Featured This Month:
Features
26 BUILD REPORT:
Reversing the Trend
by Pete Smith
27 MANUFACTURING:
DIY CNC for CAD/CAM
by J. Miles
30 PARTS IS PARTS:
Kitbots Rolls Out B- 16
Gearmotor Mounts
by Kevin Berry
31 RioBotz Combot Tutorial
Summarized: LaunchBots
Summarized by Kevin Berry
34 Combat Zone’s Greatest Hits
by Kevin Berry
Events
35 Feb/Mar Results and
May/Jun Upcoming Events
35 EVENT REPORT:
Motorama 2010
by Chris Olin
26 SERVO 05.2010
BUILD REPORT:
Reversing the Trend
● by Pete Smith
Irecently completed our first drum bot — Weta, God of Ugly
Things (Figure 1). And while it is
a pretty conventional design, it
does have one feature rarely seen
in bots of this type: The drum is
reversible, so it can spin in either
direction.
Drum bots work best when
the drum is spinning so that the
teeth will come up and catch an
opponent and throw them up
into the air. If the bot gets flipped
over, the teeth then try to push
the opponent down instead. This
has proven to be pretty
ineffective (Figure 2).
Weta was
designed to be
completely
invertible and it
can operate
equally well either
way it ends up
since it is able to
quickly and
smoothly reverse
the direction of
rotation of the
brushless motor that powers the
drum. Reversible Electronic Speed
Controllers (ESC) have been used
for some time in RC cars, but
have been cost-prohibitive. The
FIGURE 1
FIGURE 2
