Page 214 - Making things move_ DIY mechanisms for inventors, hobbyists, and artists

192 Making Things Move

FIGURE 7-3 Radial bushings (credit: McMaster-Carr)

You can also find plastic and metal sleeves that have less friction than a drilled hole in
a block of wood does, but aren’t quite as frictionless as ball bearings. We’ll call these
radial bushings (see Figure 7-3).

Radial Ball and Roller Bearings
Your basic roller-skate bearing is a radial ball bearing and is by far the most popular
type. It’s easier to understand and find bearings for your projects if we go over a bit of
bearing anatomy and vocabulary first (see Figure 7-4).

FIGURE 7-4 Bearing anatomy

Width
Outer diameter

Outer race
Ball

Inner race
Inner diameter/ Cage/separater
bore size (optional)