Page:Practical Treatise on Milling and Milling Machines.djvu/150

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An Interesting Use of a Circular Milling Attachment on the No. 3 Vertical Spindle Milling Machine

Surfacing such a casting as this would ordinarily be done by following the outline of the piece of work, using the longitudinal and transverse automatic table feeds. But this necessitates shifting the feeds at each corner of the casting. A better way was found when the casting and fixture were clamped to the table of a circular milling attachment and fed in a circular path beneath the cutter.

The shorter distance the mill has to travel, the time saved in shifting feeds, and the fact that the operator does not have to give his undivided attention to the job, are all important advantages.

The metal is $1⁄2$" thick. By the usual method, it is difficult to secure the flat, oil-tight surface that is easily obtained in the way described above.