An Analysis of Gravity-Fed Hacksawing for Force and Cutting Rate Prediction

Abstract

This paper briefly reviews the cutting action and blade performance tests of common hacksawing operations. The acceptance tests for hand hacksaw blade performance in the British Standard and the omission of these tests in the current Australian Standard are also discussed. The analysis presented is particularly relevant to hand hacksaw blade testing conditions. In contrast to previous research on power hacksaw blades, the proposed analysis considers the machine-blade-work-piece as a total system for predicting the forces during the cutting strokes and the cutting rate. The computer-aided model indentifies and incorporates numerous salient machine, blade and workpiece variables. For prediction purposes the model requires both static and dynamic tests of the gravity-fed hacksaw machine as well as limited sawing tests for establishing the tooth force per unit area of cut functions. Good correlation between experimental and predicted forces and cutting rates has been achieved when testing the effects of blade pitch, tooth cutting edge radius, workpiece proportions and added masses on the machine swing-arm assembly. This investigation has highlighted the complexity of this common machining operation and the importance of the machine geometric, kinematic and dynamic features when standardising blade performance tests.