44 SERVO 07.2015
often surprised by how much information is available to
assist me in my projects. Articles, forum threads, and even
videos detailing the work of others can speed up your
design process and keep you from having to continually
recreate the wheel.
When doing your research, be sure to bookmark any
interesting discoveries even if they don’t directly relate to
your current project. A future project may benefit from
something you came across months ago. These currently
unrelated tidbits may also trigger new building ideas.
Has Anyone Seen My Drill?
There are many steps to complete before you ever start
building. Take stock of the tools you have on hand and
decide if you need to purchase or borrow any. When just
starting out, this can add a substantial amount to the cost
In addition to the basic hand tools, the instrument I
find the most useful is my rotary tool. The wide
assortments of accessories available make it an invaluable
prop building partner. Whether I’m fabricating brackets for
an armature, cutting aluminum, or removing material from
a plastic skull, it’s my primary tool choice. I have one
permanently plugged in and hanging above my bench with
a flex shaft installed, and a battery powered version in its
charger for when I am working outside.
Sitting right next to my Dremel are my two battery
powered drills. Having one for drilling and another with a
screw or nut driver installed greatly speeds up my work
flow. Have a good assortment of sharp bits close by, as
Another useful addition to my toolbox is a hot glue
gun. I know what you’re thinking. How can hot glue
successfully stand up to the repeated stresses put on our
creations? Well, you’d be correct. The primary use I have
for my hot glue gun is when I am putting together the
initial prototype. It provides a quick, fairly sturdy bond that
allows me to test a variety of configurations before
committing my build to more permanent materials. You can
easily break the bond if required, or dissolve it with a shot
of rubbing alcohol.
Owning a soldering iron and knowing how to use it will
certainly be something you’ll want to be comfortable doing.
Whether it’s extending the wires that provide power to your
design or soldering up a circuit board that will control it,
sooner or later you’re going to need to know how to
solder. There are plenty of good tutorials on You Tube, and
I’ve included my favorite with the other resources. (SERVO
had a recent tutorial on Basic soldering techniques that
wrapped up in the June 2015 issue.)
When selecting your initial project, start small. It’s very
tempting to try a really cool but complicated project, and
then get discouraged when it doesn’t turn out as expected.
Select a project that utilizes your current skill set so that
you maximize your chances for a completed first project.
Nothing builds confidence like success!
A good assortment of different building materials also
makes the process proceed smoothly. The following
materials are the ones I most frequently reach for. We’ll go
over the pros and cons of all of them and look at the
situations where each may excel.
Time to Get Started
You will need to determine what building materials you
will utilize to construct the actual armature. Things to
consider include strength, weight, rigidity, cost, durability,
and ease of use. Safety always come first. So, if in doubt,
Foam core is a great medium for prototyping and
experimenting with different designs. It’s cheap and easy to
cut and work with, yet provides sufficient strength to do
some light testing of your basic build concept.
Although plastic pipe can be used for some lightweight
builds when only minimal torque is being exerted upon the
structure, I primarily use it for prototyping. The pipe and
fittings are inexpensive and easy to find at your
neighborhood hardware store. It is very easy to work with
and to make adjustments on-the-fly. However, it’s not very
rigid or strong, so think long and hard before deciding to
include it in your final build. Remember that your build is
only as strong as its weakest link. I have used it successfully
in a project using a low torque motor, and took advantage
of the low rigidity to add a little extra movement.
I prefer to use the gray electrical conduit versus the
white plumbing pipe as it is a little cheaper and it comes
with a coupler built into the end. All of the plumbing
fittings will work with the electrical conduit, as well.
If you are going to use plastic pipe in your final
assembly, you will need to make solid connections. The
traditional method is to glue the joints together but I prefer
Post comments on this section and find any associated files and/or downloads at
ServoCity — www.servocity.com/
Monster Guts — http://monsterguts.com/
Spider Hill Prop Works — www.spiderhillpropworks.com/
McMaster Carr — www.mcmaster.com/
Fright Props — www.frightprops.com/
RobotShop — www.robotshop.com/
SparkFun — www.sparkfun.com/