CNC G Code

G-Codes Simple Definition

G00     Rapid traverse
G01     Linear interpolation with feedrate
G02     Circular interpolation (clockwise)
G03     Circular interpolation (counter clockwise)
G2/G3   Helical interpolation
G04     Dwell time in milliseconds
G05     Spline definition
G06     Spline interpolation
G07     Tangential circular interpolation / Helix interpolation / Polygon interpolation /             Feedrate interpolation
G08     Ramping function at block transition / Look ahead "off"
G09     No ramping function at block transition / Look ahead "on"
G10     Stop dynamic block preprocessing
G11     Stop interpolation during block preprocessing
G12     Circular interpolation (cw) with radius
G13     Circular interpolation (ccw) with radius
G14     Polar coordinate programming, absolute
G15     Polar coordinate programming, relative
G16     Definition of the pole point of the polar coordinate system
G17     Selection of the X, Y plane
G18     Selection of the Z, X plane
G19     Selection of the Y, Z plane
G20     Selection of a freely definable plane
G21     Parallel axes "on"
G22     Parallel axes "off"
G24     Safe zone programming; lower limit values
G25     Safe zone programming; upper limit values
G26     Safe zone programming "off"
G27     Safe zone programming "on"
G33     Thread cutting with constant pitch
G34     Thread cutting with dynamic pitch
G35     Oscillation configuration
G38     Mirror imaging "on"
G39     Mirror imaging "off"
G40     Path compensations "off"
G41     Path compensation left of the work piece contour
G42     Path compensation right of the work piece contour
G43     Path compensation left of the work piece contour with altered approach
G44     Path compensation right of the work piece contour with altered approach
G50     Scaling
G51     Part rotation; programming in degrees
G52     Part rotation; programming in radians
G53     Zero offset off
G54     Zero offset #1
G55     Zero offset #2
G56     Zero offset #3
G57     Zero offset #4
G58     Zero offset #5
G59     Zero offset #6
G63     Feed / spindle override not active
G66     Feed / spindle override active
G70     Inch format active
G71     Metric format active
G72     Interpolation with precision stop "off"
G73     Interpolation with precision stop "on"
G74     Move to home position
G75     Curvature function activation
G76     Curvature acceleration limit
G78     Normalcy function "on" (rotational axis orientation)
G79     Normalcy function "off"

G80 - G89 for milling applications:
G80     Canned cycle "off"
G81     Drilling to final depth canned cycle
G82     Spot facing with dwell time canned cycle
G83     Deep hole drilling canned cycle
G84     Tapping or Thread cutting with balanced chuck canned cycle
G85     Reaming canned cycle
G86     Boring canned cycle
G87     Reaming with measuring stop canned cycle
G88     Boring with spindle stop canned cycle
G89     Boring with intermediate stop canned cycle

G81 - G88 for cylindrical grinding applications:

