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position tiny screws into tiny unadorned holes. Even with
these pleasant design features, one might wonder if the
folks behind a kit as complicated as the Bioloid could make
something suitably accessible for complete novice
Keep in mind that Robotis is also the company behind
the whimsical and accessible OLLO bug kit. We first worked
with the OLLO bug in the April 2009 issue, and the intrepid
arthropods resurfaced in the March 2012 issue. Both times,
the bugs proved to be superbly accessible kits that
showcased super cool mechanisms that were buildable,
even by the greenest novice.
With this sort of family background, we were excited to
dive into the STEM kit. The compact box packs a surprising
amount of robot, and the plethora of parts gave an exciting
preview of what was to come. The Standard kit contains
two motors, or rather AX-12W Dynamixel modules to be
precise. The AX-12W is one of the smaller members of the
Dynamixel family, but it sports the same impressive gear
ratio of 32:1 and a no load speed of 300 rpm. The STEM
kit also includes a nice set of sensors.
A funky T-shaped circuit board is home to numerous IR
transmitter and receiver pairs. It also comes with three
individual IR sensors.
The STEM kit uses the same brain as the Bioloid — a
CM-530 module. All of those electronic bits are wired
together with motor and sensor cables that come in a
variety of sizes. To satisfy its hunger for power, the kit
comes with eight holders for individual AA batteries. We
are used to seeing battery packs with most kits nowadays,
and the AA battery holders seemed like a bit of an odd
throwback. We would soon learn, however, that every
design decision in the STEM kit leads to great teachable
The rest of the box was filled with structural parts. The
basic building blocks of the STEM kit recall those of the
OLLO bugs. The basic panels have a pattern of holes that
come in two sizes: small holes for screws and large holes to
accommodate rivets. Plastic rivets were the fastener of
choice for the OLLO bug, and we were impressed that the
unassuming devices were effective.
The rivet fasteners are comprised of two parts: a core
with an appearance reminiscent of a dull nail and a slotted
casing. The core slides into the casing and when pressed
down completely, it can hold panels together snugly. The
kit even comes with two tools to aid in construction: a
small Philips head screwdriver and a tool designed to aid in
removing the rivets.
A few details about the structural bits stood out to us.
First, the base plates and other panels were labeled with a
grid that identified the dimensions by numbers and letters.
Even though counting to 10 is easy enough, a quick look at
the edge of a panel is a much more convenient way to
confirm that you have the right piece. Also, each bag of
screws and nuts is actually labeled with the part number.
Most kits do this, but we’ve come across some that don’t.
So, we like to give kudos when the kit designers endeavor
to make things as easy as possible.
A PLETHORA OF PARTS.
THE CM-530 BRAIN.
TOOLS OF THE TRADE.
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