PART 1: by David A. Ward
FIGURE 2.
FIGURE 1.
FIGURE 3.
If you’re looking for a way to add muscle to your robots,
then as Bob Dylan would say, the answer may be may be
blowin' in the wind in the form of compressed air and
pneumatic controls.
I have wanted to incorporate pneumatics into some of
my personal projects and (as an instructor) into my industrial
control systems course for some time now, but wasn't
sure where to begin. Pneumatic trainers are available for
classroom instruction, but the ones I have checked into cost
anywhere from $3,500 up to nearly $20,000. I recently came
across a great website and article, "A Pneumatic Tinker-Toy
FIGURE 4.
Set for the Home Imagineer" at www.phantasmechanics
.com/air/ air2.html which pointed me in the right direction.
This article listed pneumatic part numbers from Grainger
Industrial Supply and showed how to interconnect them.
Another good resource is Basic Pneumatics: An Introduction
to Industrial Compressed Air Systems and Components, by
Jay F. Hooper (ISBN 978-0-89089-119-3).
Pneumatics can offer some great muscle for projects at
a much lower price, lower weight, and simpler design than
using electrical components to accomplish the same task.
While the nearly $200 price tag for the system shown in
this article may seem high to the hobbyist, it appears quite
reasonable when compared to the commercially available
pneumatic training systems I have looked into.
This first article will show the reader how to set up a
simple pneumatic, double-acting cylinder and pneumatic
control circuit that can exert a great deal of force at a very
rapid speed, if necessary. The second article will demonstrate
how to add electronic controls. This circuit can be controlled
with 24 VDC and therefore lends itself to electronic and
computer control.
To begin with, let's look at the basic pneumatic
components that will be needed for this introductory system
(see Photo 1). The system output consists of a double-acting
pneumatic cylinder that has a 3/4" diameter piston inside that
can travel 6" (see Photo 2). It is a double-acting cylinder
which requires air pressure to be applied to either end to
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