SUMMER 2005

1
NASA ROBOTICS ENGINEERING PROGRAMMABLE LOGIC
CONTROLLERS

• SUMMER 2005
• BUILDING A SMALL
• VEX ROBOT
• LECTURE 9

2
PROGRAMMABLE LOGIC CONTROLLERS SINGLE CHIP
COMPUTER

• SINGLE CHIP COMPUTER (SCC) REFERS TO ONE SINGLE
  IC CHIP THAT HAS ALL THE COMPONENTS OF A COMPUTER

3
PROGRAMMABLE LOGIC CONTROLLERS SINGLE CHIP
COMPUTER

• USUALLY A SCC CHIP CONTAINS CPU, MEMORY AND I/O

4
PROGRAMMABLE LOGIC CONTROLLERS SINGLE BOARD
COMPUTER

• SINGLE BOARD COMPUTER (SBC) REFERS TO A COMPUTER
  MADE UP BY DISCRETE COMPONENTS ON A SINGLE BOARD

5
PROGRAMMABLE LOGIC CONTROLLERS SINGLE BOARD
COMPUTER

• IT USUALLY CONTAINS ON BOARD CPU, MEMORY AND I/O

6
PROGRAMMABLE LOGIC CONTROLLERS SINGLE BOARD
COMPUTER

• MODERN PERSONAL COMPUTERS ARE USUALLY SINGLE
  BOARD COMPUTERS

7
PROGRAMMABLE LOGIC CONTROLLERS RISC VERSUS CISC

• RISC (REDUCED INSTRUCTION SET COMPUTER) IS A
  NEWER INVENTION THAN THE TRADITIONAL CISC
  (COMPLEX INSTRUCTION SET COMPUTER)

8
PROGRAMMABLE LOGIC CONTROLLERS RISC VERSUS CISC

• RISC CONTAINS ONLY A FEW BASIC INSTRUCTIONS, ALL
  COMPLEX INSTRUCTIONS ARE DERIVED FROM THESE
  SIMPLE INSTRUCTIONS

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PROGRAMMABLE LOGIC CONTROLLERS RISC VERSUS CISC

• RISC IS MORE EFFICIENT BECAUSE IT REQUIRES LESS
  CYCLE FOR EACH INSTRUCTION

10
PROGRAMMABLE LOGIC CONTROLLERS RISC VERSUS CISC

• RISC IS MOSTLY USED CURRENTLY IN PORTABLE AND
  EMBEDDED APPLICATIONS

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PROGRAMMABLE LOGIC CONTROLLERS RISC VERSUS CISC

• CISC CONTAINS MANY COMPLEX INSTRUCTIONS

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PROGRAMMABLE LOGIC CONTROLLERS RISC VERSUS CISC

• EXAMPLE INSERT AN ELEMENT INTO A DOUBLE-LINKED
  LIST

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PROGRAMMABLE LOGIC CONTROLLERS RISC VERSUS CISC

• CISC REQUIRES MORE ADVANCED FEATURES SUCH AS
  PIPELINING IN ORDER TO HANDLE THESE INSTRUCTIONS

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PROGRAMMABLE LOGIC CONTROLLERS MACHINE LANGUAGE

• IT IS GENERALLY WRITTEN IN BINARY

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PROGRAMMABLE LOGIC CONTROLLERS MACHINE LANGUAGE

• THIS BINARY IS ALSO AN EXPRESSION OF THE INPUTS
  TO THE ARITHMETIC LOGIC UNIT

16
PROGRAMMABLE LOGIC CONTROLLERS MACHINE LANGUAGE

• MACHINE LANGUAGE IS VERY CPU SPECIFIC
• EACH CPU HAS ITS OWN INSTRUCTIONS

17
PROGRAMMABLE LOGIC CONTROLLERS WHAT DO ALL THE
INSTRUCTIONS GO?

• MANY PEOPLE SAY COMPUTER CAN UNDERSTAND MACHINE
  CODE

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PROGRAMMABLE LOGIC CONTROLLERS WHERE DO ALL THE
INSTRUCTIONS GO?

