Elliptical Trammel

The Elliptical Trammel (also known as the Elliptic Trammel, or the Trammel of Archimedes) is a simple mechanism which can trace an exact elliptical path. Figure 1 shows the geometry of this mechanism, which consists of two prismatic (or sliding) joints and two revolute (or rotational) joints. These joints guide the movement of a central rigid body. 

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