Circular Machine - The Rose Engine

The Circular machine, known more correctly as the Rose Engine, is the original from which the entire engine turning process is derived. It is a variation of the simple turning lathe, modified by having a rocking and traversing headstock, the rocking or traversing motions being constrained by wavy cams called rosettes, set upon the barrel of the machine; hence the name Rose Engine. Early rose engines had straight line chucks fitted to them for rectilinear work; later the straight line machine was developed as a specialist tool which is more versatile and produces higher quality work.

A small Plant rose engine as produced in Birmingham by G Plant during the second quarter of the twentieth century. We have quite a few examples of this type of machine, which is very useful for small production items as it can rotate much faster than a larger machine without inertia induced vibrations. Although it is a small machine, we regularly use one like this for producing salvers of up to 14 inches in diameter, much used by the hotel industry. Our largest rose engine can handle a salver of around a metre in diameter, circular or oval.

The Plant 7 inch rose engine. We have two very good examples of this model, dated 1928 and 1929, each a unique variant with different rosettes. This image, from a Plant brochure, shows one fitted with an oval chuck.