G81     Reciprocation without plunge
G82     Incremental face grinding
G83     Incremental plunge grinding
G84     Multi-pass face grinding
G85     Multi-pass diameter grinding
G86     Shoulder grinding
G87     Shoulder grinding with face plunge
G88     Shoulder grinding with diameter plunge
G90     Absolute programming
G91     Incremental programming
G92     Position preset
G93     Constant tool circumference velocity "on" (grinding wheel)
G94     Feed in mm / min (or inch / min)
G95     Feed per revolution (mm / rev or inch / rev)
G96     Constant cutting speed "on"
G97     Constant cutting speed "off"
G98     Positioning axis signal to PLC
G99     Axis offset
G100   Polar transformation "off"
G101   Polar transformation "on"
G102   Cylinder barrel transformation "on"; cartesian coordinate system
G103   Cylinder barrel transformation "on," with real-time-radius compensation         (RRC)
G104   Cylinder barrel transformation with center line migration (CLM) and RRC
G105   Polar transformation "on" with polar axis selections
G106   Cylinder barrel transformation "on" polar-/cylinder-coordinates
G107   Cylinder barrel transformation "on" polar-/cylinder-coordinates with RRC
G108   Cylinder barrel transformation polar-/cylinder-coordinates with CLM and         RRC
G109   Axis transformation programming of the tool depth
G110   Power control axis selection/channel 1
G111   Power control pre-selection V1, F1, T1/channel 1 (Voltage, Frequency, Time)
G112   Power control pre-selection V2, F2, T2/channel 1
G113   Power control pre-selection V3, F3, T3/channel 1
G114   Power control pre-selection T4/channel 1
G115   Power control pre-selection T5/channel 1
G116   Power control pre-selection T6/pulsing output
G117   Power control pre-selection T7/pulsing output
G120   Axis transformation; orientation changing of the linear interpolation rotary     axis
G121   Axis transformation; orientation change in a plane
G125   Electronic gear box; plain teeth
G126   Electronic gear box; helical gearing, axial
G127   Electronic gear box; helical gearing, tangential
G128   Electronic gear box; helical gearing, diagonal
G130   Axis transformation; programming of the type of the orientation change
G131   Axis transformation; programming of the type of the orientation change
G132   Axis transformation; programming of the type of the orientation change
G133   Zero lag thread cutting "on"
G134   Zero lag thread cutting "off"
G140   Axis transformation; orientation designation work piece fixed coordinates
G141   Axis transformation; orientation designation active coordinates
G160   ART activation
G161   ART learning function for velocity factors "on"
G162   ART learning function deactivation
G163   ART learning function for acceleration factors
G164   ART learning function for acceleration changing
G165   Command filter "on"
G166   Command filter "off"
G170   Digital measuring signals; block transfer with hard stop
G171   Digital measuring signals; block transfer without hard stop
G172   Digital measuring signals; block transfer with smooth stop
G175   SERCOS-identification number "write"
G176   SERCOS-identification number "read"
G180   Axis transformation "off"
G181   Axis transformation "on" with not rotated coordinate system
G182   Axis transformation "on" with rotated / displaced coordinate system
G183   Axis transformation; definition of the coordinate system
G184   Axis transformation; programming tool dimensions
G186   Look ahead; corner acceleration; circle tolerance
G188   Activation of the positioning axes
G190   Diameter programming deactivation
G191   Diameter programming "on" and display of the contact point
G192   Diameter programming; only display contact point diameter
G193   Diameter programming; only display contact point actual axes center point
G200   Corner smoothing "off"
G201   Corner smoothing "on" with defined radius
G202   Corner smoothing "on" with defined corner tolerance
G203   Corner smoothing with defined radius up to maximum tolerance
G210   Power control axis selection/Channel 2
G211   Power control pre-selection V1, F1, T1/Channel 2
G212   Power control pre-selection V2, F2, T2/Channel 2
G213   Power control pre-selection V3, F3, T3/Channel 2
G214   Power control pre-selection T4/Channel 2
G215   Power control pre-selection T5/Channel 2
G216   Power control pre-selection T6/pulsing output/Channel 2
G217   Power control pre-selection T7/pulsing output/Channel 2
G220   Angled wheel transformation "off"
G221   Angled wheel transformation "on"
G222   Angled wheel transformation "on" but angled wheel moves before others
G223   Angled wheel transformation "on" but angled wheel moves after others
G265   Distance regulation – axis selection
G270   Turning finishing cycle
G271   Stock removal in turning
G272   Stock removal in facing
G274   Peck finishing cycle
G275   Outer diameter / internal diameter turning cycle
G276   Multiple pass threading cycle
G310   Power control axes selection /channel 3
G311   Power control pre-selection V1, F1, T1/channel 3
G312   Power control pre-selection V2, F2, T2/channel 3
G313   Power control pre-selection V3, F3, T3/channel 3
G314   Power control pre-selection T4/channel 3
G315   Power control pre-selection T5/channel 3

G316   Power control pre-selection T6/pulsing output/Channel 3
G317   Power control pre-selection T7/pulsing output/Channel 3

Note that some of the above G-codes are not standard. Specific control features, such as laser power control, enable those optional codes. 

CNC ALPHABET

• A

Absolute or incremental position of A axis (rotational axis around X axis)

• B

Absolute or incremental position of B axis (rotational axis around Y axis)

• C

Absolute or incremental position of C axis (rotational axis around Z axis)

• D

Defines diameter or radial offset used for cutter compensation. D is used for depth of cut on lathes.

• E

Precision feedrate for threading on lathes

• F

Defines feed rate Common units are distance per time for mills (inches per minute, IPM, or millimetres per minute, mm/min) and distance per revolution for lathes (inches per revolution, IPR, or millimetres per revolution, mm/rev)

• G

Address for preparatory commands G commands often tell the control what kind of motion is wanted (e.g., rapid positioning, linear feed, circular feed, fixed cycle) or what offset value to use.

• H

Defines tool length offset; Incremental axis corresponding to C axis (e.g., on a turn-mill)

• I

Defines arc center in X axis for G02 or G03 arc commands. Also used as a parameter within some fixed cycles.

• J

Defines arc center in Y axis for G02 or G03 arc commands. Also used as a parameter within some fixed cycles.

• K

Defines arc center in Z axis for G02 or G03 arc commands. Also used as a parameter within some fixed cycles, equal to L address.

