computer numerical control machines

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Presentation Transcript

Computer Numerical Control Machines:

Computer Numerical Control Machines Overview Construction Features Position Systems Motion Systems Switching Systems Feedback Devices CNC Programming References

Overview of CNC Machines:

Overview of CNC Mach i nes

Slide 3:

An NC machine tool is functionally the same as a conventional machine tool. The technological capabilities of NC machine tools in terms of machining are no different from those of conventional ones. The difference is in the way in which the various machine functions and slide movements are controlled. Numerically Controlled Machine Tools

Slide 4:

Turning the Spindle on and off Setting Cutting Speeds Setting Feed Rate Turning Coolant on and off Moving tool with respect to workpiece are performed by Machine Control Unit (MCU) in NC machine tools. Functions and Motions

History:

H i story US Air Force commissioned MIT to develop the first "numerically controlled" machine in 1949. It was demonstrated in 1952. At 1970-1972 , first Computer Numeric Control machines were developed. Today, computer numerical control (CNC) machines are found almost everywhere, from small job shops in rural communities to companies in large urban areas.

Definition:

Def i n i t i on In CNC ( Computer Numerical Control ), the instructions are stored as a program in a micro-computer attached to the machine. The computer will also handle much of the control logic of the machine, making it more adaptable than earlier hard-wired controllers.

Sample CNC Machines:

Sample CNC Mach i nes

CNC Turning:

CNC Turn i ng

CNC Milling:

CNC M i ll i ng

CNC mill with 4-axis driver box:

CNC mill with 4-axis driver box Systems are also available without a computer. The 8760 4-axis driver box plugs into the parallel port of a customer-supplied computer

Slide 13:

Complete CNC Shop Package Includes lathe, mill, computer and all accessories shown in inset photo

Industries most affected by CNC:

Industr i es most affected by CNC Aerospace Machinery Electrical Fabrication Automotive Instrumentation Mold making

Sample Products of CNC Manufacturing:

Sample Products of CNC Manufactur i ng

Engine Block:

Engine Block

Different Products:

Different Products

Electronic Industry:

Electron i c Industry

CNC Mold Making:

CNC Mold Mak i ng

Rapid Prototyping Products:

Rap i d Prototyp i ng Products

CNC Applications :

CNC Appl i cat i ons Machining 2.5D / 3D Turning ~ Lathes, Turning Centre Milling ~ Machining Centres Forming 2D Plasma and Laser Cutting Blanking, nibbling and punching 3D Rapid Prototyping

Slide 23:

Cutting a helical gear with the 4th axis

Advantages of CNC:

Advantages of CNC Productivity Machine utilization is increased because more time is spent cutting and less time is taken by positioning. Reduced setup time increases utilization too.

Advantages of CNC:

Advantages of CNC Quality Parts are more accurate. Parts are more repeatable. Less waste due to scrap.

Advantages of CNC:

Advantages of CNC Reduced inventory Reduced setup time permits smaller economic batch quantities. Lower lead time allows lower stock levels. Lower stock levels reduce interest charges and working capital requirements.

Advantages of CNC:

Advantages of CNC Machining Complex shapes Slide movements under computer control. Computer controller can calculate steps.

Advantages of CNC:

Advantages of CNC Management Control CNC leads to CAD Process planning Production planning

Slide 29:

CNC Advantages vis-à-vis NC Increased Program storage capability at the machine Program editing at the machine Control systems upgrades possible Option-resident CAM system at machine tool Tool path verification

Drawbacks of CNC:

Drawbacks of CNC High capital cost Machine tools cost $30,000 - $1,500,000 Retraining and recruitment of staff New support facilities High maintenance requirements Not cost-effective for low-level production on simple parts As geometric complexity or volume increases CNC becomes more economical Maintenance personnel must have both mechanical and electronics expertise

Types of CNC Machines:

Types of CNC Machines Based on Motion Type Point-to-Point or Continuous path Based on Control Loops Open loop or Closed loop Based on Power Supply Electric or Hydraulic or Pneumatic Based on Positioning System Incremental or Absolute

Constructional Features of CNC Machines:

Constructional Features of CNC Mach i nes

CNC System Elements:

CNC System Elements Part program Program input device Machine control unit Drive system Machine tool Feedback system

NC System Elements:

NC System Elements

Part Program:

