04-08-2012, 04:07 PM
ANSWER OF ASSIGNMENTS OF CNC TECHNOLOGY
ANSWER OF ASSIGNMENTS of CNC.docx (Size: 14.97 KB / Downloads: 56)
1. What do you mean by numerical control? What are the areas where numerical control can be used?
ANSWER:
Numerical Control (NC) refers to the method of controlling the manufacturing operation by means of directly inserted coded numerical instructions into the machine tool.
It is important to realize that NC is not a machining method, rather, it is a concept of machine control. Although the most popular applications of NC are in machining, NC can be applied to many other operations, including welding, sheet metalworking, riveting, etc.
2. State the advantages of CNC machines over NC machines.
• Conventional NC machines that are not connected to a computer do not have the memory capabilities to run a canned cycle.
• Every move of the cutting tools would have to be listed coordinate by coordinate.
• NC machines also lack the power of a computer’s memory to calculate arcs and curves instantaneously.
• CNC machines have the added feature of graphic simulation. This feature allows the programmer to watch a visual display of how the CNC machine will machine the part according to the program that was just created.
• Any errors in the program will be displayed so that a programmer can debug a program without wasting material or tool bits.
3. What is drive? How is machine tool drives classified?
DRIVE:
Drive are used to control speed(motion) of the machine tools to gain as closely as possible position issued by CNC system.
MACHINE TOOLS DRIVE CLASSIFICATION:
Depending On their characteristic machine tools drive system can be classified as:
Spindle drives (Constant Power)
Feed Drives (Constant Torque)
4. What are the main components of a feed drive? Explain.
Feed Servomotor
An electronic controller