cover/diff gasket
8381-107 Washer-A/washer-B (8 pcs each)
8381-108 Gear-18T (2 pcs)/gear-12T (4 pcs)
8381-109 O Ring(dia 8mm * dia 2mm) (16 pcs)
8381-110 Ball bearing(dia 10mm * dia 15*4mm) (2 pcs)
8381-111 Diff pins(dia 4*25.8mm) (4 pcs)
8381-112 Assembly of the pinion gear
8381-113 Flathead screw(KM2.6X6mm) (16 pcs)
8381-114 Ball bearing(dia 8mm * dia14*4mm) (2 pcs)
8381-115 Pins(dia 2*8mm) (16 pcs)
8381-116 Pinion gear outdrive/pins(dia 2*8mm)
8381-117 Ball bearing(dia 5 mm * dia 11*4mm) (2 pcs)
8381-118 Diff gear box-F/R
8381-119 B head screw-coarse thread(BB3*16mm) (16 pcs)
8381-200 Central diff gear box(complete)
8381-201 Central diff set
8381-202 Center diff pins/pins(dia 2*10mm)
8381-203 Spur gear-43T(plastic) (2 pcs)
8381-204 Lock nut (M4*4mm) (16 pcs)
8381-205 Center diff outdrive/lock nut(M4*4mm)
8381-206 Center diff gear box/center diff gear box plate
8381-207 B head screw-coarse thread(BB3*20mm) (16 pcs)
8381-300 Shock absorber complete (2 pcs)
8381-301 Shock cap (2 pcs)
8381-302 Shock connecting rod-upper/lower/O ring (dia
12mm * dia 2mm)
8381-303 Shock adjust ring /O ring (dia 18.5mm * dia 1.5mm)
(2 pcs)
8381-304 Shock body (2 pcs)
8381-305 Shock ball (8 pcs)
8381-306 M3 nylon nut (8 pcs)
8381-307 Lower shock mount/piston/O ring(dia 13mm * dia
1.5mm)
8381-308 O ring (16 pcs)
8381-309 Shock shaft (4 pcs)
8381-310 Shock spring (4 pcs)
8381-400 Anti-roll bar assembly
8381-40L Assembly of anti-roll bar linkage-Left
8381-40R Assembly of anti-roll bar linkage-Right
8381-401 Anti-roll bar rod end (8 pcs)
8381-402 Anti-roll bar linkage (4 pcs)
8381-403 Anti-roll bar pivot ball-upper/lower (4 sets)
8381-404 Lock nut(M3*3mm) (8 pcs)
8381-405 Anti-roll bar(dia 2.2mm) (2 pcs)
8381-50L Assembly of upper sus.arm-Left
8381-50R Assembly of upper sus.arm-Right
8381-501 Upper sus.arm ball (4 pcs)
8381-502 Upper sus.arm/rod end (2 sets)
8381-503 Upper sus.arm linkage (2 pcs)
8383-600 Assembly of buffer set
8381-601 Brass washer (4 pcs)
Number Desc
8381-602 Buffer bushing/adiustment ring
8381-603 Buffer spring (4 pcs)
8381-604 Buffer sus.arm-upper/lower/steering sus.arm
8381-605 B head screw-coarse thread(BB3*12mm) (16 pcs)
8381-606 Screw bushing (16 pcs)
8381-601 Steering plate
8381-608 Shaft (2 pcs)
8381-6Z0 Assembly of steering linkage (2 pcs)
8381-6Z1 Steering linkage (2 pcs)
8381-6Z2 Plastic rod end (8 pcs)
8381-6Z3 Double way ball end (8 pcs)
8381-701 Upper sus.arm mount-rear/suspension mount
8381-702 B head screw-coarse thread(BB3*14mm) (16 pcs)
8381-703 B head screw-coarse thread(BB3*10mm) (16 pcs)
8381-704 Sus.arm long axle/short axle (2 sets)
8381-705 E-Clip(dia 2*0.4mm) (16 pcs)
8381-706 Lower sus.arm-front (2 pcs)
8381-707 Drive shaft set/revolving shaft (2 sets)
8381-708 Wheel axle (2 pcs)
8381-709 Steering arm (2 pcs)
8381-710 Ball bearing(dia 5mm * dia 10*4mm) (2 pcs)
8381-711 Hex adapter/nut-M12
8381-712 Pins(dia 2*16mm) (16 pcs)
8381-713 B head screw(BM3*12mm) (16 pcs)
8381-714 C-hub (2 pcs)
8381-715 B head screw(BM3*20mm) (16 pcs)
8381-716 Lock nut(M4*10mm) (16 pcs)
8381-717 Brace (2 pcs)
8381-718 Pivot ball mount (4 pcs)
8381-719 Upper sus.arm shaft (4 pcs)
8381-720 Front bumper/upper sus.arm mount-front
8381-721 Lower sus.arm plate-front
8381-726 B head screw-coares thread(BB3*18mm) (16 pcs)
8383-001 Tire complete (black rims) (2 pcs)
8381-801 Lower sus.arm-rear (2 pcs)
8381-802 Rear hub-L/F
8381-803 B head screw(BM3*18mm) (16 pcs)
8381-804 Wing mount/wing brace-L/R
8381-805 B head screw(BM3*10mm) (16 pcs)
8381-806 Rear wing rod-long/short
8381-807 Pin-A(dia 1.5mm) (16 pcs)
8383-002 Rear wing (black)
8381-9M1 Motor mount-Upper/Lower
8381-9M2 Motor gear-15T/Lock nut(M4*4)
8381-9S0 Assembly of 9kgs servo (with servo horns)
8381-9S1 Servo mount
8381-9S2 Servo steering plate (2 pcs)
8381-9S3 B head screw(BM3*6mm) (16 pcs)
8381-9Z0 Assembly of steering tie rod
8381-9Z1 Steering tie rod (2 pcs)
8383-003 Chassis
8381-002 Side guard-L/R
8382-003 Battery mount-A/B
8381-004 Upper deck mount-F/R

