What Is a CNC Machine?
The term CNC stands for ‘computer numerical control,’ and the definition of CNC machining is that it is a substandard manufacturing process that typically employs computerized controls and machine tools to remove layers of material from stock grinding — which Known as a blank or workpiece — and produces a custom-designed part. The process is suitable for wides ranges of materials, including metals, plastics, wood, glass, foam, & composites, & the finds applications in a variety of industries, such as larges CNC machining, prototyping for parts machining and telecommunications, & CNC machining Aerospace parts, which require stricter tolerances than other industries.
Note that there is a difference between the CNC machining definition and the CNC machine definition — one is the process, and the other is the machine. A CNC machine is a programmable machine capable of performing CNC machining operations autonomously.
While substandard processes remove layers of material from the workpiece to create custom shapes & designs, additive processes assemble layers of materials to produce the desired form, and initial processes deform and displace the stock material to the desired shape.
Automated natures of CNC machinings enable the production of high precision and high accuracy, simple parts, and cost-effectiveness when one-time and moderate-volume production runs. However, while CNC machining exhibits some advantages over other manufacturing processes, the degree of complexity and complexity for part design and the cost-effectiveness of producing complex parts are limited.
The cutting operation performed by CNC is called CNC machining. CNC machining programs are first designed or prepared and then fed to a CNC machine. According to the program, CNC controls the speed and speed of machine tools.
CNC Block Diagram:
Parts of CNC Machine:
The main parts of CNC machine are, and The following represent the various CNC machine parts:-
#1. Input Device
These are the device that is used to input part programs in a CNC machine. There are three commonly used input devices, & these are punch tape readers, magnetic tape readers, and computers via RS-232-C communication.
#2. Machine Control Unit (MCU)
This is the heart of the CNC machine. It performs all the controls functions of the CNC machine, the various tasks performed by the MCU are It reads the coded instructions givens in it. It decodes the coded instruction. This axis applies interpolation (linear, spherical, and helical) to generate motion commands.
It feeds the axis speed order to the amplifier circuit to drive the spindle mechanism. It receives feedback signals of position and speed for each drive axis. It implements auxiliary control functions such as coolant or spindle on / off and tool change.
#3. Machine Tools
A CNC machine tool always has a slidings table & a spindle to control position and speed. The machine tables are controlled in the X and Y-axis direction, & the spindle is controlled in the Z-axis direction.
#4. Driving System
The driving system of the CNC machine consists of an amplifier circuit, drive motors, and ball lead screws. The MCU feeds the signals (i.e., position and speed) of each axis into the amplifier circuit.
The control signals are then amplified (amplified) to activate the drive motors. And actuated drive motors rotate the ball lead screw to position the machine table.
#5. Feedback System
The system consists of transducers that act as sensors. It is also called a measurement system. It consists of position and motion transducers that continuously monitor the position and speed of the cutting tool located at any given moment.
The MCU receives signals from these transducers, and it uses the difference between reference signals and response signals to generate control signals to correct position and motion errors.
#6. Display Unit
A monitor is used to display programs, commands, and other useful data of the CNC machine.
On CNC machines, these parts bear all the weight of the machine; this means that all other components are mounted on it. The bed component is made of hardened materials such as cast iron because the tool turret passes over them in CNC lathe machines.
The headstock is one of the mains components of the CNC lathe machines due to the fact that the workpieces are fixed to it. The CNC lathe features motors to help drive the main axle.
This lathe provides additional grip to the workpiece when performing operations such as noodling, threading, turning, part of a CNC machine. Support is provided on the end surfaces of the workpiece.
#10. Tailstock Quill
The tailstock quill helps to centralize the workpieces between the headstock and the tailstock.
#11. Footswitch or Pedal
The pedal is used to open & close the chuck while trying to hold the component, such as the tailstock quill is moved to the forward and reversed positions.
The chuck is mounted on the main axle, which gives the tool space to fix.
#13. Control Panel
Control panels are also one of the important parts of CNC machines that are used to set or feed programs for the operation to be performed on the workpieces. It is also called the brains of the CNC machine.
Also, Read: Simple Indexing in Milling Machine
Advantages of CNC Machine:
- It can generate employment with the highest accuracy and precision than any other manual machine.
- It can be run for 24 hours.
- The parts produced by it have the same accuracy. There is no variation in manufactured parts.
- It does not require a highly-skilled operator to operate. A semi-skilled operator can also work more accurately and accurately.
- Operators can easily make changes and corrections and reduce delay times.
- It has the ability to design complex designs with high accuracy in the shortest possible time.
- Modern design software allows the designers to emulate the creators of his idea. And it eliminates the need to creates prototypes or models and saves time and money.
- Fewer workers are required to operate CNC and save labor costs.
Disadvantages of CNC Machine:
- Despite having so many advantages, it also has some disadvantages. And these are:
- The cost of these machines is very high as compared to manually operated machines.
- CNC machine parts are expensive.
- Maintenance costs are higher for CNC machines.
- The machine requires expensive equipment to operate.
- The cost of CNC machines is much higher than a manually operated machine.
- CNC machine parts are expensive.
- Maintenances costs are significantly higher in the case of CNC.
- This does not eliminate the need for expensive equipment.
Application of CNC Machine:
- CNC machines are used in almost every manufacturings industry. With increasing demand in the manufacturing industry, the use of CNC has also increased. The machine tools that come with CNC are lathes, mills, shapers, welding, etc.
- Almost every manufacturing industry uses CNC machines. With the competitive environment and increasing demands, the demand for CNC usage has increased substantially. The machine tools that come with CNC are Lathe, Mills, Shaper, Welding, etc.
- The industries using CNC machines are the automotive industry, metal removal industry, metal forming industry, electrical discharge machining industry, wood industry, etc.