Simple Screw Jack.
Simple Screw Jack Features Low cost, effective teaching Self-contained Bench mounted Introduction to simple machines Determination of velocity ratio mechanical advantage and efficiency Overhauling Three year warranty Range of Experiments Experimental determination of velocity ratio and comparison with calculated value Determination of variation with load of: effort friction efficiency Limiting efficiency of the machine Description This simple screw jack is a 220 mm diameter turntable fitted with a 30 mm x 6 mm pitch screw is supported in a heavy cast iron base. The apparatus is stood on a firm bench and a cord and weight hanger are wound round the rim of the turntable and hung over the pulley. The pulley runs on ball bearings to reduce friction to a minimum. This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results