Within this project, it is evaluated how a mechanism works, the parts needed to build it, and how the mechanism can apply to the real world.
Mechanism and Application
My partner and I chose mechanism 144 from “507 Mechanical Movements,” a system of crossed levers, termed “Lazy Tongs.” This mechanism works as levers are crossed over one another and pinned at the overlapping center and points. With a rod on either side of the mechanism, these are pinned to the final levers, allowing for a horizontal movement, compressing, and expanding the mechanism. Previously, this mechanism has been used in ship pumps about three-quarters of a century ago and has been applied to a machine operated in France to raise sunken vessels. In modern times, these cross-lever operations are seen to be used in children’s toys.
Prototype
This prototype was constructed using cardboard scraps and gold pins, allowing the levers to be adjoined. Tape was used as well to hold down the base point of the mechanism, as well as two parts to the left pulling bar.
In the prototype process, the cross-levers were made from four parts, each connecting at the endpoints and centers by the gold pins. It was found that, aside from the end levers that connect to the pull bars, these intersecting pieces can each be one piece made at the same length.
AutoCAD Design
Final Product
The laser cut, final product is made of 3mm cardboard, gold pins, and hot glue used to hold the base down. In comparison to the prototypes, this cardboard cut is much sturdier, and the cross levers were redesigned to be more efficient.