An Endless Parts Library
The third — and final — caveat for printing instant robot
parts is actually the most important point of all. Regardless
of your 3D printer model or your printing control interface,
you still need a comprehensive source of 3D robot part
CAD files to print. There are four prime sources for these
files:
1. McMaster-Carr. At mcmaster.com, the bulk of its
fastener catalog is available as STEP files.
2. SparkFun Electronics. At sparkfun.com, a
methodical conversion of their PCB (printed circuit board)
plus (some) parts in their product line are made available in
several 3D model formats including STL.
3. Actobotics (ServoCity). At servocity.com, the robot
parts mother lode can be downloaded as STEP files (see
Figure 8).
4. Honda Motor Company. At honda-3d.com, some
robots look like cars (e.g., Google self-driving car); this is a
great source of high-resolution STL files.
Not every part will print perfectly for “drop-in”
replacement. You might need to tweak a 3D model for
helping it to fit properly in your project.
As a general rule of thumb, here are two easy tweaks
that could solve most of your fit problems (or, is that
problems that are giving you fits):
• Parts that have to fit inside another part; a threaded
Figure 8. High quality aluminum channel versus low quality
"draft" mode HIPS channel.
Figure 9. Fasteners can be threaded in HIPS models.
48 SERVO 01.2016