• A COMPUTER PHYSICALLY EXECUTES THESE COMMANDS AS
  A PROGRAMMABLE LOGIC CONTROLLER

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PROGRAMMABLE LOGIC CONTROLLERS WHAT DO ALL THE
INSTRUCTIONS GO?

• HERE IS A SIMPLE FLOW CHART

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PROGRAMMABLE LOGIC CONTROLLERS MEMORY

• MEMORY IS WHERE ALL THE INSTRUCTIONS GO

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PROGRAMMABLE LOGIC CONTROLLERS MEMORY

• DATA BUS FROM THE MEMORY GOES INTO CPU DATA BUS
  FOR INSTRUCTION / DATA TRANSFER

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PROGRAMMABLE LOGIC CONTROLLERS MEMORY
 

• ADDRESS BUS IS CONNECTED TO AN ADDRESS DECODER
  (USUALLY A COUNTER) THAT INCREASES EVERY CLOCK
  CYCLE

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PROGRAMMABLE LOGIC CONTROLLERS MEMORY

• CLOCK IS GENERATED BY A FREE RUNNING OSCILLATOR
  WHICH ALSO DETERMINES HOW FAST CAN INSTRUCTIONS
  FLOW INTO THE CPU

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PROGRAMMABLE LOGIC CONTROLLERS MEMORY

• CONTROL BUS IS TO CONTROL SIGNALS GENERATED BY
  THE CPU

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PROGRAMMABLE LOGIC CONTROLLERS ASSEMBLY

• ASSEMBLY LANGUAGE INTRODUCES THE WORD MNEMONICS

LDA LOAD INTO REGISTER A
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PROGRAMMABLE LOGIC CONTROLLERS ASSEMBLY

• A WORD IS USED TO REPRESENT BINARY OPERATORS
• EX MOV INSTEAD OF 0x07

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PROGRAMMABLE LOGIC CONTROLLERS ASSEMBLY

• ASSEMBLY LANGUAGE IS CPU SPECIFIC DUE TO ITS
  DIRECT TRANSLATION

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PROGRAMMABLE LOGIC CONTROLLERS HIGHER LEVEL
LANGUAGES COMPILATION

• AS PROGRAMS GET MORE COMPLICATED, COMPILERS WERE
  DEVELOPED

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PROGRAMMABLE LOGIC CONTROLLERS HIGHER LEVEL
LANGUAGES COMPILATION

• COMPILIERS RESULT IN HIGH LEVEL LANGUAGES
• C IS A TYPICAL LANGUAGE THAT REQUIRES
  COMPILATION

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PROGRAMMABLE LOGIC CONTROLLERS HIGHER LEVEL
LANGUAGES COMPILATION

• C IS MORE CPU INDEPENDENT THAN ASSEMBLY BECAUSE
  DIFFERENT COMPILERS GENERATED MACHINE LANGAUGES
  FOR EACH CPU

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PROGRAMMABLE LOGIC CONTROLLERS CLOSER LOOK AT A
COMPILER

• LEXICAL ANALAYSIS FIRST STAGE
• THE PURPOSE OF LEXICAL ANALYZERS IS TO TAKE A
  STREAM OF INPUT CHARACTERS AND DECODE THEM INTO
  A HIGHER LEVEL

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PROGRAMMABLE LOGIC CONTROLLERS CLOSER LOOK AT A
COMPILER

• SYNTACTIC ANALAYSIS SECOND STAGE
• TAKES THE PROGRAM SOURCE CODE AND ENSURES THE
  PROGRAM'S SYNTACTICAL CORRECTNESS AND BY BUILDING
  AN INTERNAL REPRESENTATION OF THE PROGRAM

