CNC is an abbreviation of Computer Numerically Controlled. It is a new feature widely available for machine tools like lathe, milling, drilling etc. to enhance their working ability and efficiency with the aid of a computer. Till date, the working of some these machines is manually operated which give no chance for operators to rest or concentrate on other tasks. CNC machines are considered as it offered high average precision and accuracy and also time efficiency.
Today we’ll be looking at the definition, parts, element, working principle, types, specification, applications, as well as advantages and disadvantages of CNC machines.
- 1 What is a CNC machine?
- 2 How CNC machines work:
- 3 Parts of CNC Machine:
- 4 Elements of the CNC Machine system:
- 5 Types of CNC Machine:
- 6 Specifications:
- 7 Applications of CNC Machine:
- 8 Advantages and Disadvantages of CNC Machines:
What is a CNC machine?
CNC machine can be defined as machine tools that are automatically controlled by the means of a computer. CNC machine processes a piece of material like metal, plastic, wood, ceramic or composite to meet the spec of a coded programmed instruction without a manual operator.
The working program is written by a person or generated by graphical computer-aided design (CAD) software. As for 3D printers, the part to be printed is sliced before the program will be generated on the computer. The second operation of CNC machines is known as Computer-aided manufacturing (CAM), the topic is similar to CAD but discuss the production areas.
For some component that requires numbers of different tools like drills, mills, saws, etc. modern machines comprise multiple tools into a single cell. However, a number of different machines use an external controller which the component is moved from machine to machine by human or robotic operators. In either case, the steps are applied on parts that require a very close match with the original CAD
How CNC machines work:
The working of a CNC machine is quite interesting due to the fact that it is a computer base. The machine works based on CAD and CAM programs as well as computer control. just as earlier mentioned, the CAD is a drawing software of the item to be produced, which serves as a carbon-copy of the product. That is, the computer automatically produces what the CAD display. It is also used to improve the productivity of the designer, improve communication through documentation, improve quality of design and create a backup file for the next production.
Whereas, CAM (Computer-Aided Manufacturing) features two different code such as G-codes and M-codes on which all programs are written and feed to the machine to perform various operations i.e. the turning and grooving operation on a lathe.
The video below contains the working of lathe CNC machine:
Below are codes used in CNC programming:
The M-codes represent the miscellaneous machine commands which do not command axis motion. The format is the latter ma followed by two to three digits. Below are five functions:
- [M02 End of Program]
- [M03 Start Spindle – Clockwise]
- [M04 Start Spindle – Counter Clockwise]
- [M05 Stop Spindle]
- [M06 Tool Change]
G-codes are used for commanding specific movement of the machine, such as machine moves or milling functions. G-codes differ between lathe and mill application. The format is latter G followed by two to three digits. Below are some functions of G-codes:
- [G00 Rapid Motion Positioning]
- [G01 Linear Interpolation Motion]
- [G02 Circular Interpolation Motion-Clockwise]
- [G03 Circular Interpolation Motion-Counter Clockwise]
Parts of CNC Machine:
Machine tools that feature CNC comprise of the following parts:
- Tailstock quill
- Footswitch or pedal
- Control panel
- Tool turret
Elements of the CNC Machine system:
The following stated below represent the elements of CNC machining system:
- Tape Reader
- Servo system
- CNC machine tool
Types of CNC Machine:
CNC machines are can be classified into the following types:
- CNC laser cutting machine
- 5- axis machine
- CNC Lathe Machine
- CNC Milling Machine
- 3-D Printer
- CNC router Machine
- CNC Plasma Cutting Machine
- Pick and Place Machine
Specification of a CNC machine can be categorized into these following points:
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- Centres height.
- Distance between centres.
- Swing diameter over the bed.
- Swing diameter over the cross slide.
- Transverse movement of the cross slide.
- Hole in the headstock spindle.
- Spindle end-use taper.
- Spindle diameter.
- Spindle end taper.
- Sleeve travel.
- Rapid transverse.
- Programmable feed rate.
Main Spindle specifications:
- Speed range.
- Output power.
Applications of CNC Machine:
These are some applications of CNC Machine:
- The main application of the CNC machine is to work at greater accuracy and automatically control the machine tool.
- This is also used in large fabrication industries.
- This machine is used for automatic removal of metal from the workpiece.
Advantages and Disadvantages of CNC Machines:
The following stated below represent the advantages of CNC machines:
- mistakes in cutting conditions or in dimension can easily be edited Provides better precision and accuracy to the workpiece.
- Fewer workers required which helps to saves the labour cost.
- A high skilled operator not required.
- Complex designs with high accuracy in minimum possible time can be produced on CNC machines.
- It features an online editing program, which means any changes and modified by the part data store in the computer without sending the tape for re-processing.
- The conversion of the unit can easily be done by this machine (SI to British or from British to SI).
- It can diagnostic its own fault easily, there is a special software enables easy to troubleshoot if the CNC system fails to operate and also have the capability to assist in maintaining and repair the system automatically.
- It also helps with safety reasons.
- Low Maintenance required
- Reduce setup-change over time.
- The CNC Machine has Higher Production and capability.
- It can run for 24 hours a day.
- It is Reliable.
Despite the great benefits of CNC machine some limitations still occur. Well, here are some disadvantages of CNC machines:
- The installation cost is high.
- Even do the parts of the CNC machine are high.
- It requires highly skilled professionals to solve issues when a failure occurs.
- Computer knowledge is required.
- Program knowledge is required
That’s it for this article, “Everything you need to know about CNC machines”. I hope you the knowledge is attained, you can freely ask a question via our comment section. Don’t forget to share with other students. Thanks!