Dead loading was applied to the bearings. The bearings were held in the plastic support structure. The bearing was mounted on the lower support, the washer glued to the upper support. The support structure was held by bushings at the top and bottom (only bottom bushing shown). A variable speed dc motor below the bottom plate drove the lower support holding the bearing. The upper support holding the washer was able to move up and down in the top bushing but was restrained so that it could not rotate. Dead loading weights were placed on the upper support.