CHAPTER 24 ■ BODY BUILDING
When you have a sense of the weight requirements and dimensions, the robot body’s characteristics are
clear enough that you can begin selecting materials and shapes that are likely to be sufficient. At this point,
you can either build a custom body that approaches your particular vision or you can select from existing
mass-produced bodies (whether designed for robots or not).
Designing Custom Bodies
The overriding philosophy of building a custom robot body is that the body is made to fit the robot, rather
than the robot fitting the body. If you’re a skilled or patient artisan with the proper tools and materials, a
proud and capable robot will result.
Plastic Prototyping—Constructing Models with LEGO Bricks
LEGO bricks are Scandinavia’s gift to robot builders. Honestly, they’re serious prototyping tools. Don’t let a
loved one knock you for playing with your LEGOs.
With LEGO bricks, robot designs can be invented, altered, refined, discarded, recovered, and ultimately
born. LEGO bricks hold together well under light to moderate loads. They’re readily available in a huge
variety of shapes, colors, and sizes. Although moderately expensive, their reusability and time-saving
qualities make them a worthwhile investment.
When first designing a robot for this book, I began with a pair of elegant Maxon motors and a pair of
homemade aluminum couplers (like the ones described a couple of chapters ago). With a box of LEGO
Technic bricks, gears, and tires, the basic frame was established (see Figure 24-1).
Figure 24-1. Prototype for Wavy, designed with LEGO bricks
Material Substitution—Transitioning Out LEGO Parts
Although LEGO frames can be instantly glued together with cyanoacrylate adhesive (super glue, aka
“kragle”), it’s more cost-effective to use materials other than LEGO bricks. Metals provide greater strength
and give the robot a rugged look.
With a marking pen, I traced the LEGO frame onto a stock piece of aluminum. I then cut out the
aluminum, sanded the edges, and drilled some screw holes (see Figure 24-2). This reduced the quantity of
LEGO blocks to two side bars for wheel and gear alignment.