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PROGRAMMABLE LOGIC CONTROLLERS CLOSER LOOK AT A
COMPILER

• CODE GENERATION THIRD STAGE
• THE OBJECTIVE CODE IS GENERATED (MACHINE CODE
  WITHOUT EXTERNALS AND STATIC LIBRARIES LINKED)

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PROGRAMMABLE LOGIC CONTROLLERS EXAMPLE CPU
PIC16F84

• PIC16F84 IS A LOW-END 8-BIT MICROCONTROLLER (SCC)
  MANUFACTURED BY MICROCHIP

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PROGRAMMABLE LOGIC CONTROLLERS EXAMPLE CPU
PIC16F84

• MAXIMUM FOR THIS MICROCONTROLLER IS 10 MHZ BUT WE
  USUALLY CLOCK IT AT 4 MHZ

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PROGRAMMABLE LOGIC CONTROLLERS EXAMPLE CPU
PIC16F84

• THIS MICROCONTROLLER HAS A BUILT-IN CRYSTAL
  DRIVER, DATA RAM, FLASH PROGRAM MEMORY, TTL
  BUFFERED I/O AND MANY SPECIAL FUNCTION REGISTERS

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PROGRAMMABLE LOGIC CONTROLLERS EXAMPLE CPU
ARCHITECTURE OVERVIEW

• INPUT CLOCK IS DIVIDED INTO Q1, Q2, Q3 AND Q4. IN
  Q1 CYCLE, INSTRUCTION IS FETCHED FROM THE PROGRAM
  MEMORY THROUGH INSTRUCTION REGISTER

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PROGRAMMABLE LOGIC CONTROLLERS EXAMPLE CPU
ARCHITECTURE OVERVIEW

• INPUT CLOCK IS DIVIDED INTO Q1, Q2, Q3 AND Q4. IN
  Q2 CYCLE, INSTRUCTION IS SEPARATED INTO OP-CODE
  AND OP-RAND. OP-CODE GOES INTO THE INSTRUCTION
  DECODER. OP-RAND GOES TO ALU

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PROGRAMMABLE LOGIC CONTROLLERS EXAMPLE CPU
ARCHITECTURE OVERVIEW

• INPUT CLOCK IS DIVIDED INTO Q1, Q2, Q3 AND Q4. IN
  Q3 CYCLE, OP-RAND AND DATA FROM DATA RAM OR W
  REGISTER (WORKING REGISTER) ARE PUT INTO ALU.

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PROGRAMMABLE LOGIC CONTROLLERS EXAMPLE CPU
ARCHITECTURE OVERVIEW

• INPUT CLOCK IS DIVIDED INTO Q1, Q2, Q3 AND Q4. IN
  Q4 CYCLE, RESULT IS PUT INTO THE W REGISTER.

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PROGRAMMABLE LOGIC CONTROLLERS EXAMPLE CPU
HARDWARE CONNECTIONS

• PIC16F84 HAS 18 PINS. FROM TOP LEFT THEY ARE RA2,
  RA3, RA4, MCLR, VSS, RB0, RB1, RB2, RB3, RB4,
  RB5, RB6, RB7, VDD, OSC2, OSC1, RA0, RA1

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PROGRAMMABLE LOGIC CONTROLLERS EXAMPLE CPU
HARDWARE CONNECTIONS

• RA0 RA4 AND RB0 RB7 ARE GENERAL I/O PORTS.
  RB0 CAN ALSO BE USED AS EXTERNAL INTERRUPT INPUT

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PROGRAMMABLE LOGIC CONTROLLERS EXAMPLE CPU
HARDWARE CONNECTIONS

• MCLR IS AN ACTIVE LOW RESET INPUT. IT IS SET
  LOGIC HIGH DURING NORMAL OPERATION, AND PULLED
  LOW TO RESET THE CPU

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PROGRAMMABLE LOGIC CONTROLLERS EXAMPLE CPU
HARDWARE CONNECTIONS

• VSS IS GROUND CONNECTION AND VDD IS SUPPLY
  VOLTAGE CONNECTION

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PROGRAMMABLE LOGIC CONTROLLERS EXAMPLE CPU
HARDWARE CONNECTIONS

• OSC1 CONNECTS TO ONE PIN OF THE CRYSTAL AND OSC2
  CONNECTS TO ANOTHER PIN OF THE CRYSTAL

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Dr. Jennifer Rochlis
51
Overview

