higher end
requirement still
under discussion
would be for the
bot to grasp an
unconscious
person and pull
them out of an
extremely dangerous situation, to a
spot where rescue workers could
intervene.
Being a near-farm boy myself,
(we lived in town, but it had 800
people and only one hardware
store), I thought about what a rural
farm shop might have available to
build something like this. Out of
that came some general design
requirements:
End of Bot Dimensions.
Frame Dimensions.
hardware, home
improvement, or
farm supply store.
Rest easily ordered
on-line.
5) Power by common motorcycle,
ATV, jet ski, snowmobile sealed
lead acid battery; 120 VAC battery
charger on board.
• Four Victor 883 ESCs
• Two Hawker/generic SLA batteries
• Steel frame
• Cheap, simple, and robust
1) Must be able to be built in a
medium sized farm or school shop,
or a welding shop by generally
handy people.
2) Must be able to function in an
explosive atmosphere. This means
the electrical devices must be fully
enclosed.
3) Any functions done in the field
(on/off switch, changing payloads,
carry bars) can be done in full
turnout gear with breathing mask
(gloves, full face mask, coat, boots,
helmet). Radio can be operated with
bare hands.
4) Most parts available at a chain
6) Service and major component
replacement in firehouse using only
common hand tools.
7) One failure tolerant for critical
functions (Multiple motors each
side? Parallel ESCs?).
8) Indicators provided (LEDs) to
assist in troubleshooting and
operational verification. Critical
indicators must be visible through
binoculars from several angles.
After some preliminary back
and forth brainstorming, Chewy
from Team Tiki popped in with a
rock solid basic parts list:
• Four NPC T- 64 gearmotors
Within 15 minutes of seeing
this list, I was on The Robot
MarketPlace ( www.robotmarket
place.com) — my favorite vapor bot
“pick list” site. I recognized that
buying new might not be possible,
given the limited resources of a rural
fire department, but it seemed like
a good starting point. Out of that
exercise came the following design
“concept.” These are ugly as
original sin and twice as smelly, but
remember we’re being honest here.
We’ve all done it, even if we don’t
show them in public. So here, using
PAD software (Powerpoint Aided
Design) is what I came up with.
(I added two batteries, a master
switch, hubs and wheels, and radio
system to Chewy’s basic list). I then
PAD
Design.
CAD
Design.
SERVO 05.2008 21