Page 102 - Build a Remote Controlled Robot

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ARMS AND SUBSYSTEMS
robot’s final assembly to protect it from damage. The head
lights when a button (that should come with the auto dome
light kit) mounted on the robot is pushed. Questor’s head
serves two functions: One, as an attention getter, being that
the light is quite bright and, two, to illuminate the objects
being carried on his serving tray, The serving tray will be
mounted at the same time as Questor’s head, during final
assembly. The following sections will detail the construction
and installation of the robot’s arms, drink dispenser, and head.

ARMS

Questor’s arms are very simple to make and install; however,
care should be taken when fabricating them because errors in
the parts may affect the way the arms are mounted and how
level the serving tray sits on the arms. After viewing pictures
of Questor earlier in this book, the way the arms look and
their position should be rather obvious.
The arms are made from 2-inch-diameter PVC piping used
for plumbing (or robot arms). You will need two 8-inch and two
21-inch lengths of PVC. When you buy the PVC, also purchase
two 90-degree turn elbows and four end-caps. Figure 5-2 shows
what these parts look like.
When you cut the PVC piping, be sure to make your cuts as
straight as possible; I suggest you use a miter box to ensure
straight cuts. Cut the lengths of PVC according to Fig. 5-3 and
assemble them, as well as the elbows and end-caps, together
according to the figure. Be sure that the elbows and end-caps
fit snugly on the tubing because you will not be gluing or fas-
tening the parts together.
Once assembled, check to see that the arms are the same
height and length. Do this by standing them next to each other.
If the arms are not correct, all that may be needed is some tap-
ping or pulling of the end-caps so that they fit more snugly or
closer to the PVC pipe, or stick out farther from it. If the devi-
ation is large, you should disassemble the arm and recut a new
section of PVC piping. The piping is usually sold in eight-foot