Featured This Month:
Features
28 PARTS IS PARTS:
Data Points: Fine-Tune
Your Bot’s Performance
by Pete Smith
30 MANUFACTURING:
Tentacle Calculator
Rehosted by Killerbotics
by Kevin M. Berry
30 Open Melt – Generous
Sharing or a Threat to
Society as We Know It?
by Kevin M. Berry
33 Dual-Differential RPM
Sensing or a Melty Brain/
Translational Drift Robot
by Rob Glidden
34 COMBAT ZONE’S
GREATEST HITS
by Kevin Berry
Events
34 June/July 2010 Upcoming
Events
35 EVENT REPORT:
2010 Central Illinois
Bot Brawl
by Dan Toborowski
28 SERVO 06.2010
PARTS IS PARTS
Data Points:
Fine-Tune Your Bot’s Performance
● by Pete Smith
Knowing exactly how well your bot performs in a particular
configuration would be very
useful ... like, exactly how fast is
the blade turning? What current
is the weapon motor drawing at
start-up and at cruise? How much
does the battery voltage sag at
full power?
Knowing those figures, one
could then try different drive
and/or weapon motors, bigger or
smaller blades, try different
gearing to the weapon, higher
voltage battery packs, or ones
with better current ratings, and
see if overall performance or
efficiency could
be improved.
An easy way
to gather that
data is with a
data logging
device such as
the Eagletree
Micropower
E-Logger V3
(Figure 1) from
www.eagletreesystems.com.
These devices (<$100,
weight 0.7 oz) connect between
the battery and the bot, and
directly record battery voltage
and current over time. Other
sensors can be added to
measure motor speed, blade
speed, battery and motor
temperatures, etc.
I found the most useful
additional sensors were those for
brushless motor RPM and
temperature. The sensors were
easy to fit following the
instructions supplied.
The E-Logger comes with
FIGURE 1
