6 2 Wheel Drive The Good The Bad Cheap; Kitbot is 2WD Very simple to buildThe BadEasily spins outDifficulty with inclinesLoses traction when drive wheels leave floor
7 4 Wheel Drive The Good The Bad More easily controlled Pretty simple to buildBetter tractionThe BadTurning in place is more difficultCompromise between stability and maneuverability
8 6WD/West Coast Typically, one wheel is offset from the others to minimize resistance to turningRocking creates two 4WD systems, effectivelyTypical offset is 1/8” – ¼”Rock isn’t too bad at edges of robot footprint, but can be significant at the end of long arms and appendagesOne or two sets of omniwheels can be substituted for offset wheels.
9 Tracked  Pushing power increased Mechanically more complicated Need to have adequate track tensionThrowing a track and/or breaking one can be easy and very hard to fixSlower, much more power intensiveApplicationsHEAVY duty pushingClimbing
10 Omni/Mecanum Mechanically as complicated as a 4WD System A lot of times can substitute normal wheels for Omni/Mecanum in tight situations.Less pushing power, more maneuverableControl can be more complicated (especially with Mecanum)More parts that can break
11 Crab/Swerve  Extremely mechanically and program complex Lots of parts to make/buy/fixHighly maneuverableRequires (normally) precise engineeringTakes up a lot of space, uses a lot of motorsPure 4-Crab: 5Pure 4-Swerve: 8!
12 Other Information Steering vs. Drive Systems In FRC, there are no “Tank” Drive Systems. There is Tank Steering and Track Drive Systems. These terms are NOT interchangeable.Tank Steering:Uses 2 Joysticks, Left Joystick controls speed of Left motors, Right Joystick controls speed of Right motors.Arcade Steering:Uses 1 Joystick, controls speed of Left and Right motors together.
15 Homework1. Describe the Drive Train FRC Team #1208 (us…) used in the FRC 2010 Competition.2. Name 1 advantage and 1 disadvantage of using a Meccanum Drive System.3. What is the difference between Tank Steering and a Track Drive System?