Build Your Own Combat Robot

Soldering Wires
Appendix A: Prototyping Electronics 339
Many wires are used in robot construction to run from control circuitry to motors
and sensors. You should always use stranded conductor wire as opposed to solid
conductor wires. The many strands allow for better flexibility and greater current
carrying capacity. Before soldering the wire, strip a small amount of insulation
from the wire—an amount appropriate for the particular connection.
Twist the strands slightly with your fingertips so they are held together in a
slight spiral and are not splayed out. Then tin the wires with a bit of solder before
soldering the wire onto a connection. To tin the wires, tin the soldering iron’s tip
with an excess of solder and place the heated ball of solder on the tip against the
bare wire strands. As the wire heats, the solder should be sucked into the strands
as you add a bit more solder. Again, too much heat can damage the wire, or at least
melt or burn the insulation. Practice makes perfect.
Soldering Connectors
Connectors are used in many places on large and small robots. They connect many
wires to your control modules, receivers, drivers, sensors, and many other items.
Most connectors have a series of pins in rows or circular patterns. The pins usually
have small cavities behind them into which wires are soldered or crimped. As always,
you don’t want to overheat the pins to damage the connector, but each of
the pins should be tinned with a bit of solder, as should the wires to be inserted.
While applying heat to the back of the pin, slowly insert the tinned wire, taking
care not to have one or more strands splay out. Do this with each wire until completed.
As always, practice makes perfect.
When soldering the larger wires used in combat robots and other large machines,
the use of a soldering gun helps a lot. Tinning large wires that are used in
terminal lugs is recommended, as more surface area of the wire is in contact with
the barrel of the terminal lug, thus reducing resistance and allowing more currentcarrying
capacity. A large soldering gun or small torch can be used to solder copper
and brass sheeting and tubing, both to each other and to wires.
Caution Remember, good soldering takes patience for the best results. Be careful not to
allow drips of solder on your clothes. For obvious reasons—it burns; but it’s also impossible to get it
out of some fabrics without burning (melting) it out.
C rimp-Style Connectors
When working with any high current wiring that is subject to vibration, it is best
to use crimp style connectors that screw into components such as electronic speed
controllers and batteries, and terminal blocks. Soldered joints will eventually fail
if the wires are allowed to vibrate. Make sure you use the right connector size with
wire the gauge you are using. It is best to use the connectors that have round holes
in them. The “forked”–shaped connectors should be avoided. This is because if