• L

Fixed cycle loop count; Specification of what register to edit using G10 Fixed cycle loop count: Defines number of repetitions ("loops") of a fixed cycle at each position. Assumed to be 1 unless programmed with another integer. Sometimes the K address is used instead of L. With incremental positioning ( G91), a series of equally spaced holes can be programmed as a loop rather than as individual positions. G10 use: Specification of what register to edit (work offsets, tool radius offsets, tool length offsets, etc.).

• M

Miscellaneous function Action code, auxiliary command; descriptions vary. Many M-codes call for machine functions, which is why people often say that the "M" stands for "machine", although it was not intended to.

• N

Line (block) number in program; System parameter number to be changed using G10 Line (block) numbers: Optional, so often omitted. Necessary for certain tasks, such as M99 P address (to tell the control which block of the program to return to if not the default one) or G.T. statements (if the control supports those). N numbering need not increment by 1 (for example, it can increment by 10, 20, or 1000) and can be used on every block or only in certain spots throughout a program. System parameter number: G10 allows changing of system parameters under program control.

• O

Program name For example, O4501. For many years it was common for CNC control displays to use slashed zero glyphs to ensure effortless distinction of letter "O" from digit "0". Today's GUI controls often have a choice of fonts, like a PC does.

• P

Serves as parameter address for various G and M codes With G04, defines dwell time value. Also serves as a parameter in some canned cycles, representing dwell times or other variables. Also used in the calling and termination of subprograms. (With M98 , it specifies which subprogram to call; with M99, it specifies which block number of the main program to return to.)

• Q

Peck increment in canned cycles. For example, G73 , G83 (peck drilling cycles)

• R

Defines size of arc radius, or defines retract height in milling canned cycles For radiuses, not all controls support the R address for G02 and G03, in which case IJK vectors are used. For retract height, the "R level", as it's called, is returned to if G99 is programmed.

• S

Defines speed , either spindle speed or surface speed depending on mode Data type = integer. In G97 mode (which is usually the default), an integer after S is interpreted as a number of rev/min (rpm). In G96 mode (CSS), an integer after S is interpreted as surface speed —sfm ( G20 ) or m/min (G21 ). See also Speeds and feeds . On multifunction (turn-mill or mill-turn) machines, which spindle gets the input (main spindle or subspindles) is determined by other M codes.

• T

Tool selection To understand how the T address works and how it interacts (or not) with M06 , one must study the various methods, such as lathe turret programming, ATC fixed tool selection, ATC random memory tool selection, the concept of "next tool waiting", and empty tools. Programming on any particular machine tool requires knowing which method that machine uses. Ways of obtaining this training are mentioned in the comments for M06.

• U

Incremental axis corresponding to X axis (typically only lathe group A controls) Also defines dwell time on some machines (instead of " P " or " X "). In these controls, X and U obviate G90 and G91 , respectively. On these lathes, G90 is instead a fixed cycle address for roughing .

• V

Incremental axis corresponding to Y axis Until the 2000s, the V address was very rarely used, because most lathes that used U and W didn't have a Y- axis, so they didn't use V. (Green et al. 1996 did not even list V in their table of addresses.) That is still often the case, although the proliferation of live lathe tooling and turn-mill machining has made V address usage less rare than it used to be. See also G18 .

• W

Incremental axis corresponding to Z axis (typically only lathe group A controls) In these controls, Z and W obviate G90 and G91 , respectively. On these lathes, G90 is instead a fixed cycle address for roughing .

• X

Absolute or incremental position of X axis. Also defines dwell time on some machines (instead of " P " or " U ").

• Y

Absolute or incremental position of Y axis

• Z

Absolute or incremental position of Z axis The main spindle's axis of rotation often determines which axis of a machine tool is labeled as Z.

Computer Aided Drafting And Design (CADD)

Definition

Computer Aided Drafting And Design (CADD) is the computer process of making engineering drawing and technical documents more closely related to drafting.

• What is CADD ?

Computer Aided Drawing is a technique where engineering drawings are produced with the assistance of computer and, as with manual drawing, is only the graphical means of representing a design.
Computer Aided Design, however, is a technique where the attributes of the computer and those of the designer are blended together into a problem solving term.

• Two Dimensional (2D) CAD

Computer drawing is the representation of an object in the single view format which shows two of the three object dimensions or the multi view format where each view reveals two dimensions.

 

• Three Dimensional (3D) CAD

Computer drawing is the coordinate format. Three dimensional computer aided drawing allows the production of geometric models of a component or product for spatial and visual analysis.

