Machinery Repairman

In-Line Boring
To set the horizontal boring machine for a line
boring operation, insert a boring bar into the spindle
and pass it through the work. The boring bar is
supported on the foot end by the backrest assembly.
Depending on the size of the bore, you can use either
standard or locally manufactured tooling. The head
Figure 8-11.—Drilling in the horizontal boring mill.
provides the rotary motion for the tools mounted in
the boring bar. Align the work with the axis of the
boring bar and bolt and/or clamp it to the table. In the
cutting operation, the spindle usually moves while the
work is held stationary. However, there may be times
when you need to hold the bar in a fixed position and
move the table lengthwise to complete the operation.
(See fig. 8-12.)
Figure 8-12.—Boring bar driven by the spindle and supported in the backrest block.
8-9