MILLING MACHINE OPERATIONS - OD1644 - LESSON 1/TASK 1
lathe center, bearing against the arbor nut (figure 4 on the previous page)
or by a bearing surface of the arbor fitting inside a bushing of the arbor
where an intermediate arbor support is positioned.
The most common means of fastening the arbor in the milling machine
spindle is by use of a draw-in bolt (figure 4). The bolt threads into the
taper shank of the arbor to draw the taper into the spindle and hold it in
place. Arbors secured in this manner are removed by backing out the draw-in
bolt and tapping the end of the bolt to loosen the taper.
Screw Arbor (figure 5 on the following page). Screw arbors are used
to hold small cutters that have threaded holes. These arbors have a taper
next to the threaded portion to provide alignment and support for tools that
require a nut to hold them against a tapered surface. A right-hand threaded
arbor must be used for right-hand cutters; a left-hand threaded arbor is
used to mount left-hand cutters.
Slitting Saw Milling Cutter Arbor (figure 5).
The slitting saw
milling cutter arbor is a short arbor having two flanges between which the
milling cutter is secured by tightening a clamping nut. This arbor is used
slitting, and sawing operations.
End Milling Cutter Arbor. The end milling cutter arbor has a bore in
the end in which the straight shank end milling cutters fit.
Shell End Milling Cutter Arbor (figure 5). Shell end milling arbors
are used to hold and drive shell end milling cutters. The shell end milling
cutter is fitted over the short boss on the arbor shaft and is held against
the face of the arbor by a bolt, or a retaining screw. The two lugs on the
arbor fit slots in the cutter to prevent the cutter from rotating on the
arbor during the machining operation. A special wrench is used to tighten
and loosen a retaining screw/bolt in the end of the arbor.