Page:Practical Treatise on Milling and Milling Machines.djvu/119

Rh a new piece of work in place. A narrow, stiff hair-bristle brush is good for this purpose when milling cast iron, but one with wire bristles is better for cleaning out steel or wrought iron chips. It is well to clamp a piece lightly, then tamp it down at all bearing points with a hammer; after which it can be solidly fastened.

Aside from these few general instructions on placing and clamping work, little can be said, because the shape of a piece of work alone determines how it may be best fastened. But a study of the methods of clamping shown in the examples of work in this and succeeding chapters will be of great value to the reader.

Fig. 60

Setting Vise. Light work is usually held in a vise, as it is more convenient than any other method of fastening it to the table. To set a vise with plain base so that its jaws are parallel to the spindle, place an arbor in the spindle and then bring the vise jaws up to the arbor. (See Fig. 59). It can be set at right angles with the spindle by a square placed against the arbor and the jaws. The front of the table of the machine can also be used in setting the vise.

Swivel vises can be set by aid of the graduations on their base.

Direction to Move Work Under Cutter. Whenever possible, it is advantageous to feed the work in the opposite direction from that in which the cutter runs. (See A, Fig. 60). Then the cutter cannot draw the work in as it is liable to do when the table moves in the direction indicated at B. Moreover, when the piece moves as shown at A, the