FIRST Rookie Workshop Presented by

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FIRST Rookie Workshop Presented by

• FIRST Team 246
• Overclocked
• Boston University and
• Boston University Academy

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• Gary Garber, Instructor of Physics B.U.A.
• Brandon Mensing, Undergraduate B.U.
• Andrew Macrae, Senior at B.U.A.
• Toby Waite, Senior at B.U.A.

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Todays Workshop

• Planning your build season
• Mechanical Aspects of the Robot
• Electronics of the Robot
• Programming the Robot
• Logistics

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Team Organization

• Making Sense of the Madness

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Divisions

• Divide and conquer when possible
• How big is your team??
• Mechanical
• Electrical
• Programming
• PR, Fundraising, Spirit, Outreach, Etc.

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A Mentor Cannot Be Too Organized

• Keep an updated hard copy of the manual in the
  lab.
• Give someone the task of printing and attaching
  updates as they come out.
• Have a place for everything in your lab
• Tools in in a chest or on a shelf
• Designate an area/shelf for in-progress
  parts/projects
• Post, post, post, post!
• Important numbers next to the phone
• Safety procedures next to machine tools
• Closeup instructions for the shop
• Have the students spend just a little time each
  day cleaning
• Keep copies of important documents online for
  easy access anywhere
• Have a way to track those pesky long-term To-Dos

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Brainstorming

• Listen to the podcast for more depth
• Start brainstorming on Sunday
• Split into groups(?)
• Talk about strategy before design
• Try to pick a strategy that you can do
• Then have everyone throw out ideas
• Start writing out ideas for designs and
  mechanisms without drawing or discussing them
• Attempt to decide on a few constants
• Usually, the drive base will look about the same

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Getting It Built

• Always imagine that youre shipping tomorrow
• The point is to have a working robot
• Dont work on new mechanisms when you arent
  driving reliably
• Focus on building things (also the field)
• Dont just talk strategy or debate all day
• Build, test, break and revise
• Give individuals specific tasks
• Even if its a matter of just going to the
  manuals and reading
• Review the overall schedule of the build often
• Keep a counter posted in your shop with the days
  remaining

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Mechanical

• Designing and Building
• an FRC Robot, Quickly

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Just 6 Weeks

• That sound you hear is a student on the
  mechanical team trying to get out of the shipping
  crate you closed too early.
• -Al Skierkiewicz, Team 111

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The Kit Bot

• The Kit-Bot is included in your Kit of Parts
• Can be built in a few afternoons
• Chassis, motors, transmissions, wheels, sprockets
  and chain
• The assembly video is in your Manuals folder

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Building a Robot

• 4 Wheels vs. 2 Wheels

ROBOT
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Building a Robot

• 4 Wheels vs. 2 Wheels

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Building a Robot

• 4 Wheels vs. 2 Wheels

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How about 6 Wheels?

• 6 Wheels allow for stability, turning, and less
  slipping when maneuvering.
• Kit-Bot easily works as a 6-wheel drive base.
  The center hole for the 3/8 axels is slightly
  lower than the rest.
• It does however make for a bit more complication,
  expense and weight.

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Building a Robot

• Center of Gravity

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Building a Robot

• Wheel Suggestions

• It doesnt matter how many wheels you have, as
  long as they all are driven
• If you plan to turn, you should only have
  grippy tires
• Incline Conveyor Belt (wedge-top, rough-top)
• Pneumatic Tires
• Soft Rubber Tires
• Skids should be slick
• HDPE or Delryl
• Omni-wheel/Wonder-wheel

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Building a Robot

• Chain Wrap

Idler
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Building a Robot

• Further Gear and Sprocket Recommendations

• All sprockets must have gt120º of chain wrap
  (180º is better)
• Chains stretch as they wear, have a way to
  adjust tension
• Idler gears can be used to change direction of
  motion or adjust amount of chain wrap on a
  sprocket

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Building a Robot

• Wheelbase Recommendations

• Short and wide robots turn easily and have lots
  of control, but will tend to not drive straight
• Long and narrow robots will not turn easily and
  will have poor turning control, but will tend to
  drive very straight
• The task matters a lot in this decision

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Moving from VEX to FRC

• FRC
• Set screws inhale audibly. Use a slot and key,
  shear pin, or other secure system, or use an axle
  instead of a shaft.

• VEX
• Set screws are used to attach things to shafts

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Moving from VEX to FRC

• FRC
• Casters arent such a great idea. They can
  prevent the robot from going over obstacles, and
  reduce traction on driven wheels.
• All wheels on the ground should be driven

• VEX
• Casters and two-wheel drive systems work well

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Moving from VEX to FRC

• FRC
• If properly designed, broken parts are easy to
  fix. Make sure that electronics, shafts, motors,
  gears, chains, and any other likely to break
  parts are accessible.

• VEX
• Broken parts are usually easy to fix.

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Moving from VEX to FRC

• FRC
• An out of control FRC robot can be very dangerous
  to itself and bystanders. Always take proper
  precautions when building and testing.

• VEX
• Robots cant do much damage.

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Moving from VEX to FRC

• FRC
• In most cases, ball bearings should be used on
  all shafts. Each shaft should be supported in
  exactly two places.

• VEX
• Friction bearings are used on shafts

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Moving from VEX to FRC

• FRC
• Very few parts will fit together without
  modification. You will have to be creative when
  interfacing your motors, wheels, and other
  mechanical parts.

