Page 225 - Making things move_ DIY mechanisms for inventors, hobbyists, and artists

Chapter 7 Bearings, Couplers, Gears, Screws, and Springs 203

Couplers
A coupler, or coupling, is anything that joins two rotating things to transfer torque
from one to the other. Attaching, or coupling, something to your motor’s shaft can be
the first and biggest challenge you face when building your mechanism. Information
about how do to this is rarely rounded up in the same reference. The methods depend
on the motor type and shaft shape. The following sections summarize recommendations
from different sources and years of experience, so you can easily see your options for
extending a motor shaft, attaching it to an existing shaft, connecting it to a gear, and
so on.

Working with Hobby Servos

Hobby servos make connecting anything to them very easy because they come with a
spline (a little gear-shaped thing) already fixed to the motor shaft (see Figure 7-16).
All the hardware designed to interface with servos has the female indent of the spline
already in the part, so it just slides on, and then is usually secured with a screw into
the motor shaft itself.

FIGURE 7-16 Servo motor with spline on motor shaft and extra attachments