Milling is a metal-removal process that involves feeding the workpiece against a spinning cutter with one or more cutting blades. Milling machines can machine flat or curved surfaces of various workpieces with good finish and accuracy. A milling machine can also be used for drilling, slotting, creating a circular profile, and gear cutting with the right attachments.
What is a Milling Machine?
The milling machine is one of the most versatile traditional machine tools, capable of cutting a wide range of metals. A milling machine can perform various complex operations such as indexing, gang milling, straddle milling, and so on.
Parts used in Milling Machines
The different parts of the milling machine are:
Column and base – The column and base of a milling machine support the other components.
Knee – A vertical positioning screw, often known as an elevating screw, supports and adjusts the knee.
Saddle and Swivel Table – The saddle is on the knee and supports the table, while the Swivel table is attached to the saddle, which swivels (revolves) horizontally in both directions.
Power Feed Mechanism – The power feed mechanism is located in the knee. The longitudinal (left and right), transverse (in and out), and vertical (up and down) feeds are all controlled by it.
Table – On the top of the saddle, there is a rectangular casting called a table.
Spindle – The spindle of a milling machine is the shaft that holds and drives the cutting tools.
Over Arm / Overhanging Arm – This is a horizontal beam that runs the column’s top face length. It could be a single casting that slides along the dovetail channels on the column’s top face.
Arbor Support – An arbor support is a casting with a bearing that supports the arbor’s outer edge. It also aids in aligning the arbor’s outer end with the spindle.
Ram – The vertical machine’s overhanging arm is known as the ram.
Different types of milling machine
● Vertical Milling Machines
The vertical mill rotates by staying on the same axis and features a vertically positioned spindle axis. The spindle can also be extended to accomplish drilling and cutting operations. There are two types of vertical mills: turret mill and bed mill.
The turret mill uses a table that moves perpendicularly and parallel to the spindle axis to cut the material. The spindle, on the other hand, remains immobile. Two cutting methods are possible by shifting the knee and lowering or lifting the quill.
On the other hand, the bed mill has a table that travels perpendicular to the spindle’s axis and a spindle that moves parallel to its axis.
● Horizontal Milling Machines
The horizontal mill is a cutter that is identical to the vertical mill, except it is mounted on a horizontal arbor. Many horizontal mills use rotary tables for milling at different angles. These are referred to as universal tables. Aside from that, all of the tools used in a vertical mill can be utilized in a horizontal mill as well.
Milling machine process
The various types of milling operations goes through the following cutting processes or phases:
● Milling Cutters
In the milling process, many different cutting tools are employed. Milling Machines can hold multiple cutters at a time. End mills are milling cutters with specific cutting surfaces on their end surfaces that allow them to be drilled into the workpiece. For peripheral milling, these also have expanded cutting surfaces on both sides. At the terminal corners of the milling cutters are little cutters. The cutters are made of high-strength, long-lasting materials that cause minimal friction.
● Surface Finish
The milling machine cuts materials passing through its cutting area at regular intervals. Regular ridges can be found on the side cutters. The distance between the ridges is determined by the feed rate, cutter diameter, and the number of cutting surfaces. There can be significant height differences between the surfaces.
● Gang Milling
In a horizontal milling system, this means that more than two milling cutters are used. It’s possible that all of the cutters do the same operation or that each cutter performs a different job.
Milling Machine Applications
These are some of the areas where milling machines are used for:
● A milling machine can be used to create a variety of gears.
● In most cases, it’s utilized to make slots or grooves in workpieces.
● It has the ability to process both flat and uneven surfaces.
● It is used in the manufacturing industry to create complex shapes.
Conclusion
Though milling machines come in various shapes and sizes, their primary function stays the same. Nonetheless, getting the correct machine for the job is critical. We hope this information has given you a better knowledge of milling machines and how they differ.
Also Read: What is a CNC Machine and How Does it Work?