First, the unique system that creates our large sinking shed: The shaft height is adjusted by a more precise lam connection resulting in improvement in the forming of the progressive shed.

The David has a single set of lams that connect to the treadles and shaft movement is only in one direction, downward.  The shed of the David III has similarities with a counter-march shed: The warp threads are pulled both upwards and downwards, just as with a countermarch loom, so that an optimal shed is created.