doesn’t have to look pretty, and it
doesn’t have to last. Just carve out a
circle, square, or other shape, then
poke holes through it to mount
motors, battery holders, and
electronics; then set your robot on the
floor to test your ideas.
You can even adapt other
temporary construction techniques to
speed the R&D of your robots. For
example, double-sided foam, wire
tie-wraps, and other temporary
fasteners can be used instead of
traditional screw and nut fasteners.
Though often useful to test out
ideas, foam board can also be used
for permanent construction, as long
as the components of your bots are
lightweight and the demands for
accuracy aren’t high.
Consider this kind of construction
for projects for small kids. Have an
adult cut out and drill the bases. Foam
core parts are easily replaced and cost
just pennies.
Lastly, there are foam board
products that use very thin pieces of
plastic instead of heavy paper in their
lamination. The plastic surrounds a
foam usually denser than in the paper
variety. This type of foam board is
useful as well, but not quite as easy to
work with.
Art and Sign Making
Substrates
Foam board is often considered a
substrate for creating something else.
Sign makers use substrates like foam
boards as something to print on.
There are many types of substrates for
signage, including wood, plastic,
metal, foam, and glass. Sign maker
suppliers sell these substrates in
convenient sizes and in many colors.
Many of the substrates can be used
to fashion all kinds of robot parts,
including bases, frames, and bodies.
Here’s a sampling of sign making
substrates that can also be used in
robots. I won’t spend a lot of time
discussing each one; you’re best off
seeing what’s available in your area
and personally inspecting a sample.
Many of the items I’ll mention are
specific products that go by a specific
name. It’s unlikely you’ll find a
supplier that has everything. Check
in your local Yellow Pages for plastic
retailers and sign making shops,
and see what alternatives are available
to you.
MDO plywood — MDO stands
for Medium Density Overlay, a lighter
Look for the WireMesh sculpting product on the Amaco.com website.
weight plywood than stuff at the
lumber yard, yet still very strong.
Alumalite — Aluminum over
corrugated plastic; thicknesses from
1/8 inch; very strong stuff! Note this
is a different material than Alumilite
which is a casting compound.
Clad-tex aluminum sign blanks
— Variations on an aluminum theme
with plastic, vinyl, and other coatings
over aluminum sheet.
PVC board — Expanded (foamed)
PVC; this is the basic stuff you
shouldn’t be without. Brand names
include Celtec, Sintra, Komacel,
and Komatex.
Corrugated plastic — Goes
by trade names like Gatorboard,
Gatorplast, and other Gators; looks
like the liner in cardboard but is made
of plastic.
DiBond — Sheet metal over
expanded (foamed) PVC; economical
alternative to Alumalite.
Econolite — Like Alumalite, but
with aluminum on one side only.
Fiber-Brite substrates —
Fiberglass panels; very light but
very strong.
PolyCarve substrates —
Extruded polyethylene that can be
carved into 3D shapes.
Reflective tapes — Metal or glass
tapes that reflect lots of light.
Holographic tapes and films —
Add rainbow colors and designs with
various patterns.
LusterBoard — Aluminum on
the outside, lightweight wood on
the inside; 1/4 and 1/2 inch widths
common.
Prices for these materials can be
very competitive because sign makers
get paid by the job and they want to
reduce their materials costs as much
as possible. On the other hand, online
retailers of sign making supplies may
require a minimum order of $25 or
$50, and some will not cut material to
more convenient sizes — typical sign
substrate sheets are 4 by 8 feet.
Not only do you get a big sheet of
material to contend with, it must be
shipped via motor freight and not
UPS. Because of added expenses
of trucking, look for sign maker
60 SERVO 05.2009
