order the parts,
and have them
appear at your
doorstep in a
matter of days.
Given the newness
of the service, we
had a lot of
Anchor Labs has
every query (most often in a matter of minutes). They even
took our hand drawn part sketchings, and on top of it all
they even had better prices than the local brick and mortar
shops we got quotes from. So, it was “Anchors” aweigh.
At this point, you might be thinking that we’ve spent
well over half our time cutting up wood, and sitting and
staring at Protobot’s denuded frame. You would be right
about that, but that’s because the hardest work is always
done during the design process, and having the physical
mockup (and some old school drafting skills) enabled us to
get that hard work out of the way so that the frenetic fun
of the actual build would unfold without going off the rails.
Our Anchor Labs’ parts arrived in a couple of weeks, and
they were smooth, shiny, and ready to make our skeletal
frame start to look like a robot.
While waiting for our custom parts, we made
numerous orders to McMaster-Carr for the rest of our drive
train parts: 3/4” shafts, sprockets, keyways, bearings,
aluminum tubing for spacers, chain, and so many fasteners.
With all of our parts finally in hand, we cranked up the
music and got to work.
Master of Sprockets
Our first order of business was to get the cannon
mounts mounted, since they would help determine
placement of the motors. (Who needs CAD when you have
a tape measure and dial calipers?) We scribed out the
placement, center-punched the holes, and drilled them out
with a center drill and then the regular bit — just like we
would do with Troublemaker and our FIRST robots. To prep
the bearing blocks, we heated the blocks with a torch to
expand them, then dropped the bearing inside and pressed
it in place with our hydraulic press. The struts with the
cannon mounts went on, then the inner bearing blocks,
and the frame became distinctly more robot like.
It was then time to work on our wheel stacks. The 6”
long shafts were stock parts from McMaster, and they
happened to be the perfect size. Getting them ready
involved lots of cutting with the hacksaw and deburring
with various files, and we spent many hours making sure
the fit was just right. It’s tedious work, but made better by
a good playlist. Everything from Boston and Firefall, to
Lacuna Coil and Metallica carried us through.
Given the speed of the motor and the size of our
wheels, the unreduced speed of the robot would have been
around 30 MPH — way too fast! With a small sprocket on
the motor shaft and larger ones on our driven wheels, we
cut the speed in half to a much more manageable clip. To
ensure the sprockets lined up, we cut spacers out of an
aluminum tube. Measuring the right size for the collars was
a little tricky, since we needed to line up the sprockets in
situ. That’s where telescoping bore gauges came in handy.
FIRST TEST-FIT OF THE CANNON.
EVAN FOR SCALE.
CHASSIS COMING TOGETHER.
58 SERVO 08.2017