The mechanism is based on the sliding-link mechanism of an ellipsograph consisting of links 1, 2, 3 and 4. Added to this linkage is cross-shaped slider 5. The mechanism is intended for tracing body and space centrodes of links 2 and 4. The tracing stylus is at centre E of slider 5 . The mechanism is shown set up for tracing space centrode Cs. To trace body centrode Cb, , link 2 is secured to the fixed plane and link 4 is released. Centrodes of various shapes can be obtained by varying the distance between pivots A and B. This is accomplished by adjusting pivot B along slot F of link 2.
$1246$LG,Ge$