Page 232 - Making things move_ DIY mechanisms for inventors, hobbyists, and artists

210 Making Things Move

FIGURE 7-24 Attaching components to shafts

• Screw it If your component has a set screw hub, this is easy. If it has a plain
bore with a hub, you can drill and tap a hole for a set screw. If it has no hub at
all, you can make your own, or use an off-the-shelf mounting hub like the one
shown earlier in Figure 7-20.
• Screw and pin it If you can drill a hole radially through your shaft, and you
can drill a hole anywhere on the face of your component, you can probably
connect them with a stiff wire or pin. This is displayed in the right image of
Figure 7-24.

• Pinch-clamp it Use a shaft collar on either side of a flat gear or other
component to hold it in place. If you squish the shaft collar together while you
tighten their clamps or set screws, you can pinch the component as well. This
method is used in Project 10-2 in Chapter 10 to secure the wind turbine parts
that hold the blades.
• Hold-and-stick it Use epoxy putty to glue a shaft collar onto a flat
component (and/or the shaft) to create your own hub. This method is used
twice in Project 10-2 to secure the laser-cut gears to the wind turbine shaft
and motor shaft.

Using Clutches

A clutch is a special type of coupling designed to connect or disconnect the driven
part (shaft) from the driving part (motor), usually as a safety mechanism or to allow
motion in only one direction. Some clutches, like part MSCB-4 from SmallParts
(www.smallparts.com/), let you set the limit between where they slip or grip (see
Figure 7-25).