Vertical Force Board (1892) Static forces, torque and rotational equilibrium can be visually exported with this unit that measures 30 inches tall. A circular plate 8-3/4" in diameter revolves on a low friction pin. This plate contains 4 sets of holes with 8 holes in each set. Each set of holes are spaced a different distance from the center. Rotational forces are studied by attaching pins with hanging weights into the various holes and by measuring forces with a spring scale. Qty :