Civil Engineering Reference
In-Depth Information
Protecting the table
It is important to keep the top surface of the rotary table clean and free from
dents and machining marks. For this reason, the work should not be clamped
directly onto the rotary table but should be raised above the table's surface
by some sort of packing piece. Something soft such as aluminium or brass
would do to protect the rotary table's surface.
CENTRING
Centring the table
To centre the table below the machine's spindle, you need to put a lever dial
test indicator into a collet or drill chuck that is in the machine's spindle. Move
the rotary table approximately under the centre of the spindle. You can do
this either by sliding the rotary table into position and clamping it down or by
clamping the table down first and then winding the milling machine table's
handles so the rotary table is under the spindle.
Bring the dial test indicator down into the rotary table's centre hole and ro-
tate the spindle carefully. By using the milling machine table's handles you
can now centre the table exactly under the spindle. You must do this by care-
fully rotating the dial test indicator inthe machine'sspindle. Youcannot dothis
by rotating the rotary table's handwheel. If you just rotate the rotary table, the
centre hole will remain in contact with the dial test indicator and you cannot
set it true this way. Many beginners do not realize this and then wonder why
the rotary table is not under the spindle's centre line.
Centring the work
Oncetherotarytableiscentredandthedigitalreadoutorthemachine'shand-
wheels have been set to zero, or the position required, we can set the work
true on the table. A simple way to do this is to put a round bar into the ma-
chine's spindle and line this up with a hole in the workpiece. If you do not have
a bit of bar the correct size to fit into the hole, turn a bit of bar on a taper that
will go into the hole about halfway and use this to line up the work. After a
while you will have several different sizes of taper you can choose from.