• Build a technology and power rich crewed
  utility vehicle testbed
• Modular, multi-purpose, long-term use and
  development
• Incorporate new technologies as developed by each
  organization
• Lessons-learned incorporated without redesign of
  all subsystems
• Develop and demonstrate operations and mission
  concepts
• Leverage existing-but-separate EA activities into
  a common program
• Provide young engineers with hands-on experience
  in systems and operations

52
Overview

• Fully functional vehicle that can
• Transport 2 crew members (1 suited and 1
  shirt-sleeved or 2 suited)
• Traverse 10 degree slopes (30 degree Mars
  equivalent) and 1 ft tall rocks
• Provide up to a 6 mile drive capability
• Support multiple operating modes that include
  onboard, tele-operation, and autonomous

53
Overview

• Technology testbed to develop and demonstrate
• Autonomous System functions
• Stereo tracking, object following, and the
  ability to control the vehicle with hand signals
• Obstacle avoidance
• Automated sequencing of frequent/repetitious
  actions
• Fault Detection, Isolation, and Reconfiguration
• Voice Recognition and synthesis with an extensive
  vocabulary
• Teleoperation visual enhancements (augmented
  reality)
• On-rover suit recharge
• Use of MEMS devices (gyros and wireless
  communication devices)
• Rover navigation algorithms and hi-fidelity rover
  simulations
• Different cockpit designs for suited crew-members
• Operations concepts

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Subsystems
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Structure (ES)
Wireless Router Access Point
EVA Lights (2)
Hazard Avoidance Laser
Video Camera
GPS Antenna (2)
Battery System
EPDC Module
Drive Motor (4)
Touchscreen Display

• Future Plans
• Mount Mars drill

Steering System (2)
Liquid Air Recharge Dewar for Suit (2)
Embedded GPS/INS (EGI)
56
Drive/Suspension/Steering/Electronics Subsystem
(ER)

• System Description
• Four wheel drive with motors, gearboxes and
  fail-safe brakes in each wheel
• Ability to steer the front wheels, rear wheels,
  or both sets of wheels
• Four wheel independent adjustable suspension
• Software and electronics that provide control of
  the drive motors for vehicle motion, steering
  motors and braking system

57
Crew Accommodations (EC)

• Hand controller interface
• Arm rest on center console
• Seat restraints
• Seat and foot rest
• Ingress aids (hand holds/grab bar/step bar)
• Mark III and I-Suit with suit recharge (increases
  suit pressurized time using on-board liquid air
  resupply dewars)
• Voice communication system
• Science trailer
• Portable drill rig

• Future Plans
• Add ergonomic adjustability
• Seat height
• Hand controller fore/aft height
• Foot rest width and fore/aft location
• Design and fabricate additional grab bar
• Design and fabricate seat restraints that can be
  manipulated by the suited subject
• Integrate suit recharge for 2 suited crewmembers
  (dewars, fill lines, possible seat modification,
  etc.)

