FL 111 represents a simple bar structure. In the single plane system the bars are only subjected to compression and tension. Loads are applied only to the nodes.
The unit comprises three bars that are joined together using disks such that the joints are free to move. A longi-tudinally adjustable bar permits the bar structure to be constructed with different angles. The bars engage in the disks by snap-locks. Two of the node disks also form the supports (fixed and movable) and are clamped to the sturdy aluminium section base frame. The external load is applied to the upper nodal point by means of weights.
The bar forces occurring are measured by the deformation of leaf spring elements in the middle of the bar.