Transcript VEX Drive Trains BMT Revised

VEX Drive Trains
Drive Trains
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Vocabulary
Skid Steering (Tank Drive)
Swerve Drive
Holonomic (Omni Drive)
Mecanum Drive
Drive Train
A robot’s drive train consists of all of the
components used to make the robot move.
– Motors
– Wheels
– Gears
Motors
Motors make attached
axles spin at a set
speed.
Perfect for wheels and
gears.
Motors can’t turn to an exact position.
Standard Motors (269)
• standard motors
• light weight
• batteries last longer
High Strength Motors (393)
• give 30% more torque or 30%
more speed (if you change the
internal gears)
• heavy
• reduce battery life
J.M. Gabrielse
Command
Joystick
Motor
Forward
(+127)
Neutral
(0)
Backward
(-127)
J.M. Gabrielse
Tank Drive
The left and right
sides of the robot are
powered by different
motors.
Each wheel of the
Simplebot is directly
connected to a
motor.
motor
motor
motor
motor
Simplebot Base
X-Wheel Drive
X = 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 protobot has only two motors, but it is an
example of four wheel drive since all four wheels
are connected to motors.
Skid Steering
(Tank Drive)
To turn, one side goes
forward and the other
goes backwards.
Wheels
High Traction Rounded Tread
• These wheels include a
smooth “grippy” tire
which has high traction
on smooth surfaces.
High Traction Square Tread
• These wheels include a
tire which works well on
any surface.
High Traction Rough “Knobby” Tread
• These wheels include a
“knobby” tire which
works great on rough
terrain or loose
surfaces.
Omni-Wheels
• Rollers around the
edges allow omniwheels to roll sideways
The 4” omni-wheels are in your kits. The 3” onmi-wheels are not included.
Swerve/Crab Drive
A swerve drive robot has the ability to rotate its wheels.
Holonomic (Omni) Drive
Omni wheels
pointing in
opposite
directions allow
the robot to move
in any direction or
spin.
Mecanum Wheel
Mecanum wheels allow
savvy robot designers to
create drive trains capable
of moving in any direction
using a standard chassis
shape.
Simply power each wheel
with a different motor and
by changing the directions
the wheels spin get your
robot to move in any
direction!