58
Navigation System (EG)
10 km operational range
Range and range-rate data provided by comm system
relative to lander.
Lander planetary location surveyed by DSN. (Use
GPS solution as known location for field test.)
IMUs onboard rover propagate path between comm
measurement updates
Initial rover deploy location wrt lander well
known
Navigated path stored on lander and rover for
retracing
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Navigation System (EG)
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Display and Control System (ER)

• Enables on-board and teleoperated driving and
  monitoring
• Provides vehicle and environmental status
  information (e.g. situation awareness displays,
  caution and warning) and allows operator to
  execute driving commands and subsystem commands
• LabView software running on rugged touchscreen,
  on base-camp, and hand-held computers
• Designed to be operated by suited crewmember
• Future Plans
• Re-design of location of DCS for suited crew
  access
• Add sunlight readable monitor to the onboard
  system
• Work with EV to increase capability of wireless
  video system for teleop driving
• Incorporating lessons learned and user inputs
  from site tests

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Raw Image
360deg
180deg
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Autonomy and Onboard Software (ER)

• SCOUTs onboard autonomy software includes
• Point to point navigation (tracking to a fixed
  point)
• Human following (continuous tracking to a moving
  point)
• Obstacle avoidance
• Pose gathering, recording, monitoring (waypoints,
  astronaut, vehicle ground track)
• Data management, recording
• Future Plans
• Lower level drive control improvements for more
  varied terrain
• Obstacle avoidance improvements

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Stereo Tracking Following of Humans (ER)

• An active stereo vision system that enables SCOUT
  to track a person (by pointing cameras at them),
  follow the target around (by driving towards
  them) receive commands based on gestures

• Future Plans
• Use combination of gestures, recognized by stereo
  vision, speech so a person off-board can
  command SCOUT
• Improve matching of stereo measurements to 3D
  model of human
• Track the closest human as a safety measure
• Track arms for gesture recognition (initial
  version tested)
• Upgrade to higher resolution cameras to increase
  range over which smaller objects (arms) can be
  tracked (in work)
• Improve stereo camera pan/tilt control to follow
  human motion more reliably
• Integrate with vehicle control test in the
  field at Meteor Crater this fall

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Data Communications (EV)

• Vehicle on-board LAN using COTS network equipment
• Interconnects all vehicle computers to Ethernet
  backbone
• 5.8GHz Wireless Video Link to base station(4 mi.
  range/ 10 Channels)
• Can set up portable relay points to allow
  operations in locations that are not
  line-of-sight from the base station
• Wireless encryption

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EVA/Driving Lights Science Camera (EV)

• White LED technology for EVA lighting and driving
  lights
• Camera for continuous video streaming with
  Pan/tilt units
• Camera enclosure with cooling fan

EVA Lights and Camera systems mounted on SCOUT
rover light bar.

• 3.50 square LED light module

• Future Plans
• Reduce the size/weight of the EVA lighting system
• Purchase or design a more rugged Pan/Tilt Unit
  given the system weight

LED driving light assembly

• 2 LED light module

SCOUT I rover with EVA/Driving lights, science
camera.
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Operations

• Planned operations testing with the following
  partners
• Advanced Cockpit Evaluation System (ACES)
• Mars Drill
• CB crew office (Seismic Sensors)
• End of Year Field Test - Meteor Crater

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Steer-Bot
Wiz Kid

• A Robot With A Steering Linkage

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Special Features
Wiz Kid

• Fast
• Has an actual steering linkage
• Has 2 steering wheels in front

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Parts List
Wiz Kid

• (1) Battery
• (1) Battery Strap
• (1) Controller
• (1) RF Receiver
• (1) Yellow Telephone Cable
• (2) All-Purpose Tires
• (2) 1.895 Hub with Removable Tire
• (3) 2 Square Bars
• (4) 3 Square Bars
• (8) .318 Plastic Spacers
• (9) .182 Plastic Spacers
• (17) Collars with Threaded Screws
• (2) All-Purpose Tires
• (3) 36 Tooth Gears
• (3) 60 Tooth Gears
• (24) Keps Nuts
• (14) 8-32 x ¼ Screws
• (13) 8-32 x 3/8 Screws
• (9) 8-32 x ½ Screws

