each wheel assembly.
In a differential steering system, the closer the wheels are
together the easier it is to turn.
Make a line across the center of the base that is
perpendicular to the three lines. The easiest way to do this
is to use a piece of paper lined up against the center line
with one corner at the center point on the base.
Place a mark on the center of the wheel assembly as
shown in Figure 21. Then, place the assembly on the base
with the center mark lined up with the new perpendicular
Use three wood screws to attach
the assembly to the base. Place them
at the positions shown in Figure 22.
Do the same with the other wheel
sub-assembly on the opposite side
of the base. Use screws that are
not long enough to protrude through
the opposite side. (I used 1” screws.)
I recommend a pilot hole and
slight counter-sink to prevent the
wood on the wheel sub-assembly
That completes the Megabot
base. Just flip the base over and it
should look like the one shown in
Figure 23. As you can see, there is
quite a bit of room for our power
system and controllers. You may have
noticed that I staggered the wheels
when I built the wheel sub-assembly.
This was done for a couple of
reasons. This allowed me to use less
space and pull the wheels in tighter.
Next month, we will look into our power system and
get those wheels moving. I’m going to be looking at using
the Ryobi Li-Ion 18V battery, as well as a Li-Ion external
laptop battery for our power supply. I will also show you
how to use a PC to get those actuators turning.
Be sure to check out the Kronos Robotics website for
updates to this project at: www.kronosrobotics.com/
Projects/ megabot.shtml. SV
Announcing the Gears Heavy Metal Robot Kit
Designed for Students and Professionals
Heavy Metal is engineered for rigors of daily use in classrooms,
summer camps, workshops, labs . . . even combat robots!
Assembles quickly using fasteners of same size/pitch and
threaded inserts. 10" wheel base, heavy gauge aluminum,
4-wheel drive, 3" rubber wheels, 3/8" axles, flanged
bronze bearings, #25 pitch steel chain and sprockets.
All drive components are keyed and broached.
Competition all-metal gearhead motors, gearbox
rated at 500 oz-in of continuous torque. Heavy Metal
accepts off-the-shelf engineering parts, plus
components and control systems from GEARS IDS,
FIRST and VEX Robotics kits. Heavy Metal 1 Kit includes chassis, motors, drive system, and wheels for $499.00. Lb for Lb
Contact Mark Newby the World's
firstname.lastname@example.org Toughest Robot
s WWW GEARSEDS COM Chassis
*VEX Robotics is a mark of Innovation First, Inc. and FIRS T refers to © US FIRS T (Foundation for the Inspiration and Recognition of Science and Technology)
SERVO 12.2008 53
Supports 200 lbs of