Page 337 - Robot Builder's Bonanza

306 BUILD ROBOTS WITH WHEELS AND TRACKS

Figure 26- 8 Completed RoverBot,
constructed using only straight cuts. You
can use wood, plastic, or metal for the
body pieces. See the RBB Online Support
site for full plans on constructing the
RoverBot.

USING MORE EFFICIENT MOTORS
The Tamiya Twin- Motor kit makes for an affordable and easy- to- use motor set for small
desktop robots, but these motors are not terribly efficient, and they consume a lot of
current.
You can replace the DC motors used in the twin- motor kit with more efficient ones. The
gearbox kit uses a pair of Mabuchi FA- 130–size motors. You may substitute for a more effi-
cient motor, as long as it conforms to the “130” motor size. Pololu and several other online
sources offer replacement 130- size motors that consume much less current than the stock
units that come with the Tamiya kit.

Bonus Project: Double- Decker RoverBot

Figure 26- 8 shows a double- deck tabletop robot that I’ll call RoverBot. This base requires only
rudimentary construction skills (straight cuts only) and can be made using a number of materi-
als, including 1/4″-thick aircraft- grade plywood, 1/4″-thick expanded PVC sheet, or 1/8″
acrylic plastic. It’s designed to be easy to build and easy to expand.
This is a free bonus project available on the RBB Online Support site (see Appendix A).
On the support site you’ll find complete construction plans, including cutting and drilling lay-
outs, parts list and sources, and assembly instructions.

Building 4WD Robots

What’s better than a two- wheeled robot? Why, four wheels, of course! Four- wheel- drive
(4WD) bots are able to traverse more kinds of terrain than their two- wheeled cousins, moving
from indoors to out with ease. They’re the preferred method of exploring grassy or dirt
areas. And because they have four wheels, 4WD robots are statically balanced and have no
need (or use) for a caster. Like a 2WD robot, 4WD bases use differential steering to explore
their world.

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