Page 111 - Robot Builder's Bonanza

Chapter 8

Build a Motorized

Wooden Platform

ou read in the preceding chapter how to use wood to create robots. In this chapter you
Ycan put that knowledge to good use to build the PlyBot, a simple, affordable, and expand-
able robot base using just a small sheet of 1/4″ plywood. Only simple straight cuts are used.
You need to drill just six holes to mount the two motors and the ball caster.
The construction of the PlyBot requires no special tools. You need a saw for cutting the
wood and a drill for making holes. Plus: a screwdriver and small pliers for assembling the
pieces. Parts for the PlyBot are available online and at better- stocked hobby stores.

In the text that follows I provide the exact model numbers for the pieces you need. But remember
G that you’re free to substitute with something else if you already have it or if you’ve found
substitutes that are cheaper or easier to get. See also the RBB Online Support site (check out
Appendix A) for additional parts sources and alternatives.

Making the Base

Refer to Table 8-1 for a list of parts.
Figure 8-1 shows the completed PlyBot, with wooden base, twin gear motors, wheels, and
support caster. The robot measures 5″ 7″ overall. The base is constructed from 1/4″-thick
5- ply birch plywood and is driven by two Tamiya worm gear motors; the motors come in kit
form, and assembly takes 10 to 15 minutes for each motor. The wheels, also made by Tamiya,
securely lock onto the axles of the motors using hardware that’s included.
The “third wheel” of the PlyBot is a ball caster— more technically called a ball transfer, as
they are used on conveyor belts to literally transfer goods (boxes, palettes, machinery) through-
out a warehouse or factory. I used a ball caster/transfer from McMaster- Carr (www.mcmaster.
com), a large and well- known online industrial supply retailer. The caster costs under $5, and

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