A practical and simple tool for accurate milling-machine work-is shown in Figs. 149 and 150.

Fig. 149 - The micrometer attachment used for centering work under an end mill.

Fig. 150 - Centering the work under a face mill.

A common method of setting the work central with the cutter is to place a square on the plate of the machine, with the blade in contact with the work, and caliper between the upper end of the blade and the cutter, first on one side and then on the other. The cutter of course is central when the caliper reads the same on both sides. The graduations on the machine are also used.

After working along these lines for some time, the writer made this micrometer attachment. The stock of the gage is shown as placed against the cutter, and the micrometer barrel is adjusted to make contact on the work.

The work is adjusted until the micrometer reads alike on both sides.

This tool is also handy on lathes, planers, shapers, and for a depth gage.