RECAP – Class 4
• Advantages and Disadvantages of NC
• Configurations of CNCs and DNCs
• DNC configurations – satellite and Switching
• Design criteria – M/c str – static, dynamic, thermal loads.
Classification of NC Machine Tools
, Some design criteria for CNC machine tool design
Machine Response Operating and cost
Component Considerations
Considerations considerations
Type of command signal Undamped natural frequency Reliability
Input configuration Power requirement Maintainability
Maximum feed rate Friction characteristics Cost of operation
Static accuracy Inertia Capital investment
Dynamic accuracy Stiffness Installation Requirements
Magnitude of load Amount of backlash
Range of travel Speed range
Weight of moving Machine structure (Static load,
members Dynamic load and Thermal Load)
Power source
Email:
, MACHINE STRUCTURE
• The machine structure is the load carrying and supporting member of the
machine tool.
• All the motors, drive mechanisms and other functional assemblies of machine
tools are aligned to each other and rigidly fixed to the machine structure.
• The machine structure is subjected to static and dynamic forces and it is,
therefore, essential that the structure does not deform or vibrate beyond the
permissible limits under the action of these forces.
Email:
• Advantages and Disadvantages of NC
• Configurations of CNCs and DNCs
• DNC configurations – satellite and Switching
• Design criteria – M/c str – static, dynamic, thermal loads.
Classification of NC Machine Tools
, Some design criteria for CNC machine tool design
Machine Response Operating and cost
Component Considerations
Considerations considerations
Type of command signal Undamped natural frequency Reliability
Input configuration Power requirement Maintainability
Maximum feed rate Friction characteristics Cost of operation
Static accuracy Inertia Capital investment
Dynamic accuracy Stiffness Installation Requirements
Magnitude of load Amount of backlash
Range of travel Speed range
Weight of moving Machine structure (Static load,
members Dynamic load and Thermal Load)
Power source
Email:
, MACHINE STRUCTURE
• The machine structure is the load carrying and supporting member of the
machine tool.
• All the motors, drive mechanisms and other functional assemblies of machine
tools are aligned to each other and rigidly fixed to the machine structure.
• The machine structure is subjected to static and dynamic forces and it is,
therefore, essential that the structure does not deform or vibrate beyond the
permissible limits under the action of these forces.
Email:
