The Efficient Control of Twist Drills: Notes on some of the Difficult Problems in Drilling that Beset the Fitter Available to Purchase

ONE of the noticeable effects of the extensive application of drill jigs is a steady decline in the number of fully qualified hands. Too many operators are jig specialists and quite unable to handle anything else. This is hardly a matter for surprise. After all, the main function of a jig bushing is to control the movements of the drill, and to anyone accustomed only to this kind of work it is an extremely difficult matter to acquire, in a short time, the entirely different technique of jigless drilling. This awkwardness, however, is not incurable. Actually, it is a question of knowing how to prepare for drilling, as much as the drilling itself. It is because the opportunity of learning from others is not always present that the writer of these notes presents, for the first time, a selection of the methods favoured by himself. They will not miraculously transform an incompetent driller into a competent one, but they will help materially in the process.