Page 418 - Hacking Roomba

Appendix A — Soldering and Safety Basics 399

Making the Solder Joint

If you want to use heat-shrink tubing, cut off an inch length and slide it onto one of the wires,
but out of the way for now. Move the two wires together so they touch. With the soldering
iron, lightly touch the two wires. Watch the solder on each flow together to form the joint as
shown in Figure A-18. You may find having a tiny bit of fresh solder on the iron helps this
process, but otherwise you shouldn’t need solder at this point. The solder joint is now done and
should be quite strong.

FIGURE A-18: Making the connection: notice solder is not needed.

Adding Insulation with Heat-Shrink Tubing

Slide the piece of heat-shrink tubing so it covers the solder joint and heat it so it shrinks down
and forms a tight fit around the joint. This not only insulates the joint from the elements and
electrical shorts. It also adds some mechanical strength to the area around the joint. You can
use a special heat-shrink gun or a lighter, but the most readily available source of heat is your
iron, so using the lower temperature side of the tip, wave the iron around the heat shrink tub-
ing and watch it shrink, as in Figure A-19. You’ll have to move all around the tubing to make
sure all of it shrinks. Figure A-20 shows the finished result.