Number Desc
8381-005 Central drive shaft-A
8381-006 Central drive shaft-B
8381-007 Receiver cover-upper/lower
8381-008 Antenna tube (3 pcs)
8381-009 Pin-B(dia 1.2mm) (16 pcs)
8381-010 Screw washer
8381-011 Flathead screw(KM3X10mm) (16 pcs)
8381-012 Flathead screw-coarse thread(KB3*10mm) (16
pcs)
8381-013 Flathead screw-coarse thread(KB3*12mm) (16
pcs)
8381-014 Flathead screw (KM3*5mm) (16 pcs)
8381-015 Flathead screw(KM3X18mm) (16 pcs)
8381-016 Upper deck-A
8381-017 Upper deck-B
8381-018 Body post-F/R/wire mount-A
8383-003 Battery cover
8381-020 Hex driver H17
8381-021 Painted body
H104 Brushless ESC (60A)
H105 Brushless motor (KV:2260)
H106 LiPo battery (11.1V, 20C, 3200mAh)
D302 2 channel 2.4GHz transmitter complete (with
receiver)
D302H 2 channel 2.4GHz LCD transmitter w/ receiver
(Optional)
D302R 4 channel 2.4GHz receiver
7

8381-200 Assembly of the
center diff gear box
8381-100 Assembly of the
diff gear box
8381-117
8381-204
8381-205
8381-204
8381-207
8381-206
8381-205
8381-206
8381-202
8381-110
8381-111
8381-108
8381-107
8381-108
8381-109
8381-110
8381-201
8381-109
8381-103
8381-106
8381-107
8381-108
8381-107
8381-108
8381-107
8381-106
8381-203
8381-104
8381-103
8381-202
8381-201
8381-101
8381-112
8381-118
8381-118
8381-119
8381-110
8381-110
8381-112
8381-115
8381-105 8381-116
8381-107
8381-114
8381-113
8381-107
8381-108
8381-102
8381-111
8381-103
8381-106
8381-108
8381-107
8381-108
8381-109
8381-107
8381-101
8381-108
8381-107
8381-106
8381-105
8381-103
8381-109
8381-102
8381-104
8381-50R
8381-50L
8381-501
8381-501
8381-502
8381-503
8381-502
8381-502
8381-503
8381-502
8381-50L Assembly of upper sus.arm-Left
8381-50L Assembly of upper sus.arm-Right
8381-606
8381-606
8383-300 Assembly of the
shocks
8383-600 Assembly of the
buffer set
8381-400 Assembly of the
sway bar
8381-601
8381-405
8381-404 8381-403
8381-403
8381-402 8381-402 8381-401
8381-403
8381-401 8381-402 8381-401
8381-40R
8381-40L
8381-309 8381-306
8381-501
8381-605 8381-606
8381-601 8381-608
8381-608
8381-601 8381-604
8383-601 8381-605
8381-601 8381-602 8381-604 8381-604 8381-603 8381-602
8381-310
8381-305
8381-305
8

8381-723
8381-725
8381-723
8381-724
8381-725
8381-723
8381-723
8381-724
8383-700 Assembly of the
front sus.arm system
8381-708
8381-110
8383-001
8381-119
8381-705
8381-400
8381-705
8381-119
8381-100
8383-001
8383-300
8383-300
8381-50L
8381-50R
8381-719
8381-719
8381-726
8381-721
8381-119
8381-715
8381-715
8381-720
8381-720
8381-703
8381-306 8381-718
8381-718
8381-717
8381-705
8381-726
8381-716
8381-716
8381-705
8381-714
8381-714
8381-710
8381-703
8381-702
8381-705
8381-119
8381-119
8381-711
8381-711
8381-712
8381-709 8381-110
8381-103
8381-705
8381-708
8381-707
8381-712
8381-711
8383-001
8381-711
8381-710
8381-709
8381-110
8381-707
8381-103
8381-707
8381-705
8381-705
8381-704
8381-704
8381-704
8381-704
8381-706
8381-706
8381-701
8381-701
9