48 SERVO 07.2015
speed when they extend and another rate when they retract.
When getting started using pneumatics, you may want
to consider buying a kit to insure all the components will
work together. I’d suggest getting one that uses a five port
four-way solenoid as they are the most versatile. You can
always plug up ports that aren’t needed, but it’s nice to
have the option.
Additionally, when purchasing cylinders, I always go
with the double-acting cylinders since air pressure may be
alternately applied to provide force in both directions. They
do use more air than single-acting cylinders, but the added
flexibility is worth the trade-off.
You’ll need to select the mounting style, as well. You
can get models with specific mounts, but I prefer to get
them with a rear pivot version. This gives me the maximum
adaptability when used in conjunction with a clevis
attachment on the cylinder rod.
Finally, you’ll need to decide whether to use AC or DC.
As with the motors, I prefer to go with 12 VDC, but they
are also available in 24 VDC or 110 VAC.
When purchasing components, I try to consider not
only the requirements for the current project but plan for
the usefulness of my components in future builds. I’m
constantly dismantling creations that I no longer use and
reusing the parts, so this will save me time and money
down the road.
There’s no magic here, but getting all the correct
pieces the first time can be intimidating. Once you
assemble a kit and get comfortable working with an air
system, you’ll know what to order for your next project.
That’s Not What I Want to Do!
You’ve decided on a design, picked the materials to
use, and chosen the proper device to make it move. You’ve
labored in your shop to bring your creation to life.
Congratulations! You’ve completed your first build. It’s
time to power it up and enjoy your success, right? Well,
maybe. Oftentimes, the resulting motion is not what you
planned when you worked it out in your head.
Don’t be discouraged if it takes a substantial amount of
tweaking and modifying to get the result you want. I seem
to spend more time on this stage than any other during the
build process. It’s all part of the fun!
The design and construction of animatronic props and
characters can be a very rewarding and challenging
undertaking. Hopefully, I’ve been able to convince you to
give it a try.
Your creations can be as simple or complex as you
desire, with each completed project adding to your
confidence and skill sets. So, pick a project and get moving!
Figure 8. Vent motor which uses magnets to move a Ouija
board planchette back and forth.
Figure 9. Waving Santa. See him in action at