25 January 2017

Milling machine parts

Milling machine parts

  • Base
The base is made of grey iron casting accurately machined on its top and bottom surface and serves as a foundation member. It gives support and rigidity to the machine and also acts as a reservoir for the cutting fluids.
  • Column 
The column is the main supporting frame mounted vertically on the base. The top of the column is finished to hold an overarm that extends outward at the front of the machine.
  • Knee 
The knee is a rigid casting mounted on the front face of the column. The knee moves vertically along the guideways and this movement enables to adjust the distance between the cutter and the job mounted on the table. The adjustment is obtained manually or automatically by operating the elevating screw provided below the knee. The top face of the knee forms a slideway for the saddle to provide cross travel of the table.
  • Saddle
The saddle rests on the knee and constitutes the intermediate part between the knee and the table. The saddle moves transversely, i.e., crosswise (in or out) on guideways provided on the knee.
  • Table
The table rests on ways on the saddle and travels longitudinally. 
The table rests on guideways in the saddle and provides support to the work. 
The table is made of cast iron, its top surface is accurately machined and carriers T-slots which accommodate the clamping bolt for fixing the work. 
A leadscrew under the table engages a nut on the saddle to move the table horizontally by hand or power.
The worktable and hence the job fitted on it is given motions in three directions:
Vertical (up and down) movement provided by raising or lowering the knee.
Cross (in or out) or transverse motion provided by moving the saddle in relation to the knee.
Longitudinal (back and forth) motion provided by hand wheel fitted on the side of the feed screw.
For universal milling, machine table may also swivel 45° to either side of the centre line and thus fed at an angle to the spindle.
  • Overarm
The Overarm is mounted at the top of the column and is guided in perfect alignment by the machined surfaces. The Overarm is the support for the arbor. The arm is adjustable so that the bearing support may be provided nearer to cutter.
  • Front Brace 
The front brace is an extra support that is fitted between the knee and overarm.
The front brace is slotted to allow adjustment of the height of the knee relative to the overarm.
  • Spindle 
The spindle of the machine is located in the support part of the column and receives power from the motor.


  • Arbor support 
The arbor support is fitted to the Overarm and can be clamped at any location on the Overarm. Its function is to align and support various arbors. The arbor is a machined shaft that holds and drives the cutters.
  • Elevating screw
The upward and downward movement to the knee and the table is given by the elevating screw that is operated by hand or an automatic feed.