Page 285 - Making things move_ DIY mechanisms for inventors, hobbyists, and artists

262 Making Things Move

Using assemblies also allows you to download CAD files of all kinds of off-the-shelf
components directly from McMaster and other vendors. You can then assemble them
on your screen before buying anything, so you make sure everything fits together
perfectly. With 63,000 component CAD files currently available on McMaster alone,
this can save you a ton of time.
Assemblies allow you to visualize what your final mechanism will look like, while
keeping the part files separate from each other. This way, one part can represent an
off-the-shelf motor, another part can be exported for 3D printing, and another can be
made into a drawing to send to a laser cutter.

roject 9-1: Download and Open a 3D Model
Pof a Part

Of the programs listed in Table 9-1, only a few include the built-in ability to make
assemblies of parts: SolidWorks, Autodesk Inventor, Pro/ENGINEER, and Alibre Design
Personal. Let’s step through an example using the most affordable option: Alibre
Design. Alibre’s mission is “... providing full parametric CAD technology to anyone
that needs it, versus only to those in the relatively unique financial position to afford
traditional CAD systems.”

Recipe:

1. Download Alibre Design from www.alibre.com. It starts with a free 30-day trial
of the Pro version, and then you can choose to purchase the Personal edition
(currently $99) to maintain functionality.

2. Go to the McMaster site (www.mcmaster.com) and find the part you want to
download. As shown in Figure 9-2, I chose a standard 1/4-20 by 1 in long
stainless steel socket head cap screw (92196A542). Check in the sidebar to
see if 3-D Model is an option (if not, find another part that does have this
option).

3. Click 3-D Model, and you’ll get a drop-down menu that gives you options of
3D models or 2D technical drawings to download. Choose 3D STEP, IGES, or
SAT—all of these work with Alibre Design. Download the part and save it
somewhere you’ll remember.