• (1) Long Bar
• (1) Chassis Bumper
• (4) Chassis Rails
• (2) 1 Fully Threaded Beams
• (4) 2 Partially Threaded Beams
• (4) 3 Partially Threaded Beams
• (1) Motor Module
• (1) Servo Module
• (7) Bearing Flats
• (2) Bearing Blocks
• (2) Lock Plates
• (2) Plus Gussets
• (1) Large Plate
• (2) 6-32 x ¼ Screw
• (2) 6-32 x ½ Screw
• (2) Gussets
• (1) Receiver Antenna Sleeve
• (1) Receiver Antenna Sleeve Holder
• (2) ½ Fully Threaded Beams

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Step 1-The Back Axel
Wiz Kid

• Parts Needed
• (2) 3 Square Bars
• (6) .318 Plastic Spacers
• (1) .182 Plastic Spacer
• (3) Collars with Worm Screws
• (2) All-Purpose Tires
• (1) 36 Tooth Gear

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Step 1
Wiz Kid

• 2 Different halves joined with 36 Tooth Gear
• First Axel
• Collar, All-Purpose Tire, (3) .318 Plastic
  Spacers, Collar
• Second Axel
• Collar, All-Purpose Tire, (2) .318 Plastic
  Spacers, 36 Tooth Gear, (1) .318 Plastic
  Spacers, (1) .182 Plastic Spacers

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Step 2-Finishing the Back Axel
Wiz Kid

• Parts Needed
• The two axel assemblies from Step 1
• (1) 36 Tooth Gear

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Step 3-The Rear Axel Support
Wiz Kid

• Parts Needed
• (4) Keps Nuts
• (2) Chassis Rails
• (4) Bearing Flats
• (4) 8-32 x ½ Screws

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Step 3
Wiz Kid
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Step 4-Attaching the Rear Axel Support
Wiz Kid

• Parts Needed
• The two support assemblies from Step 3
• (4) Keps Nuts
• (4) 8-32 x 1/2 Screws
• (1) Large Plate

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Step 4
Wiz Kid
77
Step 5.1-Drive-Motor Assembly
Wiz Kid

• Parts Needed
• (2)6-32 x ½ Screws
• (1) Bearing Flat
• (1) Motor Module
• (1) Gusset

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Step 5.1
Wiz Kid
79
Step 5.2-Drive-Motor Assembly Part 2
Wiz Kid

• Parts Needed
• (2) 1 Fully Threaded Beams
• (2) 8-32 x ¼

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Step 5.2
Wiz Kid
81
Step 5.3-Final Drive Motor Assembly
Wiz Kid

• Parts Needed
• (1) 60 Tooth Gear
• (1) 2 Square Bar

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Step 5.3
Wiz Kid
83
Step 6-Attaching the Drive Motor
Wiz Kid

• Parts Needed
• Completed Drive Motor Assembly from Steps 5.1
  thru 5.3
• (2) .182 Plastic Spacers
• (2) 8-32 x ¾ Screws

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Step 6
Wiz Kid
85
Step 7-Attaching the Control Module
Wiz Kid

• Parts Needed
• (3) Keps Nuts
• (2) 8-32 x ¾ Screws
• (1) 8-32 x ½ Screws
• (1) Control Module

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Step 7
Wiz Kid
87
Step 8-Attaching Support
Wiz Kid

• Parts Needed
• (4) 3 Partially Threaded Beams
• (4) 8-32 ¼ Screws

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Step 8
Wiz Kid
Put the completed piece aside for use in Step 16
89
Step 9-Steering Frame
Wiz Kid

• Parts Needed
• (4) 8-32 ¾ Screws
• (4) Keps Nuts
• (4) Bearing Flats
• (2) Chassis Rails

90
Step 9
Wiz Kid
91
Step 10.1-Wheel Modules
Wiz Kid

• Parts Needed
• (2) Collars
• (1) Skate Wheel
• (1) Bearing Block
• (1) 2 Square Bar
• (1) .182 Plastic Spacer

