Page 406 - Robot Builder's Bonanza

USING HEADERS AND CONNECTORS 375

GOOD!

Not so good
Figure 30- 10 Good and not- so-
good examples of soldering. When
soldering components to a circuit
board, be sure the parts are in fully
and straight.

• When the joint is complete and has cooled, test it to make sure it is secure. Wiggle the
component to see if the joint is solid.
• Be sure to insert the component completely though the circuit board, and check that it isn’t
crooked (see Figure 30- 10). Excessive component lead length can cause short circuits if
they touch other exposed parts of the board.

SOLDER TIP MAINTENANCE AND CLEANUP
As the soldering tool comes to temperature, clean off the tip by wiping it against a damp
sponge. As you work, periodically repeat this step to keep the tip free of excess solder.
The tip should always be tinned, meaning it should have a very light coat of solder on it.
Tinning involves cleaning off the tip with the damp sponge, then directly applying a bit of
solder to the tip (this is one instance when applying the soldering tool directly to the solder is
allowed). Remove any excess solder by wiping again with the damp sponge.
After soldering, let the tool cool down for at least 10 minutes before putting it away.
After many hours of use, the soldering tip will become old, pitted, and deformed. This is a
good time to replace the tip. Old or damaged tips impair the transfer of heat, and that can
lead to poor soldering joints. Be sure to replace the tip with one made specifically for your
soldering tool. Different brands of tips are generally not interchangeable.

Using Headers and Connectors

Most robots are constructed from subsystems that may not be located on the same circuit
board. So you need to connect these subsystems together using some kind of wiring system.
For very simple connections, you can directly solder wires between boards and other compo-
nents. But as the electronic systems of your bot get more complex, such direct connections
make it harder to experiment.
The solution: Use connectors whenever possible. In this approach, you connect the various
subsystems of your robot together using wires that are terminated with a connector of some
type or another. The connectors attach to mating pins on each circuit board.

MAKING YOUR OWN MALE CONNECTORS

You don’t need fancy cables and cable connectors for your robots. In fact, these can add sig-
nificant weight to your bot. Instead, use ordinary 20- to 26- gauge wire, terminated with single-
or double- row plastic headers.

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