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VEX Drive TrainsVEX Drive Trains

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Drive Trains

• Vocabulary• Four Wheel / Six Wheel• Skid Steering (Tank Drive)• Swerve (Crab) Drive• Holonomic (Omni) Drive• X Drive• H Drive & U Drive• Mecanum Drive• 2 Speed Transmission

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Drive Train

A robot’s drive train consists of all of the components used to make the robot move.

– Motors– Wheels– Transmissions

(gears / sprocket & chain)

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Motor

VEX 2-Wire Motor 393•The 2-Wire Motor 393 is the primary actuator used in the VEX Robotics Design System. Build rotational mechanisms, drive bases, rotational joints, conveyor belts - anything that spins can be built using the 2-wire Motor 393.•Strong, steel internal gears.•Can be configured into a "high speed" version.•The 2-Wire Motor 393 does not have an internal motor controller.

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Wheels

VEX has the right tire for any terrain. Here are different size wheel diameters (2.75“, 4“, 5") are available each with a different tread type; choose the perfect wheel for your application.

5" Wheels

4" Wheels

2.75" HighTraction Wheels

Intake Rollers

4" High Traction Tire

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Omni-Directional Wheels

4" Omni-Directional Wheel

Omni-Wheels roll forward like normal wheels, but slide sideways with almost no friction (no skidding during turns). Use these wheels to make your robot turn smoothly or build a holonomic drivetrain.

2.75" Omni Directional Wheel

2.75" Omni Directional Wheel

3.25" Omni-Directional Wheel

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Special “Wheels”

Intake Roller

6" Wheel Leg

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Gear Types

standard gears

differential bevel gears rack & pinion worm gear

high strength gears

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Sprockets & Chains

Standards Sprockets & Chains

High Strength Sprockets & Chains

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Four Wheel / Six WheelSquarebot (4-wheeldrive)

6-wheeldrive

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n-Wheel Drive

n = how many wheels are connected to motors

• Two wheel drive: two wheels are powered• Four wheel drive: four wheels are powered

How many motors the robot has doesn’t matter:

• The squarebot has only two motors, but it is an example of four wheel drive since all four wheels are connected to motors.

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Squarebot

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Skid Steering(Tank Drive)

The left and right side of the robot are independently powered.

To rotate, one side goes forward and the other goes backwards.

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Swerve/Crab Drive

A swerve drive robot has the ability to rotate its wheels.

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Omni-Directional (Omni) Driveaka Holonomic Drive

Omni wheels pointing in opposite directions allow the robot to move in any direction or spin.

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Omni-Directional (Omni) Driveaka Holonomic Drive

A drivetrain that can move in any direction at a given moment, without waiting for wheels to steer is called an Omni-Directional Drivetrain. These drivetrains use special wheels, called “omni-wheels”. Omni-wheels are wheels with small rollers around the perimeter that freely spin perpendicular to the wheel’s rolling direction. This means that the wheels can slide sideways with very low friction.

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Omni-Directional (Omni) Driveaka Holonomic Drive

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Omni-Directional (Omni) DriveThis is a true holonomic drive aka X Drive.

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H Drive & U DriveOther holonomic drives

U formation U formation

Four Wheel Drive Square Robot

Two Wheel Drive Square Robot

H formation

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Train Drives

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Mecanum DriveThe Mecanum drive is also a holonomic drive.

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Mecanum Holonomic Drive in Action

A VEX robot with a holonomic drive.

If video do not play, go to this link:https://www.youtube.com/watch?v=pP8ajNMx84k

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2 Speed Transmission Drive

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2 Speed Transmission Drive

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VEX Drive TrainsVEX Drive Trains

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