Page 273 - Robots Androids and Animatrons : 12 Incredible Projects You Can Build

12.6 Gearbox placement in sphere
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The first component is a small length of tubing / 8" outside diameter
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1
(OD), / 2" inside diameter (ID), and about / 8" long. This tubing is
glued to the center of the half sphere, using the marks as a guide.
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Inside the tubing, glue a / "-diameter half round about / " long.
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This piece may be glued inside the tubing before the tubing itself
is glued into the sphere.
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Next, cut a small length of / 2"-diameter solid rod. On one end of
the rod, remove a / 8" half section. This is accomplished using a
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hacksaw or coping saw. First make a cut directly down the center
of the rod about / 8" deep. Then make a horizontal cut to remove
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the half section. Check to make sure this shaft fits easily into the
3 / 8" tube and half round assembly inside the half sphere. If not, file
the cut end until it does. At the opposite end of this rod, drill a hole
down the center that will fit the shaft from the gearbox.

Note: On the prototype robot, I made the second shaft a drive con-
nection also. Only when the robot was finished did I realize that
this was unnecessary. A single drive connection works just as well
as a double.
The second half sphere is easier to make. Glue a small length of
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/ 8"-OD, / 2"-ID tubing to the center of the half sphere, using the
Team LRN
Chapter twelve