Part Program A part program is a series of coded instructions required to produce a part. It controls the movement of the machine tool and the on/off control of auxiliary functions such as spindle rotation and coolant. The coded instructions are composed of letters, numbers and symbols and are arranged in a format of functional blocks as in the following example N10 G01 X5.0 Y2.5 F15.0 |       |       |         |        | |       |       |         |       Feed rate (15 mm/min) |       |       |        Y-coordinate (2.5 mm) |       |      X-coordinate (5.0 mm) |      Linear interpolation mode Sequence number

Program Input Device:

Program Input Dev i ce The program input device is the mechanism for part programs to be entered into the CNC control. Th e most commonly used program input devices are keyboards , punched tape reader, diskette drivers, throgh RS 232 serial ports and networks .

Input Media:

Input Media Input Media for the NC code into the Controller are used to electronically or mechanically store the NC programs An NC program is read from the input medium when it is loaded into the machine Old NC machinery could only read programs from punched tape or DNC CNC machines may process multiple means of program input Punched Tape - The oldest medium for program storage Made from paper or Mylar plastic (stronger than paper) The NC program code is entered into the tape by tape puncher in a form of a series of holes representing the NC codes A tape reader by electrical, optical or mechanical means senses the holes and transfers the coded information into the machine computer The NC code is entered into CAM or Word Processor program and punched into tape

Input Media:

Input Media Magnetic Tape Early experiments were not successful due to machine shop environment High quality tapes of today can be used with reasonable care in handling The most commonly used format is ¼ - inch computer cassette tape Standards for tape format and coding have been developed by the Electronics Industries Association (EIA) Floppy Diskette Popularized by the use of PCs in NC programming The NC program is transferred into the CNC control by means of a portable diskette drive attached to the communication port of the CNC machine The most commonly used port is RS232 (serial communication port) Floppy diskettes are cheaper than other program storage options

Tape Formats:

Tape Formats General Today punched tape is not often used for NC program storage Formats used in NC programming are still referred as Tape Formats Computer files containing the NC programs are referred as “tape files”, “punch files” or “tape image files” Old machinery is still used in machine shops RS-274 Format Follows Electronics Industries Association (EIA) standard Program information is contained in program lines called “Blocks” “Blocks” are punched into the tape in one or two tape code standards RS-274 is a “variable block coding” format The information contained in a block may be arranged in any order

Machine Control Unit:

Mach i ne Control Un i t The machine control unit (MCU) is the heart of a CNC system. It is used to perform the following functions: Read coded instructions Decode coded instructions Implement interpolations (linear, circular, and helical) to generate axis motion commands Feed axis motion commands to the amplifier circuits for driving the axis mechanisms Receive the feedback signals of position and speed for each drive axis Implement auxiliary control functions such as coolant or spindle on/off, and tool change

Position System:

Position System To program the NC machine, it is necessary to establish a standard axis The relative positions of the tool with respect to the work can be derived from this standard axis The most significant is axes feed drive which controls the position of the slides which in turn ensures the accuracy of work

Slide 43:

Normally the two axes X and Y are defined in the plane of the table The Z axis is perpendicular to this plane and the movement in the Z direction is controlled by the vertical motion of the spindles Position System

Drive System:

Each axis is equipped with a drive unit such as a dc servomotor, stepping motor or hydraulic actuator The motor drive unit is connected to the table by means of a lead screw Rotation of motor causes the lead screw to turn which results in linear movement of the table The pitch of the lead screw determines the distance traveled by the table on each revolution of the motor Drive System

Stepping Motors:

Stepp i ng Motors

Sherline stepper motor mount FEATURES: ∙ Totally enclosed coupler ∙ Dual ball bearings ∙ Preload nut removes end play ∙ Dampened coupler reduces stress on motor ∙ Solid metal construction ∙ Black anodized finish:

Sherline stepper motor mount FEATURES: ∙ Totally enclosed coupler ∙ Dual ball bearings ∙ Preload nut removes end play ∙ Dampened coupler reduces stress on motor ∙ Solid metal construction ∙ Black anodized finish

Recirculating Ball Screws:

Rec i rculat i ng Ball Screws Transform rotational motion of the motor into translational motion of the nut attached to the machine table.

Profiles of ball screws:

Profiles of ball screws

Preloading:

Preloading

Position Control Systems:

Position Control Systems

Control System:

Control System Open loop system Closed Loop system with indirect measurement Closed loop system using direct measurement.

