Important questions with answers-Question Bank for CNC machine and its components

1. Compare CNC and NC.

NC

• Tape reader is less reliable
• Metric convention is not possible
• Control is hard wired

CNC

• Computer memory is more reliable
• Automatic convention is possible
• Computer controls the NC system

2. What is CMM?

CMM stands for Coordinate Measuring Machines. Which is used to measure the dimensions of a work piece.

3. What are the types of turning center?

Horizontal machines, vertical machines.

4. What are the advantages of CNC machine?

• High accuracy
• Long tool life
• Reduced inspection
• Requires no special tool setting

5. What is ATC? 

ATC is called as automatic tool changer. It is a important part in a machining center. ATC pickups a tool from the magazine and keeps it ready for processing with a tool in the spindle.

6. How the ATC classified?

Single tool, Multi tool head, Parallel axis and intersecting axis tool

7. What are the requirements of slide ways?

• Low coefficient of friction
• Low wear rate
• Sufficient damping
• High stiffness.

8. Describe about tool magazine.

Tool magazine is used to store all cutting tools used by CNC machine tools delivers the tool to be used to the position of tool changing under the control of CNC machine.

9. What is encoder?

• Encoder is a device which is used to convert the linear or rotational information into electrical output signal.
• A NC system in which all positional dimensions are measured with respect to a common datum point is called a digital absolute system. 
• The transducers give a direct reading of position with reference to the common datum.
• All position commands are given as absolute distances from the datum point (zero point).

10. Sketch any show the parts of a recirculated ball screw and nut.

11. What are feedback devices?

Encoder, Optical encoder, Absolute encoder, Incremental encoder, Resolver.

12. What are the uses of feedback devices in CNC?

They provide a signal back to the drive or motion controller to monitor an operation or process and verify that proper operation occurs.

13. Explain tool probing.

Tool setting and broken tool detection system is called as tool probing.

14. What is transducer?

Transducer is a device which is used to convert one form of energy into another form of energy.