Robot Builder’s Sourcebook

+ Actuators
Actuators are mechanisms that produce motion from
some energy source, such as electricity or air pressure.
Common actuators are electric motors and air cylinders.
Actuation mechanisms are used to control how
that motion is applied.
The companies in this main section make, distribute, or
sell a very broad line of actuators and mechanisms and
are listed here as generic resources. Additional companies
and resources are listed in the following subcategories:
Locomotion Systems
Actuators 1
Actuators-Motion Products: Specializes in
mechanisms (though may also sell motors and
other components)
Actuators-Motors: DC geared and nongeared
motors, servomotors, stepper motors (but not
motors for radio-controlled models)
Actuators-Other: Mechanical actuators (e.g.,
solenoids) that don’t neatly fit elsewhere
Actuators-Pneumatic: Air cylinders, control
values, pumps, and other fittings
Actuators-Shape Memory Alloy: Material
that contracts when heat or electricity is
applied.
Mobile robots use wheels, tracks, or legs to move around—there are exceptions, of
course: some snake-like robots crawl. We'll just concentrate on the usual designs.
Wheels: The Primary Moto-vator
Wheels are by far the most popular method of providing
robot mobility. Wheels can be just about any size, from an
inch or two in diameter to over 10 or 12 inches. Tabletop
robots have the smallest wheels, less than 2 to 3 inches in
diameter. Wheel size is critical for smaller 'bots because
larger wheels weigh more. Robots can have just about any
number of wheels, although two is the most common. In a
two-wheel robot, the machine is balanced by one or two
casters on either end.
Legs: I'm Walkin' Here, I'm Walkin'!
More and more amateur robots have legs. Legs are often
preferred for robots that must navigate over uneven terrain.
Most amateur robots are designed with six legs, which
affords static balance—the ability of the robot to be balanced
at all times because a minimum of three legs (in tripod
arrangement) are touching the ground at any one time.
Robots with fewer legs must take more careful steps, or
use dynamic balance (shifting of weight) to keep from falling
over.
Tracks: O' My Tears
Wheeled robots are the most
popular.
Despite their looks, six-legged
walking robots are not difficult
to build.
Tracks (or treads) are similar to what tanks use. The tracks, one on each side of the
robot, act as giant wheels. The tracks turn, and the robot lurches forward or backward.
Track drive is best for robots used only outdoors and only over soft ground, like dirt.
Copyright 2003 by Gordon McComb. Click Here for Terms of Use.