Turning Ovals, etc., by Means of a Template
Ovals are generally turned by causing the work to move in and under guidance of an “oval chuck”.
There seems no reason why the same result should not be arrived at by communicating a movement to the rest supporting the cutting tool in the following manner:—Let A, A, be lathe bearers, B, pulley, C, screw of mandrel, D, template fixed thereon, E, friction wheel on the end of bar F, G rest (a board of any convenient width) moving on pivots at H. The friction roller, E, is to be kept in contact with the template by the cord running over the pulley T, stretched by the weight L. The rest will thus oscillate under the guidance of the template, which may be either oval or rose engine pattern, and the cutting tool form the pattern of the template used. There might be other modes of causing the rest to oscillate on the same principle. The lathe would require a slow motion, the same as with an oscillating mandrel.