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The links went through a few adaptations for the mechanism. The first design for the links is seen below.
Designed The links were designed to reduce out-of-plane movement with a large surface area. At the bearing joints, the links would slide sling along each other, and the extra material increases the sturdiness.
Unfortunately, once wired to the motor, the links were too heavy for the motor to move in full rotation. So , so the team had to adapt to a lighter alternative, re-designing the shape of the links to have a bone-like structure.
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This bone structure heavily decreased weight, the T joint decreased from a weight of 64 g to 16 g allowing the motor to rotate the system. The team also lasered the same parts in 1/8in 8" wood and ¼ 1/4" acrylic in case they were needed for further weight loss or structure.
In order to maintain the mechanism aligned out-ofalignment in-plane, spacers were added between each joint. Each joint hole was sized for a bearing press fit. These bearings were flanged and facing each other so any axial forces would further push them into the links. In addition, press-fit spacers were printed for any links that needed additional support.
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Since the mechanism’s rotation goes under below the baseground link, a slot had to be created to allow for the movement as seen in the figure below.
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The motor mount was adapted and printed with inspiration from the Pololu motor mount. The original mount did not fully enclose the motor, it provided bolding bolting holes but once tested it did not keep the motor from vibration once when run at full speed. So a new design was printed that kept the mount holes and added a hood over the motor to restrict vibrations.
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