Page 269 - Making things move_ DIY mechanisms for inventors, hobbyists, and artists

Chapter 8 Combining Simple Machines for Work and Fun 247

• Reciprocating Back-and-forth motion in a straight line.

• Intermittent Motion that starts and stops in a regular, predictable pattern.
• Irregular Motion with no obvious pattern or that doesn’t fit into the other
categories.

To use the table, locate the input motion you want on the top and the output motion
you want on the left side. The box where they intersect shows your options for doing
the conversion. (Much of the material in this table is from www.flying-pig.co.uk/
mechanisms.)

We’ve already talked about the more general methods: gears, pulleys and belts,
sprockets and chains, levers, cranks, linkages, and so on. The following are some of
the trickier conversions shown in Table 8-1:

• Scotch yoke Used to create linear and reciprocating motion from an
oscillating input (see Figure 8-10). Using a scotch yoke is an excellent way
to convert the oscillating motion of a servo arm to linear motion.

FIGURE 8-10 Scotch yoke in running of the bulls (CC-BY-NC-SA image
used with permission from Greg Borenstein and Scott Wayne Indiana)