Fig. 913.
An excellent example of angle plate chucking is shown in [Fig. 912]—the actual dimension of the piece, measuring, say, 24 inches in length. It is required to have the cylindrical stems a, b turned parallel to each other, of equal diameters, equidistant from the central hole c, and true with the hub d. A large piece of work of this kind would be marked off with lines defined by centre-punch dots, as shown. The ends of a, b, d would require dotted circles to set them by. Now, in all work of this kind it is advisable to turn that surface first that will afford the greatest length of finished surface, to serve as a guide for the subsequent chucking, which in this case is the hub d, and the face on that side as denoted by the dotted line which has to be cut to that line. The method of chucking would, for this purpose, be as in [Fig. 913].
Fig. 914.
Fig. 915.
The second chucking would be as in [Fig. 914] to bore the hole at c, while, at the same time, the surface from f to g may be turned. Either inside calipers or a surface gauge may be employed to set e e parallel to the chuck plate surface. It is supposed that the location c is defined by a dotted circle, by which the work may be set for concentricity, as should be the case. At the next chucking it will simply be necessary to move the work on the angle plate to the position shown in [Fig. 915], setting the circle on the end of a to run true, and the surface e parallel to the chuck surface as before. The third chucking is made by simply moving the work on the angle plate again, and setting as in the last instance.