30 SERVO 01.2016
you purchase inexpensive cutters designed for it (Figure 5)
which are available at any big box hardware store (see
Resources). It will speed up the process considerably. PVC
can also be shaped by heating it with an inexpensive heat
gun. Using this method allows you to customize the
structure of your character in ways not attainable using
only the available fittings.
This is a good time to figure out the placement of your
motors, servos, or cylinders. Make sure that your creation
has the space to mount the necessary mechanisms. You will
also want to consider the placement of the electronics. Will
they be located inside the body or will they be situated
outside with wire extensions to the motors? One thing I
always try to mount inside the bodies of any talking props
is the speakers. I install them as high in the chest as
practical to put the audio as close to the mouth as I can.
This makes it more believable, as well as helps to cover the
sound of the motor that is driving the jaw.
One product that I use extensively for my prototypes is
an adjustable and locking joint from Spider Hill Prop Works
(Figure 6). These allow me to fine-tune the joint angles and
get things dialed in exactly as I want them. Deciding on the
precise design — especially if your final design will be
welded steel — will save a tremendous amount of time and
frustration later (see Resources).
Now that I have constructed my prototype, I can finally
start to work on the actual build. This is the fun part as you
watch your idea finally come to life! Hopefully all the effort
you put forth during the planning process will lead to a
smooth build. Expect that no matter how well you have
designed your character, it will surely require some
tweaking. It seems that I still spend the majority of my build
time on this step. Little adjustments are always needed to
get things to work perfectly! With all the time you have
spent to get to this stage, you do not want to shortchange
The electronics that bring your creation to life are, of
course, a vital part of the build, but we lack the space to
cover it all in this article. It deserves its own article which
will be coming soon, so be sure to watch for it.
Brian’s Steps to Success
In contrast to the system I use when planning a
project, we will take a look at Brian’s approach now. While
I do spend a reasonable amount of time planning my
builds, Brian’s approach is much more comprehensive.
In order to feature Brian’s process, we will be looking
at one of his recent projects. Brian was part of a team that
was developing an elaborate display for a local event. The
original concept included a lighted flying saucer with an
alien hand appearing from an opening dome structure.
Brian has taken great pains in completely documenting the
entire process in his thread at http://tinyurl.com/
Figure 5. A PVC cutter is a real timesaver.
Figure 6. Spider Hill Prop Works adjustable joint.
Figure 7. Foam and cardboard mockup.