Cnc milling machines
When it comes to manufacturing, there is no better tool than a CNC milling machine. These machines are capable of performing multiple operations such as turning, milling, drilling and threading. These machines find a wide range of applications in engineering sectors such as automotive, aerospace and electrical engineering.
CNC milling machines can be used to perform various machining operations. Numerically controlled (NC) milling machines are used to produce a variety of products through different types of machining operations, such as slot and key cutting, drilling, reaming, tapping and milling.
Applications of CNC milling machines
Numerically controlled milling machines find a wide range of applications in mechanical engineering, such as automotive, aerospace and electrical engineering. CNC milling machines are equipped with a number of different tools that allow various machining operations to be performed. Among the types of machining that can be performed by CNC milling machines are turning, milling and drilling. The most common type of CNC milling machine is the horizontal or vertical machining centre, which has multiple axes and allows the movement of the cutting tool along each axis to be controlled simultaneously.
CNC milling machines can be used for any type of work. Some popular examples are: * Turning: Turning allows an object being machined to be rotated while keeping its original shape intact (although it may be slightly modified). * Milling: Milling consists of using mechanical force against an object to remove material from it in order to create the desired shape or profile * Drilling: Drilling is mainly used to create holes in materials such as metal or plastic; however, there are other uses for this technique (e.g. drilling concrete slabs).
Types of CNC milling machines
The types of CNC milling machines include vertical machining centres and horizontal machining centres. The latter are also known as ‘C’ or ‘C-axis’ mills, because they have a spindle axis that slides in a horizontal direction, unlike vertical milling machines, which have an axis that slides up and down (hence the name ‘VMC’).
Vertical machining centres offer more working space, as their table can tilt from 0° to 90° with respect to the spindle axis. Horizontal models are limited to 0-45° because there is no room to tilt the axes on the table without sacrificing rigidity or stability when cutting long metal parts.
There are no differences between the two machines, except that the spindle of the vertical machining centre slides in a vertical direction, while that of the horizontal machining centre slides in a horizontal direction.
The spindle is the rotational axis of a machine tool. It is driven by a motor, which can be rotating or stationary. The spindle can also slide in both directions along its axis (horizontal and vertical).
The most common type of 3-axis CNC milling machine contains a vertically oriented spindle axis with an X-axis parallel to the workpiece table (Y-axis) and a Z-axis perpendicular to it.
The X, Y and Z axes are perpendicular to each other. In this configuration, X is horizontal, Y is vertical and Z runs in the direction of travel or in the direction of the length of the workpiece. The CNC lathe has a spindle axis that slides in the vertical direction while the #X# and #Y# axes are horizontal.
Stages of a machining operation in CNC milling machines
The following sections describe the operation of a typical CNC vertical machining centre:
- The machine controller (or programmable controller) receives the part program from the CNC machine operator.
- The feed rate and spindle speed are set according to the workpiece programme.
- The cutter is inserted into its holder and lowered into position on the workpiece by means of a suction cup or vacuum system.
- Each movement of the tool is controlled by an encoder that measures the distance moved by each axis of motion, providing feedback to the CNC machine controller.
- The workpiece is machined by moving the tool through multiple axes of motion at a predetermined feed rate and spindle speed.
- The completed part is removed from the machine and inspected for quality control before being packed for shipment.
Conclusion
CNC milling machines have existed for over 30 years, but their production has only become widespread in the last decade. CNC milling machines are used to produce customised products with a high degree of precision and accuracy. In fact, they can produce parts with tolerances down to 1/10,000 of an inch!
Because of this extreme precision, CNC milling machines are used in many industries. Today, companies use them to create tiny medical devices such as pacemakers or artificial joints; cars and aeroplanes; weapons systems; household appliances such as refrigerators and washing machines; industrial machinery such as assembly lines; oil rigs and other drilling equipment… There’s no denying it!
In the coming years, the adoption of CNC milling machines is expected to increase due to their ability to deliver customised products. Demand for customised products is increasing globally and this is expected to drive market growth. The growing need for high-precision machine parts has been a major driver of this market in all regions.
The global CNC milling machines market size was estimated at USD 5.20 billion in 2018 and is expected to reach USD 7.52 billion by 2025 with a CAGR of 5% during 2019-2025, according to a new study published by Grand View Research, Inc.