CNC quiz 1 latest update with certified answers

CNC quiz 1 latest update with certified answers numerical control a means of auto control of machine tool actions by a set of coded instructions and commands computer NC microprocessors are built into control to perform functions direct NC control of one or more CNC machines by a host computer distributive NC control of a group of CNC machines by a network of computers two types of control signals motion control signals, misc control signals electric pulses and control # of pulses =axis position pulse frequency=axis velocity functions by misc control signals(ON/OFF) spindle rotation+direction, control of coolant supply, selection of cutting tools, auto clamping/unclamping BLU basic length unit, min increment size of NC one BLU increment=0.01mm in old NC =0.0001 mm in modern CNC two reasons inhibited use of direct NC industry could not afford the costly main frames and intro to CNC advantage of CNC reduce cost, improve quality, facilitate production planning and control limitation of CNC high initial investment, high maintenance requirement, not cost effective for low production runs 6 major elements of CNC part program, program input device, machine control unit, drive system, machine tool, feedback system 3 commonly used program input devices punch tape reader, magnetic tape reader, NC card for network computers. functions implemented by MCU read/decode coded instructions, implement interpolations, feed axis motion commands to amplifier, feedback signals, auxiliary controls 3 constituted elements of CNC drive amplifier circuits,