Page 144 - Robot Builder's Bonanza

METAL FROM CRAFT AND HOBBY STORES 113

ucts. In Chapter 12 you’ll learn how to use some of these common and inexpensive tie plates
to make a sturdy metal robotic base.

STEEL TUBES AND ANGLES
Most hardware stores carry a limited quantity of extruded round and square tubes, as well as
angles and other shapes. These are solid and fairly heavy items made with 14- gauge steel. Use
them when you need lots and lots of support. Many are predrilled with holes along the sides,
saving you the effort. You still have to cut them, though. For cutting, use a hacksaw with a
new fine- toothed blade, as detailed later in this chapter.

EMT PIPE

EMT means electrical metallic tubing, often referred to as metal conduit or thinwall. It’s used
to enclose electrical wiring for a building— and sometimes to make robots. You’ll find it in the
electrical section of the hardware or home improvement store.
Conduit comes in a variety of sizes, starting with 1/4 and going up. The 1/2 and 3/4 sizes
are more common. Electrical conduit pipe can be used to make unusual robot frames. You can
bend it with a conduit- bending tool.

The sizes of EMT conduit is not in fractional inches, though it’s often listed that way in catalogs
G and stores. Depending on the metal used, EMT 1/2 (the 1/2 is called the trade size) is actually
0.622″ on the inside and 0.706″ on the outside. When shopping, bring along a tape measure
so you can be sure you’re getting the size you need.

In addition to the EMT pipe itself, other conduit- related materials are useful in robot con-
struction. Topping the list is the conduit hanger and clamp, like that in Figure 11-5. These
make good mounts for things like motors. You can almost
always find a conduit hanger or clamp that will fit a round-
shape motor— give it a bit of a squeeze or stretch if the size
isn’t perfect right off the bat.

Metal from Craft and

Hobby Stores

Hobby and craft stores are another handy outpost for your
metal needs. Sheets of stainless steel, copper, and even
bronze are common. Some of the metal products are
meant to be used for decorative purposes, so they’re very
thin and not as useful as structural parts in a robot. These
are more like thick aluminum foil than metal sheets. But
other, heavier pieces (22 gauge and above) are suitable for
Figure 11-5 EMT pipe clamps make for making bases and frames.
useful motor mounts on your robots. They Besides sheet metal there are metal strips, bars, and
come in plastic or metal, in various sizes and tubes, both round and square. The tubes are sized so that
styles. they “telescope”—they fit within one another. You might

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