Page 179 - Robot Builder's Bonanza

148 RAPID PROTOTYPING METHODS

What follows applies to consumer- grade tape, Velcro, and other products. If you can get
your hands on the industrial- grade stuff, it’ll work the same but will give you greater holding
power. Naturally, it’s harder to find, more expensive, and often available only in bulk. Try
specialty industrial suppliers, such McMaster- Carr.

Don’t forget you can use regular machine screw and nut fasteners with rapid prototypes.
G Assembly can still be fast, especially when you use a motorized screwdriver. A word of advice:
When using cardboard, foamboard, and other soft substrates, add flat washers on both sides of
the fasteners. This helps prevent the screw and nut from popping through the material.

HOOK- AND- LOOP FASTENERS
Velcro was discovered when its inventor noticed how burrs from weeds stuck to the fur of his
dog. The construction of Velcro is a two- part fabric: one part is stiff (the burrs) and the other
soft (the dog). Attach them together and they stick. The term “Velcro” is a combination of the
French words “velour” and “crochet.”
Velcro is a trade name for a kind of hook- and- loop fastener, and the Velcro company
probably sells more of it than any other. It’s available in a variety of sizes and types, from
ordinary household Velcro you already know about to heavy- duty industrial strips that can
support over 100 pounds. Figure 14-2 shows some Velcro in action on a robot. It’s being used
to mount a wheel caster.
Among the most useful hook- and- loop products is the continuous strip, which you can cut
to the desired length. The strip comes in packages of one foot to several yards, in any of a
number of widths, with 1/2″ and 1″ wide being the most common. The strips come with a
peel- off adhesive backing. If the adhesive is not strong enough (which is sometimes the case),
you can reinforce the material with a heavy- duty epoxy, screws, staples, or the like.
While Velcro may be the best- known hook- and- loop material, it’s not the only kind. A great
alternative— sold in the tool department of many department stores— is 3M Dual Lock (see
Figure 14-3), a unique all- plastic strip that is composed of tiny plastic tendrils. Dual Lock has
no separate “hook” and “loop” components. It sticks to itself.

Figure 14-3 3M Dual Lock is an all- plastic version
Figure 14-2 Temporarily attach parts to your of the venerable hook- and- loop material. It’s available
robots using hook- and- loop (Velcro) fabric. Get the in different thicknesses, with or without self- adhesive
heavy- duty kind for holding larger components. backing.

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