Open-loop System:

Open-loop System An open loop system by definition do not use any form of feed back control. Open loop system generally uses a stepping motor. The stepping motor is a motor that is driven and controlled by an electrical pulse train generated by the machine control unit.

Open-loop System:

Each pulse drives the stepping motor by a fraction of one revolution, called the step angle Allowable step angle  = 360/N where N = Number of step angles The angle of rotation of motor - P  where P = no. of pulse received by the motor This method of control is relatively cheap to construct Errors that are present will obviously accumulate Open-loop System

Closed-loop System with indirect measurement:

Closed-loop System with indirect measurement Has 2 extra element compared to open loop system Measuring system and Comparator The measuring system is attached to ball screw assembly This measuring unit monitor the angular displacement Thru the feed back this signed is compared by the comparator

Closed-loop System with indirect measurement:

To assure that the table has been properly located w.r.t. tool If any difference is noticed between command and feed back signals, the comparator corrects the positioning signal Suffer from torque effects Due to minute twisting of ball screw as heavy cuts are taken Cannot be monitored. Lead to small error in dimensional accuracy of the part. Closed-loop System with indirect measurement

Closed-loop System with direct measurement:

Linear measuring scales are mounted along the length of each slideway Because the scale runs the length of axis travel results in higher positional accuracy Eliminates torque effects, backlash and pitch errors Linear scales are very costly Closed-loop System with direct measurement

Feedback System:

Feedback System The slides are moved by feed drive servomotors through ball screw and nut drive The slide position measurement Resolver Encoder Linear feed back transducer like optical scale mounted on the motor’s shaft Every positioning movement is monitored and checked This ensures the accuracy and repeatability of positioning

CNC Programming:

CNC Programm i ng

Slide 62:

Engineering design of a part Develop manufacturing plan for the part Program numerical control instructions to allow the part to be manufactured according to the plan Process the program to develop cutter location data set Post Process for a specific machine tool The basic NC Process From Bedworth et al. 1991

Part Programming:

APT (Automatically Programmed Tool) is a software compiler for simplifying numerical control Programming. Developed by MIT in 1959 APT is the most widely used processor Part Programming

Slide 64:

APT Characteristics Three-dimensional unbounded surfaces and points are defined to represent the part to be made Surfaces are defined in a X-Y-Z coordinate system In Programming, the tool does all the moving; the part is stationary. Linear interpolation is used for curved tool paths

Slide 65:

APT Statement Types Identification Geometry Motion Postprocessor (feed, speed, coolant, … etc.) Auxiliary (tool, tolerance, part, … etc.)

Slide 66:

APT NC Words (Codes) N Code - Sequence Number G Code - Control Functions F Code - Feed Rate S Code - Spindle Speed T Code - Tool Selection M Code - Miscellaneous functions X, Y, Z Code - Coordinate position

CNC Programming:

CNC Programm i ng Offline programming linked to CAD programs. Conversational programming by the operator. MDI ~ Manual Data Input. Manual Control using jog buttons or `electronic handwheel'. Word-Address Coding using standard G-codes and M-codes.

During secondary motion, either the tool moves relative to the workpiece or the workpiece moves relative to the tool. :

During secondary motion, either the tool moves relative to the workpiece or the workpiece moves relative to the tool. Basics of NC Part Programming In NC programming, it is always assumed that the tool moves relative to the workpiece no matter what the real situation is. The position of the tool is described by using a Cartesian coordinate system. If (0,0,0) position can be described by the operator, then it is called floating zero.

To define the motion of the tool from one point to another.:

To define the motion of the tool from one point to another. Absolute positioning. In this mode, the desired target position of the tool for a particular move is given relative to the origin point of the program. Incremental positioning. In this mode, the next target position for the tool is given relative to the current tool position. Basics of NC Part Programming

Structure of an NC Part Program:

Structure of an NC Part Program Commands are input into the controller in units called blocks or statements. Block Format: Fixed sequential format Tab sequential format Word address format

Example:

