Milling Machine Main Parts and Types with Diagrams

It is a machine that is used to remove metals from the workpiece with the help of a revolving cutter so-called milling cutter. It is used to machine the rough, flat, and irregular surfaces and this is done by feeding the workpiece against a revolving milling cutter.

Main Parts of Milling Machine   

·         In a Milling machine every individual part performs an important task.

·         Some important parts of a Milling machine are as follows:

1. Knee

It is a casting that supports the table and saddle. All gearing mechanism is surrounded inside the knee.

·         It is secure to the column by dovetail ways.

·         The knee is adjusted and supported by a vertical placing screw (elevating screw).

·         The elevating screw is used to adjust the knee up and down by lowering or raising the lever either with the help of a power feed or hand.

2. Column & Base

The column counting base is the main casting that supports all other parts of the milling machine.

·         The column contains an oil tank and a pump that lubricates the spindle.

·         The column rests on the base and the base covers the coolant reservoir and a pump which is used during machining operation that requires coolant.

3. Power Feed Mechanism

It is the knee that covered the power feed mechanism. It is used to control the longitudinal (right and left), crosswise (in and out) and vertical (up and down) feeds.

·         To get the desired rate of feed on the machine, the feed selection lever is located as designated on the feed selection plates.

·         On some universal knee and column milling machines, the feed is obtained by turning the speed selection handle until the wanted rate of feed is designated on the feed dial.

·         Most of the milling machines have a speedy traverse lever which can be engaged when a temporary increase in the speed of the longitudinal, transverse, or vertical feeds is required. For example, this lever would be engaged when the operator is aligning or positioning the work.

4.  Arbor Support

It is a casting with a bearing that supports the outer end of the arbor. It is also helpful in aligning the outer end of the arbor with the spindle.

·         It prevents the springing of the outer end of the arbor during cutting operations.

·         These are generally two types of arbor supports to be used in the milling machine. The first one has a small diameter bearing hole, 1-inch in maximum diameter. And the other one has a large diameter bearing hole, usually up to 23/4 inches.

The arbor supports have an oil reservoir that lubricates the bearing surface. It can be fixed anywhere on the overarm. The arbor supports it,s used only in the horizontal types of milling machine

5. Ram

The hanging arm in the vertical machine is called a ram. One end of the ram straddling on the top of the column and on the other end milling head is attached.

·         The ram can be moved transversally (out and in) on the column by a hand lever.

6. Over Arm / Overhanging Arm

It is a horizontal beam current at the top face of the column. It may be a single casting that slides on the dovetail ways present on the top face of the column.

·         The overarm is used to fasten arbor support. It may contain one or two cylindrical bars which slide through the holes in the column

Types of Milling Machines

1.      Horizontal Milling Machine

2.      Vertical Milling Machine

3.      Knee-Type Milling Machine

4.      Ram-Type Milling Machine

5.      Manufacturing or Bed-Type Milling Machine

6.      Planer-Type Milling Machine

Basically, the milling machines are divided into two types first is a vertical milling machine and the second is a horizontal milling machine. They are further categorized as ram-type, knee-type, manufacturing or planer-type, and bed-type milling machines.

Most of the milling machine categorized above has a self-electric driven motor, power operated, coolant systems table feed, and variable spindle speeds.

1. Horizontal Milling Machine     

In a horizontal milling machine, the axis of revolution of the spindle is horizontal to the table. And due to the axis of the spindle being horizontal, it is called a horizontal milling machine. 

2. Vertical Milling Machine

The milling machine in which the spindle axis is vertical to the table is called a vertical milling machine.     

3. Knee-Type Milling Machine

The milling machine which has a knee-like projection in the middle is called a knee-type milling machine. It is characterized by a vertically adjustable work table resting on a saddle supported by a knee.    

4. Ram-Type Milling Machine

A milling machine that has a ram on the top of the column is called ram type milling machine. Generally, ram is used in vertical milling machines. It can be moved on the column in the transverse direction (i.e. in and out when operated from the knee side).

5. Planer-Type Milling Machine:

The planner milling machine is generally used for facing operations in mass production.

These machines are similar to the bed-type mill machine, except they can be straddled with various cutters and spindle heads the machine.

These cutters in the machines can complete the facing operations simultaneously which is a great function.