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Athena Carrier Boards
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Athena EDU board
Software has built-in
It contains syntax and
code examples for
NUTS & VOLTS
You won’t believe this web site
Circle #96 on the Reader Service Card.
acrylic's paper backing, which is then
rough-cut on a band saw or scroll
saw. Identical components are sandwiched together with thin acrylic double-sided tape, and then stacks are
sanded to a fine polish on a belt
sander. Additional machining operations — like drilling or filing — can be
performed at this time, as well. These
techniques work equally well on thin
frictional and loading forces, or the
range of motions, and you will fail.
Dan paid particular attention to these
necessary details. Manufacturing
accurate, yet simple hip and ankle
joint linkage would have been a real
chore, but many answers can be
found at your local hobby shop.
These linkage parts must provide
smooth, precise motions for a variety
of craft traveling in excess of 60 MPH,
and costing thousands of dollars.
Using them in a small terrestrial
biped may not have been in the
hearts and minds of their manufacturers, but it is perfectly valid to adapt
them to our own purposes.
Please notice the detail in Photos
4-7, showing the degrees of freedom
in the hip and ankle.
Again, simple techniques and
materials blend nicely with intelligent
design to provide robust joints.
Referring to medical texts, other
robotics researchers, and even
Leonardo DaVinci, Dan developed an
overall proportional schematic to follow for the relationships of the joints.
Subtleties such as the fact that a
human finger segment length is 1.25
times longer than the one before were
not overlooked. Literally building from
the ground up, he developed the joint
designs serially, starting at the ankle,
and working up toward the hip.
Following the conventional robotic leg design of three degrees of freedom for the hip, two for the ankle,
and one for the knee, SAMM has as
many degrees of freedom as your
standard research grade university
robot. In Figures 1 and 2, the relative
component lengths are shown to
allow you to model your own walker
on Dan's success.
Joint Task Force
Of critical importance in any
mechanical system are the joints. The
sliding, rotating, moving portions are
a real deal maker/breaker. Ignore the
Again, looking toward the hobby
market, we find every personal roboti-cist's best friend: the R/C servo. Over
the last five years, Hitec has really
straightened up their act, and now
have a vast line of quality servos.
Hitec is probably the choice of the
discriminating roboticist, for selection, quality, price, and performance.
Utilizing Hitec's HS-645MG servos gave a reasonable balance
between cost and function. These
were used throughout the legs to
accommodate the added stresses in
this critical portion, without having to
resort to the rather deluxe and pricey