• VEX
• Everything is designed to fit together

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Moving from VEX to FRC

• Sample FRC Motors

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Kit-Bot

• Start building it when youre done with initial
  brainstorming.
• You can add and modify it a LOT.
• However, its best NOT to cut away sections of
  the chassis. The design is dependent on all the
  parts.

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Final Advice

• KISS Keep It Simple Silly
• Dont over-engineer
• Think outside the box
• Dont try to do all the objectives
• Do a few things well rather than a lot of things
  poorly
• Keep the weight limit in mind
• Adding weight is much easier than removing it

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Final Advice

• Break it early, break it often
• Version 2.0 is often better
• If you know something might/will break at
  competition, make a duplicate before you ship!
• Practice, Practice, Practice
• Get something driving as soon as possible, even
  before the mechanisms are attached
• Driver practice is just as important as
  mechanical design

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FIRST Robotics

• The Control System
• And
• Good Wiring Practices

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Innovation First
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Spike

• Simply a Relay or On/OFF Switch
• Also runs in reverse
• Controlled by a 5VDC Output from controller
  through software
• Components Wired to Spikes
• Air Valves, Compressor
• Low current Motors
• Rated and fused at 20 amps except compressor 20
  amp breaker

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Victor

• Like a Spike, but with variable outputs
• Controlled by a PWM (Pulse Width Modulation)
  signal from the RC
• Components Wired to Spikes
• High current Motors
• Motors that need proportional control
• Can be used with higher currents (up to 40 A)

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RC and OI
Innovation First
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RC Setup
Robot Controller Basic Setup
Backup Battery
Team Color
Victor 884s
12V Battery Power
Servos
Potentiometers, Gyro
Limit, Pressure, Optical Switches
DB9 Cable
Spikes (Relays)
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OI Setup
Operator Interface Basic Setup
AC Adaptor
DB9 Cable
Joystick 1
Joystick 3
Joystick 2
Joystick 4
Set Team Number
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Setting team number
Setting Team Number
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Wiring Diagram
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Wiring Guidelines

• Red and White wire is positive () DC
• Black wire is negative (-) DC (or ground)
• Use correct size crimp connectors
• Crimp well!
• Insulate your connections using electrical tape.
• Lay out wiring logically, trying to minimize wire
  length.
• Always check your work before you turn systems on
  for the first time.
• Protect your electronics from other robots!
• Labels and color-coding simplifies everything.

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Wiring Requirements
Wire size is minimum, larger is also acceptable
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Wiring Safety

• Color code your wiring!
• Insulate all of your connections.
• DO NOT work on the electronics while they are
  turned on.
• Secure all components and wires (especially the
  battery)
• The chassis is NOT an acceptable ground.
• Electricity and liquids do not mix.

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Custom Circuits

• May Not
• Directly Control Outputs
• Interfere with Operation of Other Robots
• Used for Wireless Communications
• Connect to programming, tether, competition ports

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Programming

• Programming the Robot for Beginners
• The Default code

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Checklist

• This is just a list of the things you will need
  before loading and testing code.
• They are all recommended
• Technically the disable and autonomous dongle and
  the serial port computer are optional, but
  probably not worth the time

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Default Code

• Designed to help you to have a fully functional
  robot within the six week period
• One will be provided next year
• Doesn't have an autonomous, you may or may not
  get to modifying it
• Most teams barely modify their drive code from
  what appears in it.
• Four drive codes have been provided in their hex
  files, use them if it is connected so that it
  responds differently to the joystick inputs.

ROBOT
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Additional things in the default code

• Short of autonomous code and orientations very
  little will be chaged from the default code by
  any teams so
• There are also systems which support pneumatics
  systems on the robot if you get to adding them

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Getting ready to load the code

• Install IFI loader on your serial PC. You should
  be able to get it off of this CD but a more
  recent version will be available on the web soon.
• Load code as indicated in the instructions

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Testing the default code

• The default code assumes certain orientations of
  motors and electrical connections. Four different
  versions are included that allow the drive
  signals to be reversed to any of the wheels.
• Joysticks should each control a wheel, and
  pushing it forward should make the wheel drive
  forward. If one of the wheels is not running the
  proper direction change the autonomous code for a
  different hex file

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Safety

• Even the kitbot chassis is a force to be reconed
  with.
• Avoid driving when people are near the robot, and
  don't even power on when people are close.
• The disable switch is very helpful if you want to
  run diagnostics on the robot while it is on.
• If you have to mount the robot on blocks so it
  wont run away
• The joysticks have trim tabs. Using them means
  that you will be able to make the robot stay
  still when hands are off the joysticks

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Deadlines

• Yearbook Entries TOMORROW
• January 6th Kickoff George Sherman Union and
  Sargent Gymnasium at Boston University
• Arrange Shipping/Transportation
• Robot Ship Deadline Tuesday Feb 20th

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Team 246 Support

• Thursday Dec 14th Advanced Topics
• Make-A-Crate Workshop
• Workshop Safety Training
• Open Workshop Weekend
• Press Conference

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Getting Help

• Call us! (617-358-3854)
• Listen to our daily podcast
• Check the QA on FIRSTs site
• Contact FIRST
• Checkout www.chiefdelphi.com
• Read the manuals