Example Assume that a drilling operation is to be programmed as The tool is positioned at (24,12,0) by a rapid movement. The tool is then advanced -10 mm in the z-direction at a feed rate of 500 mm/min, with the flood coolant on. The tool is then retracted back (10+1) mm at a rapid feed rate, and the coolant is turned off. 1. Fixed sequential format 0050 00 +002400 +001200 +0000000 0000 00 0060 01 +002400 +001200 -0010000 0500 08 0070 00 +002400 +001200 +0000000 0000 09 2. Tab sequential format 0050 TAB 00 TAB +0025400 TAB +0012500 TAB +0000000 TAB TAB 0060 TAB 01 TAB TAB TAB -0010000 TAB 0500 TAB 08 0070 TAB 00 TAB TAB TAB -0000000 TAB 0000 TAB 09 3. Word address format N50 G00 X2400 Y12 Z0 F0 N60 G01 Z-10000 F500 M08 N70 G00 Z0 M09

Modal commands: Commands issued in the NC program that will stay in effect until it is changed by some other command, like, feed rate selection, coolant selection, etc. :

Modal commands: Commands issued in the NC program that will stay in effect until it is changed by some other command, like, feed rate selection, coolant selection, etc. Non-modal commands: Commands that are effective only when issued and whose effects are lost for subsequent commands, like, a dwell command which instructs the tool to remain in a given configuration for a given amount of time.

Informatıon needed by a CNC:

Informatıon needed by a CNC Preparatory Information: units, incremental or absolute positioning Coordinates: X,Y,Z, RX,RY,RZ Machining Parameters: Feed rate and spindle speed Coolant Control: On/Off, Flood, Mist Tool Control: Tool and tool parameters Cycle Functions: Type of action required Miscellaneous Control: Spindle on/off, direction of rotation, stops for part movement This information is conveyed to the machine through a set of instructions arranged in a desired sequence – Program.

Block Format Sample Block:

Block Format Sample Block N135 G01 X1.0 Y1.0 Z0.125 F5 Restrictions on CNC blocks Each may contain only one tool move Each may contain any number of non-tool move G-codes Each may contain only one feed rate Each may contain only one specified tool or spindle speed The block numbers should be sequential Both the program start flag and the program number must be independent of all other commands (on separate lines) The data within a block should follow the sequence shown in the above sample block

Word-address Codıng:

Word-address Codıng N5 G90 G20 N10 M06 T3 N15 M03 S1250 N20 G00 X1 Y1 N25 Z0.1 N30 G01 Z-0.125 F5 N35 X3 Y2 F10 N40 G00 Z1 N45 X0 Y0 N50 M05 N55 M30 Example CNC Program Each instruction to the machine consists of a letter followed by a number. Each letter is associated with a specific type of action or piece of information needed by the machine. Letters used in Codes N,G,X,Y,Z,A,B,C,I,J,K,F,S,T,R,M

G & M Codes:

G & M Codes N5 G90 G20 N10 M06 T3 N15 M03 S1250 N20 G00 X1 Y1 N25 Z0.1 N30 G01 Z-0.125 F5 N35 X3 Y2 F10 N40 G00 Z1 N45 X0 Y0 N50 M05 N55 M30 Example CNC Program G-codes : Preparatory Functions involve actual tool moves. M-codes : Miscellaneous Functions – involve actions necessary for machining (i.e. spindle on/off, coolant on/off).

G Codes:

G Codes G00 Rapid traverse G01 Linear interpolation G02 Circular interpolation, CW G03 Circular interpolation, CCW G04 Dwell G08 Acceleration G09 Deceleration G17 X-Y Plane G18 Z-X Plane G19 Y-Z Plane G20 Inch Units (G70) G21 Metric Units (G71) G40 Cutter compensation – cancel G41 Cutter compensation – left G42 Cutter compensation – right G70 Inch format G71 Metric format G74 Full-circle programming OFF G75 Full-circle programming ON G80 Fixed-cycle cancel G81- G89 Fixed cycles G90 Absolute dimensions G91 Incremental dimensions

Modal G-Codes:

Modal G-Codes Most G-codes set the machine in a “mode” which stays in effect until it is changed or cancelled by another G - code. These commands are called “modal”. G00 Rapid Transverse G01 Linear Interpolation G02 Circular Interpolation, CW G03 Circular Interpolation, CCW G17 XY Plane G18 XZ Plane G19 YZ Plane G20/G70 Inch units G21/G71 Metric Units G40 Cutter compensation cancel G41 Cutter compensation left G42 Cutter compensation right G43 Tool length compensation (plus) G43 Tool length compensation (plus) G44 Tool length compensation (minus) G49 Tool length compensation cancel G80 Cancel canned cycles G81 Drilling cycle G82 Counter boring cycle G83 Deep hole drilling cycle G90 Absolute positioning G91 Incremental positioning

M Codes:

M Codes M00 Program stop M01 Optional program stop M02 Program end M03 Spindle on clockwise M04 Spindle on counterclockwise M05 Spindle stop M06 Tool change M08 Coolant on M09 Coolant off M10 Clamps on M11 Clamps off M30 Program stop, reset to start

N Codes:

N Codes Gives an identifying number for each block of information. It is generally good practice to increment each block number by 5 or 10 to allow additional blocks to be inserted if future changes are required.

