Base: The base is foundation part of a milling machine. It is made of grey cast iron. It absorbs vibrations and supports column, table arbour, etc.
Column: It is main casing mounted on one side of the base. This is box shaped and fitted with gearing arrangement for different spindle speeds and table feeds (Figure 19.41).
Knee: It is rigid grey cast iron part that supports band and provides adjustment for the height of the table operated by the elevating screw. Knee slides up and down on the vertical dovetail guideways of the column. It carries the table feed mechanism and controls to feed in longitudinal, cross, vertical and rotational, etc., either by hand power or machine power.
Table: Table is the part on which job is mounted either directly by clamp or by a fixture. It rests on saddle and travels longitudinally. The table travel is limited by the adjustable stops in either direction during power feeding. In case of universal milling machine, there is an arrangement of table to swivel horizontally around the centre of its base.
Feed Gear Box: The variation of power feed to all movement is achieved through the feed gear box. The power from the feed gear box is transferred to the knee by a telescopic shaft. The number and amount of feed depend on the gearing arrangements in the feed gear box.
Spindle: The spindle is mounted on the upper part of the column. It receives power from the motor through belts, gears, clutches, etc., and can be rotated at different speeds by the step-cone-pulley drive or gear drive.
Arbour: The arbour is an extension of spindle on which various cutters are mounted. The arbour is set in spindle cone (Morse taper cone) and tightened by draw bolt held in position by a bush nut.
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