Design and Fabrication of an Automated Scissors Car Jack to Lift and Lower a Car with Minimal Human Effort

Abstract

Tyre punctures is almost inevitable in vehicles and changing a flat tyre is not a pleasant experience when it is done manually. With the increasing levels of technology, the effort required in achieving the desired output can be effectively and economically decreased by the implementation of better designs. Hence, the objective of this paper is to design and fabricate an automated scissors car jack to lift and lower a car with minimal human effort using appropriate standard methods including decision matrix. In this research an automated scissors jack was designed and fabricated to lift and lower a car. The power screw of the scissors jack has a torque of 28562N-mm, the top arms have a moment of inertia of 48334 mm4 and 77863.5 mm4, the bottom arms have a moment of inertia of 74250 mm4 and 89842.5 mm4, with bending stress of the top plate given as 5.75 N/mm2. A 12V DC motor was selected to drive the power screw. The fabricated automated scissors jack with a power screw torque of 28562N-mm was tested for performance and the results obtained indicate that it was able to raise and lower a load of 452.92kg in an average lift time of 160 seconds and this performance was satisfactory.