X,Y, and Z Codes:

X,Y, and Z Codes X, Y, and Z codes are used to specify the coordinate axis. Number following the code defines the coordinate at the end of the move relative to an incremental or absolute reference point.

I,J, and K Codes:

I,J, and K Codes I, J, and K codes are used to specify the coordinate axis when defining the center of a circle. Number following the code defines the respective coordinate for the center of the circle.

F,S, and T Codes:

F , S , and T Codes F-code: used to specify the feed rate S-code: used to specify the spindle speed T-code: used to specify the tool identification number associated with the tool to be used in subsequent operations.

Application of Some Codes G01 Linear Interpolation:

Application of Some Codes G01 Linear Interpolation Format: N_ G01 X_ Y_ Z_ F_ Linear Interpolation results in a straight line feed move. Unless tool compensation is used, the coordinates are associated with the centerline of the tool. As an example, for the motion that occurs in x-y plane with the same maximum speed for the x- and y-axis, initial motion is at an angle of 45 o to the axes until motion in one of the axes is completed and then the balance of the motion occurs in the other axis. This is called point-to-point motion .

Application of Some Codes G01 Linear Interpolation:

Application of Some Codes G01 Linear Interpolation G01 is another preparatory function to specify that the tool should be moved to a specified location along a straight line path. It is referred to as linear interpolation. This function is typically used to specify machining of straight features such as turning a cylindrical surface in turning, cutting a slot in milling, etc.

Application of Some Codes G01 Linear Interpolation:

Application of Some Codes G01 Linear Interpolation N10 G00 X1 Z 1 N 1 5 Z0.1 N 20 G01 Z-0.125 F5 N 2 5 X2 Z2 F10 X Z

G02 Circular Interpolation:

G02 Circular Interpolation G02 is also a preparatory function to specify that the tool should be moved to a specified location along a circular path in a clockwise direction. In order to specify the path to the MCU, the end point of the arc and the location of the center of the arc should be specified. Within the block in which the G02 code is programmed, the center of the arc is given by specifying its location relative to the start of the arc.

G02 Circular Interpolation (CW):

G02 Circular Interpolation (CW) G02 command requires an endpoint and a radius in order to cut the arc. I,J, and K are relative to the start point. N_ G02 X2 Y1 I0 J-1 F10 or N_ G02 X2 Y1 R1

Slide 89:

The sequence of some machining operations is may be the same for any part and for any machine. For example, drilling a hole involves the following steps: Position the tool above the point where the hole will be drilled Set the correct spindle speed Feed the tool into the workpiece at a controlled feed rate to a predetermined depth Retract the tool at a rapid rate to just above the point where the hole started Canned Cycles

Slide 90:

Some Commonly Used Canned Cycles Code Function Down feed At bottom Retraction G81 Drilling Continuous feed No action Rapid G82 Spot face, counterbore Continuous feed Dwell Rapid G83 Deep hole drilling Peck No action Rapid G84 Tapping Continuous feed Reverse spindle Feed rate G85 Through boring (in & out) Continuous feed No action Feed rate G86 Through boring (in only) Continuous feed Stop spindle Rapid

G81 Illustration:

G81 Illustrat i on

Three Main parts of a CNC program:

Three Main parts of a CNC program N5 G90 G2 1 (Absolute units, metric ) N10 M06 T2 (Stop for tool change, use tool # 2) N15 M03 S1200 (Turn the spindle on CW to 1200 rpm) Part 1 - Program S etup

Three Main parts of a CNC program:

Three Main parts of a CNC program N20 G00 X1 Y1 (Rapid to X1,Y1 from origin point) N25 Z0.125 (Rapid down to Z0.125) N30 G01 Z-0.125 F 100 (Feed down to Z-0.125 at 100 mm/ m in ) N35 G01 X2 Y2 (Feed diagonally to X2,Y2) N40 G00 Z1 (Rapid up to Z1) N45 X0 Y0 (Rapid to X0,Y0) Part 2- Chip Removal

