Page 281 - Making things move_ DIY mechanisms for inventors, hobbyists, and artists

258 Making Things Move

The next step up in describing your part or mechanism is sketching your ideas on
paper. This helps you to plan things and get an idea of scale, and maybe of how
different parts will fit together. Most mechanisms, regardless of whether they’re
fabricated by hand or computerized machines, begin life as 2D sketches on napkins
and scrap paper.
You might also sketch in 3D. No, this doesn’t mean wearing 3D glasses while you
draw or standing your paper up against the wall. This means using reconfigurable
and/or disposable materials to visualize your ideas in three dimensions. LEGOs are
perfect for this, especially a LEGO set that has gears, motors, and a variety of other
components you can use to make simple machines. LEGO sells several simple
machines and motorized mechanisms kits that are perfect for this purpose. Some
universities have entire rooms filled with LEGO parts to aid in the prototyping stage of
creation. You can also use paper, popsicle sticks, straws, string, balsa wood, clay, hot
glue, or any other material that is quick to work with, so you spend time thinking in
3D and not refining your project—yet.

Digital Creation

The computer programs you can use to visualize your designs are collectively called
CAD programs. CAD stands for computer-aided design. But most of these programs
can do more than aid you. They can also create digital files that you can use to make
parts directly. We’ll talk more about fabrication from digital files later in the chapter.

NOTE Whether you are going to make parts by hand or have them made
by a machine, CAD software is still a handy tool to have in your prototyping
toolbox. A student of mine conveyed this idea well. After using Alibre Design
software to model a part in 3D that was later cut out of flat sheets of plastic,
he said, “I went and 3D modeled it anyway, because it’s really helpful for
visualization.”

The type of object you want to make will dictate the software you use and the type of
file you will create. Read on for tools for both 2D design, 3D design, and software
that lets you create entire assemblies of parts.