Double Eccentric Work

A Double Eccentric pattern is cut with two centres of rotation. One in which the work is rotated between cuts to index them and the other the actual cutting motion, which can be wavy or plain circular as in these two examples. The term is used only where both axes of rotation are in the same plane, unlike the trumpet shaped base recessed up it's length, or a sunray on a sphere.

A pair of "Cache Button" or button covers for this shirts that don't have the extra button hole for cuff links. In this design, the arc cuts are made by rotating the work about a centre near to the edge, and then rotating it about it's own centre a small amount to move on to each new cut. Thus the term double eccentric or two centres.

This example is similar in principle, except that the centre of the arcs is further away, off the workpiece.

There are huge numbers of variations on the theme of double eccentric work. The examples above only use plain circular arcs. Elliptical arc segments can be used, and in all cases the arcs can wave if a rosette is used.