Square deployable frames for space applications. Part 2: realization

In a sister paper, the authors have proved mathematically that the three-dimensional 4R overconstrained Bennett linkage has an alternative form allowing it to be folded up completely. In this paper, the ways of building such structures are shown. For design purposes, a set of design parameters is introduced that could be used for rapid prototyping because they are closely linked with the final expanded configuration. The relationships between the design and geometrical parameters, commonly used to describe the Bennett linkages by kinematicians, have been derived. Moreover, the concept of a single compact folding Bennett linkage has been extended to a grid in which the Bennett linkages are nested within each other. The new assembly retains all the common features of the single linkage. A series of physical models were made, which successfully demonstrate the concept.