• Advantages Of CADD

• Drafting Stage

1. Increased accuracy
2. Increased drawing speed
3. Easy to revise
4. Availability of drawing libraries
5. Constant drawing quality
6. Multicolor drawing
7. Built in several analysis tools
8. Better presentation (Easy To Visualize)-Pan, Rotate, Animate, Shade, Texture
9. Save on repetition

• CADD Capability

1. Draw
2. Modify
3. Dimension
4. Object snap
5. Layer concept

• Concepts In Working Drawing Creation

2-D CADD

• Draw a group of line that are connected and present

- Orthographic multiview

- Pictorial view

Solid Modeling

• Draw a closed contour and convert to surface.
• Modify this surface to solid object.
• Create an orthographic view from a solid object.

• Limitation Of CADD

Good engineering drawing must have the following characteristics.

• Part or product information is completely given.
• Information is clearly presented.
• Information can be used in manufacturing of part.

Always remind yourself that

"Good drawing cannot be created by using CADD software alone without understanding the drawing concept." 

• Limitation Of CADD (with in scope of drawing creation)

To create a good engineering drawings You must do the following tasks yourself.

1. Apply a proper line weight and style.
2. Select a necessary view.
3. Decide the appropriate places of dimensions.
4. Select an appropriate section techniques.

• Limitation Of CADD (with in scope of drawing interpretation)

No CADD software can create a pictorial view from an orthographic multiview.

Because they are frequently used technical document. Therefore,You must prepare your self for interpreting (or visualizing) them when you become an Engineer.

• Modern System In CADD

Tn modern system the light pen has been replaced by more effective pointing hardware, that is a digitizer tablet, a mouse.

CADD System And Hardware

1. The mainframe computer
2. The minicomputer
3. The Microcomputer

Input Devices

The input devices are used for making selections from a menu, which is a layout of a variety of commands and functions required to operate the system. Sending these command into the computer produces complete engineering drawing.

• Modern System In CADD

1. Impact printer (dot matrix)
2. Non-impact printer include electrostatic, ink-jet and laser
3. Flatbed plotters
4. Drum plotters

• User Interface

CAD systems may be considered as comprising a large number of functions for creating or manipulating the design model. Traditionally, there are two ways in which this is achieved:

Command-based systems

Command-based systems operate by reading a command and its parameters entered by the user, carrying out the required actions, then waiting for the next command.

• User Interface – Menu Driven

The menu-driven approach contrasts markedly with the command

approach. The basic principle is that the user is at any time

presented with a list or menu of the functions that are available

to be selected.

Rules

• The most important of these rules are:
• A clear, well presented screen layout.
• Easy function selection by a well-structured menu system.
• Meaningful function names.
• Meaningful and helpful prompts to the user.
• Easily accessible and clearly written help information.

• CADD Functionality

The main benefits of a computerized drafting and design system over those of manual methods is this ability to represent the design of a component or assembly in a geometrically accurate format so that the same model can be used for other modelling, analysis and manufacturing work.

The functions can be said to fall into three categories:

• Synthesis type functions are concerned mainly with the creation of geometric features and drawing details.
• Modification functions include those which allow for the deletion and editing of existing geometry or detail.
• Management functions are concerned with how the drawing is presented both on the screen and eventually on paper.

• CADD System Selection

There is a large variety of different CADD packages available on the market these days and the design manager is faced with the enormous problem of selecting a package to suit the demands

of the company and its product range. A lot of ease and efficiency has been obtained with the use of CADD systems. Among the more widely used CAD systems are AutoCAD, CATIA, SolidWorks, I-DEAS, and ProEngineer. Most of these packages have both a 2D and 3D component or have an integrated 2D and 3D modeling system. The newer versions of drawing software operate under a menu system which can be accessed through keyboard input or mouse manipulation.

• CADD System Selection

According to these factors, the system must have;

• Functional abilities: the abilities to perform memory circuits.
• Memory capacity : evaluation between main and branch memory circuits.
• Data transfer characteristics : when we consider data transfer between two computers, or a main computer and a station, we have to keep in mind the need to decrease computing time

• CADD System Selection

The size of the company and the amount of investment capital available will be one of the main deciding factors but there are many other questions to be considered:

Mainframe or PC/workstation platform?

Two dimensions or three? Lines, surfaces or solids?

Other analysis tools needed? Will the ability to transfer the

geometry to these modelling and analysis systems be needed?

Compatibility with other systems needed?

How good is the maintenance and support from the suppliers?

How much, how good and how long is the training?

How easy is it to expand the system?

• AutoCAD

AutoCAD is PCbased

CAD software products (late 1982).

System Requirements for AutoCAD

Windows NT or Windows 95/98/2000

Intel 486 or Pentium processor or compatible

32 MB of RAM

50 MB of hard disk space

64MB of disk swap space

2.5 MB of free disk space during installation only

CD-ROM drive

640 x 480 VGA video display (1024 x 768 recommended)

Windows-supported display adapter

Mouse or other pointing device