28 SERVO 09/10.2018
tough nylon-like material (Figure 5). If they prove successful,
I’ll make them available to the public through Shapeways.
The design assumes the use of aluminum screws for
many of the joints. I searched on the Internet and found
what I wanted (Figure 6). Hopefully, they’ll prove tough
enough for this application.
On the plus side, they are fairly
large screws for so small a bot (makes
assembly and repair easier), so perhaps
they’ll work out fine and the weight
savings over steel will be welcome.
The 1/8” hardened steel shaft, the
ball bearings, the shaft clamps (Figure
7), and the screws for the drum’s teeth
and the ones to mount the drive motors
were all sourced from McMaster (Figure
Things were progressing well up to
the point I started modifying the 2118
Outrunners that are the basis for the
weapon motors. It was easy to separate
Figure 8. McMaster screws.
Figure 9. Weapon motor
Figure 11. Bellhousing in mill.