Development and Performance Investigation of a Laboratory Screw Jack

Abstract

This study is aimed at developing a screw jack that can be used for experimental demonstration to science students for better understanding of efficiency of a lifting device, mechanical advantage and relationship of effort to load during lifting. The design put into consideration of material selection, cost and easy operational use. The screw jack was put to test under various loads of; 50N, 100N, 150N, 200N and 250N and effort to lift each load, distance travelled by load and effort at different interval was recorded. Graphical relationships from the reading were established for effort vs load and efficiency vs load to show that effort increases with increase in load and efficiency of the screw jack was around >50%. The result also show efficiency and velocity ratio are not constant due to presence of friction in the system.