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Step 10.1
Wiz Kid
93
Step 10.2-Wheel Module Support
Wiz Kid

• Parts Needed
• Completed part from Step 10.1
• (2) 8-32 x 3/8 Screws
• (2) 2 Partially Threaded Beams

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Step 10.2
Wiz Kid
95
Step 10.3-Adding the Mounting Bracket
Wiz Kid

• Parts Needed
• Completed part from Step 10.2
• (2) 8-32 x ½ Screws
• (1) Bearing Flat
• (1) Plus Gusset

96
Step 10.3
Wiz Kid
97
Step 10.4-Adding a Gear
Wiz Kid

• Parts Needed
• Completed part from Step 10.3
• (2) Keps Nuts
• (2) .182 Plastic Spacers
• (2) 8-32 x ½ Screws

98
Step 10.4
Wiz Kid
99
Step 10.5-Finishing the Module
Wiz Kid

• Parts Needed
• Completed part from Step 10.4
• (3) Collars with Threaded Screws
• (1) Lock Plate
• (1) 3 Square Bar
• (1) .182 Plastic Spacer

100
Step 10.5
Wiz Kid

• You need two wheel modules, so repeat steps
  10.1-10.5 one more time. Keep the extra parts for
  the next step.

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Step 11-Starting the Steering Assembly
Wiz Kid

• Parts Needed
• (1) Completed Steering Module

102
Step 11
Wiz Kid

• Repeat this step with the other Steering Module

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Step 12-Connecting the Steering Assembly
Wiz Kid

• Parts Needed
• The two completed parts from Step 11
• (2) ½ Fully Threaded Beams
• (2) 8-32 x ¼ Screws
• (2) 8-32 x 3/8 Screws

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Step 12
Wiz Kid
105
Step 13-Attaching the Linkage
Wiz Kid

• Parts Needed
• The completed part from Step 12
• (1) Long Bar
• (2) 8-32 ¾ Screws
• (2) Lock Nuts
• (2) .182 Plastic Spacers

106
Step 13
Wiz Kid
107
Step 14-The RF Receiver and Support
Wiz Kid

• Parts Needed
• Completed Piece from Step 13
• (1) RF Receiver Module
• (1) Yellow Telephone Cable
• (1) Chassis Bumper
• (2) Keps Nuts
• (2) 8-32 x 3/8 Screws

108
Step 14
Wiz Kid
109
Step 15-The Antenna Holder
Wiz Kid

• Parts Needed
• Completed Piece from Step 14
• (1) 8-23 x 3/8 Screw
• (1) Keps Nut
• (1) Receiver Antenna Sleeve Holder
• (1) Receiver Antenna Sleeve

110
Step 15
Wiz Kid
111
Step 16-Attaching the Two Pieces
Wiz Kid

• Parts Needed
• Completed Piece from Step 15
• Completed Piece from Step 9
• (4) 8-32 3/8 Screws

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Step 16
Wiz Kid
113
Step 17.1-Steering Assembly
Wiz Kid

• Parts Needed
• (1) Servo Module
• (1) Gusset
• (2) 6-32 ¼ Screws

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Step 17.1
Wiz Kid
115
17.2-Adding to the Steering Assembly
Wiz Kid

• Parts Needed
• (2) .318 Plastic Spacers
• (1) 32 Tooth Gear
• (2) Collars
• (1) 2 Square Beam

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Step 17.2
Wiz Kid
117
Step 18-Attaching the Steering Servo
Wiz Kid

• Parts Needed
• (2) 8-32 ¼ Screws
• (2) Keps Nuts

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Step 18
Wiz Kid
119
Step 19-The Battery
Wiz Kid

• Parts Needed
• (1) Battery
• (1) Battery Strap

• Mount the Battery Strap on the front of the
  Steering Frame in the center.

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Congratulations, You finished Steer-Bot
Wiz Kid