Three Main parts of a CNC program:

Three Main parts of a CNC program N50 M05 (Turn the spindle off) N55 M 0 0 ( P rogram stop ) Part 3- System Shutdown

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne f 40 f 20 f 10 30 40 100 W R f 42 15+100 +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne [Billet X42 Z115 * Billet size O 1234 * Program Number [STEP * Step-wise run N010 G95 / G94 N020 M06 T01 M03 S600 M08 G94 – feed/min G95 – feed/rev M06 – tool change M03 – spindle forward(cw) M08 – coolant ON W R f 42 15+100 +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N030 G00 X45 Z-1 *Diametral W R f 42 15+100 +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N030 G00 X45 Z-1 *Diametral N040 G01 X0 F0.2 *Facing (move upto -1 if needed) W R f 42 15+100 +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N030 G00 X45 Z-1 *Diametral N040 G01 X0 F0.2 *Facing (move upto -1 if needed) N050 G00 Z2 W R f 42 15+100 +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N030 G00 X45 Z-1 *Diametral N040 G01 X0 F0.2 *Facing (move upto -1 if needed) N050 G00 Z2 N060 G00 X40 W R f 42 15+100 +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N030 G00 X45 Z-1 *Diametral N040 G01 X0 F0.2 *Facing (move upto -1 if needed) N050 G00 Z2 N060 G00 X40 N070 G01 Z-101 F0.2 W R 15+100 +Z f 40

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N030 G00 X45 Z-1 *Diametral N040 G01 X0 F0.2 *Facing (move upto -1 if needed) N050 G00 Z2 N060 G00 X40 N070 G01 Z-101 F0.2 N080 G00 X45 W R 15+100 +Z f 40

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N030 G00 X45 Z-1 *Diametral N040 G01 X0 F0.2 *Facing (move upto -1 if needed) N050 G00 Z2 N060 G00 X40 N070 G01 Z-101 F0.2 N080 G00 X45 N090 G00 Z1 W R 15+100 +Z f 40

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N030 G00 X45 Z-1 *Diametral N040 G01 X0 F0.2 *Facing (move upto -1 if needed) N050 G00 Z2 N060 G00 X40 N070 G01 Z-101 F0.2 N080 G00 X45 N090 G00 Z1 N100 G00 X30 W R 15+100 +Z f 40

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N030 G00 X45 Z-1 *Diametral N040 G01 X0 F0.2 *Facing (move upto -1 if needed) N050 G00 Z2 N060 G00 X40 N070 G01 Z-101 F0.2 N080 G00 X45 N090 G00 Z1 N100 G00 X30 N110 G01 Z-71 F0.2 W R 15+100 +Z f 30

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N030 G00 X45 Z-1 *Diametral N040 G01 X0 F0.2 *Facing (move upto -1 if needed) N050 G00 Z2 N060 G00 X40 N070 G01 Z-101 F0.2 N080 G00 X45 N090 G00 Z1 N100 G00 X30 N110 G01 Z-71 F0.2 N120 G00 X42 *Facing W R 15+100 +Z f 30

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N030 G00 X45 Z-1 *Diametral N040 G01 X0 F0.2 *Facing (move upto -1 if needed) N050 G00 Z2 N060 G00 X40 N070 G01 Z-101 F0.2 N080 G00 X45 N090 G00 Z1 N100 G00 X30 N110 G01 Z-71 F0.2 N120 G00 X42 *Facing N130 G00 Z1 W R 15+100 +Z f 30

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N030 G00 X45 Z-1 *Diametral N040 G01 X0 F0.2 *Facing (move upto -1 if needed) N050 G00 Z2 N060 G00 X40 N070 G01 Z-101 F0.2 N080 G00 X45 N090 G00 Z1 N100 G00 X30 N110 G01 Z-71 F0.2 N120 G00 X42 *Facing N130 G00 Z1 N140 G00 X20 W R 15+100 +Z f 30

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N030 G00 X45 Z-1 *Diametral N040 G01 X0 F0.2 *Facing (move upto -1 if needed) N050 G00 Z2 N060 G00 X40 N070 G01 Z-101 F0.2 N080 G00 X45 N090 G00 Z1 N100 G00 X30 N110 G01 Z-71 F0.2 N120 G00 X42 *Facing N130 G00 Z1 N140 G00 X20 N150 G01 Z-71 F0.2 W R 15+100 +Z f 20

