Manufacturing Systems
TITLE: Theory of CNC machines
OBJECTIVES:
- To understand the programming requirments and setup process of a CNC milling machine;
- To produce a part on a CNC milling machine
APPARATUS:
- Denford Router 2600 Pro 3 axis CNC milling machine.
THEORY
Router 2600 Pro 3 axis CNC router is an lab computer numerically controlled milling machine. The system is a full 3 axes machine that is commonly used in educational institution. It has an integral manual data input (MDI) panel and system function keys for interaction with user. An internet interface is also available for communication with an external host computer for the uploading and downloading of programs. It is available with 5 Station Automatic Tool Changer.
The input format conforms to the international G and M codes format for CNC machine controllers.
PROCEDURE:
1. The instruction manual for the CNC milling machine should be consulted whenever there are problems. Safety precautions should be observed at all times.
2. Write a CNC part program for the 2-dimensional diagram in Fig.1. Show to the tutor to check any errors in the program.
3. Start-up the machine according to the procedure for machine start-up in the instruction manual. Execute the machine warm-up procedure.
4. Enter the program into the machine. Specify a program number of the format O00xy where x is your year in the course and y is your group number. Only one program number is allowed for each group. Note that any program which is not conforming to the program number format may be deleted for extra memory space.
5. Set up the tool diameter offset for the tool you select. Set-up the zero point of your work. Do an air cut to check any errors in the machine motions. Ask the tutor to check the machine while it is doing air cut.
6. Mount a workpiece on the milling machine and cut it. Hand it to the tutor when it is perfect
BRIEF DESCRIPTION OF THE PROGRAM
I am going to use language called RS-274D but it is commonly known as t “G-code” or “G&M Code” because many of the words of this language begin with the letters G or M.
While many of the words used by different CNC machines are the same, there are differences between makes and models. This is due in part to machines having different configurations and options. For example, a machine with a chip conveyor will have words to turn the conveyor on and off, while a machine without a conveyor does not. So, while RS-274D is a standard, it is not rigid or enforced. Always refer to the machine documentation for the exact words and syntax for your CNC machine.
The G-code language was developed when machine controls had very little memory. It was therefore designed to be as compact as possible. While at first this language may seem arcane, the modern machine tool language is the safest and most efficient way yet devised to control machine tool motion. G&M codes, along with coordinates and other parameters, comprise what is called a CNC program.
DISCUSSION
CNC Machine Operators require skills in operating a CNC machine but are not machinists. Through industry task analysis as well as strong involvement with development of large global manufacturer, Amatrol’s CNC Machine Operator Program brings a highly focused, streamlined set of skills to CNC Machine Operator training. Many training programs for CNC Machine Operators use training really designed for machinists, which incorporates a lot of theory not relevant to the role of CNC Machine Operator. For example, a CNC machine operator needs to know how to run a CNC program – not how to design one.
Amatrol’s CNC Machine Operator Program focuses exclusively on the modern CNC machine operator, including such tasks as maintaining machines and recording SPC (Statistical Process Control) data. It covers all the skills operators need, from operating the CNC machine to set-up of tooling and fixtures to quality inspection.
CONCLUSION
CNC Machining is a process used in the manufacturing sector that involves the use of computers to control machine tools. Tools that can be controlled in this manner include lathes, mills, routers and grinders. The CNC in CNC Machining stands for Computer Numerical Control.At the end of the experiment I have gained a lot of programming aspect of CNC Machine and the language used to make CNC machine programe.
REFERENCES
“CNCCookbook Blog Posts Relating to GCode Programming.” CNCCookbook Blog Posts Relating to GCode Programming 06 APRIL 2015: 10-12.
Shoujin Sun, PhD. Manufacturing Systems. MANU 2095, 1999.
