Large General Purpose Frame for Studying Force Vectors

Many illustrations and problems on the vector nature of forces have weights and forces in a vertical plane. One of the common devices for studying the vector nature of forces is a horizontal “force table,”¹ in which forces are produced by weights hanging vertically and transmitted to cords in a horizontal plane. Because some students have difficulty relating the geometry of the textbook illustrations with weights in a vertical plane to the horizontal geometry of a force table, we developed a vertical force frame, shown in Figs. 1 and 2, that allows a vertical arrangement of weights and cords that mimics exactly the textbook illustrations, and is on a scale that makes it easy for the students to “feel” the magnitudes of forces. This frame is easy to build, inexpensive, and provides a working area of almost 5 ft × 5 ft (1.8 m × 1.8 m) and a number of alternative ways of working with forces. This frame can also be easily expanded to an area of 10 ft × 5 ft (3.6 m × 1.8 m) for large complex configurations. The frame is easy to assemble or disassemble using only a VSR drill and deck screws, and stores compactly. Students can gain engineering skills by assembling the frame guided by schematic drawings.