Civil Engineering Reference
In-Depth Information
Fig. 5.8 The digital edge finder usually works by creating an electrical circuit through
the work, the machine and the spindle. For this reason it is not usually used on non-
electrical conducting components.
TRAMMING THE MILL
Tramming the milling machine refers to setting the machine's head square to
the machine's table. This is most often done with a dial test indicator in the
machine's chuck. The dial test indicator is set to a reasonable diameter of
swing, say, about 4-6in (100-150mm) with the stylus clocking up the top of
the table. To avoid the test indicator bouncing up and down over the T-slots,
a parallel should be placed on the table and the test indicator should be set to
the top of the parallel.
When the dial test indicator is swung at equal 90 degree positions, the
amount the head is out of square can be determined and the head adjusted
until the dial test indicator reading is zero at all four positions. This assumes
the head can be rotated both ways. If it cannot be rotated both ways and the
head is out in the direction the head cannot be rotated, then you will have
to square the head up using shims or some other method until the head is
square. Once this is done, the head should remain square in the direction that
