on a thin part where it has little
effect, but it would have been a
problem on a 1" thick part like the
Team Whyachi's waterjet
machine can angle the jet to account
for this, and so can produce vertical
sides to even thick parts.
Other orders went in to
McMaster-Carr and Online Metals
etc., for the various screws and clips
required, the titanium shaft, and a
length of 3" x 1" 7075 aluminum.
The aluminum was machined
into the rear C-shaped panel and a
vast pile of metal chips. The last step
was to machine the big chamfers
that keep it clear of the ground if the
nose of the bot is lifted up.
I completed this using an
angle vise on my milling machine
I machined a couple of clearance
areas a little too deep and managed
to break a 1/8" end mill off in one of
the holes. The over-machining didn't
affect how the parts fit, and I
managed to get the remains of the
end mill out and still leave about 2/3
of the thickness for threading. So, it
worked out okay.
Both problems were simply the
result of not taking enough time and
hurrying to finish. They ended up
costing me more time than if I had
just taken things a little slower.
The watercut parts arrived
(Figure 5), and I marked them up for
the secondary machining they would
require. I carefully marked which
holes and which sides needed to be
countersunk. (It wouldn't be the first
time I've countersunk all the holes in
a panel only to discover I did it on
the wrong side.)
The locations and depths were
marked up on the UHMW parts, and
then these were more accurately
marked out and machined on a mill
I made up the bot’s wiring loom
(Figure 7) using an XT60 connector
to match the battery (Figure 8)
through a Finger Tech power switch,
to a pair of female Deans type
connectors for the speed controllers.
I have fitted the matching male
Deans to the ESCs (Electronic Speed
Controllers) and plan to use a new
connector from Hobby King to
connect the motors to the ESC.
The power-on LED will be
30 SERVO 03.2014
FIGURE 7. Wiring loom.
FIGURE 8. The 1,300 mAh battery.
FIGURE 6. Milling UHMW sides.