Automatic Machine Tool Control Systems: A Brief Account of the Potentialities of Two British Electronic Systems

MUCH thought about the automatic control of machine tools has been confused by an imperfect understanding of what can be done, and of what the advantages of the various systems arc. Why is it desirable to use automatic control? The answer to this question depends on the production quantities involved. Where really large scale production is possible automatic control, combined with automatic transfer equipment, reduces the need for repetitive handling and machine control operations to be done by men, can greatly speed up production, and reduce the need for skilled and unskilled labour. This is not the type of work for which man is best suited, and he may be liable to make mistakes because of fatigue or boredom. In this type of automatic production line the operation can best be controlled mechanically by systems incorporating trips, limit switches, interlocks and the like, specially designed for the sequence of operations concerned. Such mechanical systems have been developed over the years, and many plants, such as those used by large steel works for the production of repetition forgings, show considerable ingenuity in their design. However, such plants are not applicable to a wide range of component designs made in comparatively small numbers, the normal state of affairs in the aircraft industry. Greater flexibility is obtained by the use of electronic control, and the computer which then has to be brought into the system can also carry out some of the more laborious drawing office processes, such as interpolation between ordinates.