A service company needed to test linear gear actuators for wear. The procedure calls for applying a certain load in compression and extension, and measuring the amount of free play. The test is to be performed near each limit and at the center of the stroke.
B. Dash Fabrication designed and built this test fixture. It uses a length of roller chain to anchor the lever at any spot along the length of the test bed. The slot and roller chain prevent the lever from being tilted side to side, which would screw the worm in or out of the gearbox. A loop on the top of the lever supplies an attachment point for a spring scale, making it easy to accurately calculate the amount of force being applied.