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N160 G00 X42 W R 15+100 +Z f 20

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N160 G00 X42 N170 G00 Z1 W R 15+100 +Z f 20

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N160 G00 X42 N170 G00 Z1 N180 G00 X15 W R 15+100 +Z f 20

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N160 G00 X42 N170 G00 Z1 N180 G00 X15 N190 G01 Z-31 F0.2 W R 15+100 +Z f 15

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N160 G00 X42 N170 G00 Z1 N180 G00 X15 N190 G01 Z-31 F0.2 N200 G00 X22 W R 15+100 +Z f 15

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N160 G00 X42 N170 G00 Z1 N180 G00 X15 N190 G01 Z-31 F0.2 N200 G00 X22 N210 G00 Z1 W R 15+100 +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N160 G00 X42 N170 G00 Z1 N180 G00 X15 N190 G01 Z-31 F0.2 N200 G00 X22 N210 G00 Z1 N220 G00 X10 W R 15+100 +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N160 G00 X42 N170 G00 Z1 N180 G00 X15 N190 G01 Z-31 F0.2 N200 G00 X22 N210 G00 Z1 N220 G00 X10 N230 G01 Z-31 F0.2 W R 15+100 +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N160 G00 X42 N170 G00 Z1 N180 G00 X15 N190 G01 Z-31 F0.2 N200 G00 X22 N210 G00 Z1 N220 G00 X10 N230 G01 Z-71 F0.2 N240 G00 X22 W R 15+100 +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N250 G28 *go to reference W R 15+100 +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N250 G28 *go to reference N260 M06 T02 *parting-off tool R W 15+100 +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N250 G28 *go to reference N260 M06 T02 *parting-off tool N270 G00 X45 Z-104 * 100+1+3(tool width) R W 15+100 +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N250 G28 *go to reference N260 M06 T02 *parting-off tool N270 G00 X45 Z-104 * 100+1+3(tool width) N280 G00 X42 R W 15+100 +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N250 G28 *go to reference N260 M06 T02 *parting-off tool N270 G00 X45 Z-104 * 100+1+3(tool width) N280 G00 X42 N290 G01 X0 F0.05 *parting-off R +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N250 G28 *go to reference N260 M06 T02 *parting-off tool N270 G00 X45 Z-104 * 100+1+3(tool width) N280 G00 X42 N290 G01 X0 F0.05 *parting-off N300 G28 R +Z

Example Operatıon on CNC Turning Machine:

Example Operatıon on CNC Turning Mach i ne N250 G28 *go to reference N260 M06 T02 *parting-off tool N270 G00 X45 Z-104 * 100+1+3(tool width) N280 G00 X42 N290 G01 X0 F0.05 *parting-off N300 G28 N320 M05 M30 *M05 – spindle stop *M30 – Program stop, reset to start

Advanced features:

Advanced features Execution of the part of the program in a rotated or mirrored position. Ability to scale the program and produce larger or smaller programs. Three dimensional circular interpolation which produces a helical shape. Parabolic and cubic interpolation.

Slide 127:

Through keyboard Through punched tape reader Through diskette drive Through RS 232 serial port Through network interface card Program Loading

Slide 128:

A system in which a central computer downloads the NC programs block by block to many NC machine tools simultaneously is called Direct Numerical Control (DNC) system. This system used to work with the early NC machine tools which can not read more than a block of information at a time. The central computer feed the program information one block at a time. When the machine execute the information, the next block of information would be fed. Direct Numerical Control (DNC)

Slide 129:

Distributed NC is known by the same acronym as Direct Numerical Control (DNC). After the introduction of CNC, the machine tools have had the capability of storing large amount of information. Therefore, there have been no need to have drip feed information system, like, Direct Numerical Control. Instead, Distributed Numerical Control is introduced. In such a system, a host computer communicate with many CNC machine tools via networks and download or upload programs. Direct Numerical Control (DNC)

Slide 130:

With Distributed Numerical Control systems, it is possible to monitor the activities in individual CNC machine tools on host computer. Therefore, better shop floor control can be achieved. NC program preparation may be tedious and difficult if the part to be machined has a complex geometry. The main difficulty is to find out the cutter locations during the machining. Computers may be used to assist the programmers in preparing the NC codes. Direct Numerical Control (DNC)