Sherline 5000 Mill General Manual

FIGURE 7-Indicating in the center of a hole.
A vise can be mounted or a part can be clamped down exactly parallel with the machine
slides by holding the test indicator stationary and moving the slide with which you wish
to align. When "indicating in" a vise, always take the reading on the fixed jaw. To start
with, use approximately .005" indicator deflection from neutral. Remember that
excessive pressure can cause inaccurate readings. Also, try to keep the indicator finger at
a reasonable angle to the indicated part or surface. When the part is properly aligned there
will not be any deflection on the indicator. If you wish to locate the spindle over an
existing hole, place the indicator in the spindle and read the inside surface. Move the "X"
and "Y" axes until there is no deflection when the spindle is rotated. At this point, the
spindle is in perfect alignment with the hole's center.
When aligning the spindle to used bearing holes, remember that the hole may be worn
out-of-round, and it may be impossible to attain zero indicator deflection reading. Boring
out a worn bearing hole to a larger diameter and sleeving it with a simple bushing made
on a lathe is a fairly common machining operation. With the new bushing pressed in, the
bearing will be like new.