# What is a milling machine?

A milling machine is a machine tool used to rough, drill, cut and/or detail, whether it be metal, wood or any solid material. These operations are accomplished by rotating and moving a cutting tool called a “milling cutter” through a set of cranks, one for the vertical axis (z-axis) and two others for the horizontal axis (x, y-axis).

## Parts of a milling machine

This machine tool is a bit complicated in terms of its construction since it is made up of too many parts. This time we will only talk about the most essential and basic parts of the milling machine.

### Worktable

Usually, a clamp is placed on the work table to hold the piece.

### Cranks

• Vertical: This crank moves in the vertical axis or Z axis.
• Longitudinal crank: This mechanism moves the worktable in the X-axis.
• Cross handle: The worktable moves on the Y-axis.
• Head crank: This crank as its name implies is used to move the head on the vertical axis.

The head is the device where the cutting tool is placed.

### Motor

It is practically the most important part of the milling machine since it generates the rotary movement of the cutting tool.

## Types of milling machines

We can classify milling machines in different ways, either by the number of axes, by the orientation of the tool or by its special characteristics.

### By the number of axes

The number of axes determines the possibilities of movement of the milling machine.

• 3 axes: This type refers to the main X, Y, Z axes.
• 4 axes: It incorporates the axes of the previous type and includes an accessory inside the work table that gives the possibility of turning the part to be machined.
• 5-axis: This type has all the characteristics of the four-axis and also incorporates the possibility of tilting the piece.

### By the orientation of the tool

• Verticals: The head is placed on the vertical axis. We can find a fixed bench and a turret.
• Horizontal: As the name implies, the tool is placed on the horizontal axis.
• Universal: Combines the two previous types of milling machines, since the tool can be placed both horizontally and vertically.

### Due to its special characteristics

• Manuals: These are the simplest, they are 3-axis and the movements for machining are done manually.
• Mobile bridge: In this type, the worktable remains immobile and the tool is the one that does the job.
• Copier: As its name implies, this type specializes in copying the designs of the pieces.
• Circular: This milling machine has a large rotary circular table.
• CNC: These milling machines (computer numerical control) are used through a program in which all the machining instructions are entered and the machine executes them automatically.