Lathe Operations: Facing

Facing Operations Facing is the process of removing metal from the end of a workpiece to produce a flat surface. Most often, the workpiece is cylindrical, but using a 4-jaw chuck you can face rectangular or odd-shaped work to form cubes and other non-cylindrical shapes.

When a lathe cutting tool removes metal it applies considerable tangential (i.e. lateral or sideways) force to the workpiece. To safely perform a facing operation the end of the workpiece must be positioned close to the jaws of the chuck. The workpiece should not extend more than 2-3 times its diameter from the chuck jaws unless a steady rest is used to support the free end. Cutting Speeds

If you read many books on machining you will find a lot of information about the correct cutting speed for the movement of the cutting tool in relation to the workpiece. You must consider the rotational speed of the workpiece and the movement of the tool relative to the workpiece. Basically, the softer the metal the faster the cutting. D…

How to make a curve?

Turning requires manual dexterity, visual judgement and the co-ordination of hand and eye. In this respect it is similar to games like tennis. Such activities require the development of what psychologists term 'motor skills'. The learning and development of these skills require relatively long periods of practice.

It has been said that it can take seven years, working full-time, for a turner with aptitude to reach the peak of his abilities and become fully skilled. But again this should not deter the beginner. What does 'fully skilled' mean? It means that the turner can perform all the operations with speed and accuracy. At the top level, for a professional needing to earn a living, speed is an important ingredient in skill.

This can be illustrated by the so called 'learning curve' which may be familiar to the reader. The general shape of the learning curve is illustrated in below Diagram.

learning curve

It can be seen from this that typically, with continual practice, the individual goes through a period of steady improvement. Then after some time the rate of improvement begins to level off and eventually there comes a time when very little further improvement takes place. In reality it is found that some individuals have more innate ability than others. Generally, too, where motor skills are involved, it is best to start young. Usually, those who have an early start eventually reach higher levels of skill than older people. But older people should not despair: on their way through life they may well have acquired skills which will be of assistance to their endeavour in the woodturning field.

Different learning curves

Because of the differences between individuals, their innate ability, their age, or their previous useful experience, each turner will have his own distinctive learning curve. Some possible, contrasting, curves are shown in above Diagram. Individual C is a very slow learner but he improves little by little. Individual B is a quick learner and reaches his full capacity earlier than individuals A or C. But, although A is a slowish learner, he eventually becomes more skilled than B.


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