CNC Programming

The code which controls the CNC machine.

CNC ProgrammingCNC Programming

NC Code Sample NC Part and Program M Codes G Code

NC Code ComponentsNC Code Components

Lines of NC code contain instructions for the machine to follow.

Some of the instructionsprepare the machine tell the machine where to send the tooland control accessories on the machine.

NC Code ComponentsNC Code Components Block Number (N)

Is the line number within the program Preparatory Codes (G)

Prepare the machine to perform an operation Miscellaneous Codes (M)

Perform miscellaneous functions within the program

NC Code ComponentsNC Code Components

Primary X Motion (X) Instructs the machine to move the tool to this X coordinate.

Primary Y Motion (Y) Instructs the machine to move the tool to this Y coordinate.

Primary Z Motion (Z) Instructs the machine to move the tool to this Z coordinate.

Preparatory: G-CodesPreparatory: G-Codes

G90 - Absolute Coordinates – makes all coordinates relative to the origin

G91 – Incremental Coordinates – makes new coordinates relative to the last point.

G00 - Rapid Traverse (non-cutting move) – move the tool at the maximum rate of feed

Preparatory: G-CodesPreparatory: G-Codes

G01 - Straight Line Interpolation – move the tool in a straight line to the desired coordinates

G02 - Circular Interpolation CW – move the tool in a clockwise direction through an arc

G03 – Circular Interpolation CCW – move the tool in a counter-clockwise direction through an arc

Miscellaneous: M CodesMiscellaneous: M Codes

M02 - End of Program M03 - Spindle on [speed to follow (e.g.

S3000)] M05 - Spindle off M08/M09 Accessory 1 on/off M10/M11 Accessory 2 on/off

Sample NC Program Block

Sample NC Program Block

N00 G90

BLOCK SEQUENCE #

PREP CODE – ABSOLUTE COORDINATES

Sample NC Program BlockSample NC Program Block

PREP CODE – S.L. INTERPOLATION

N01 G01

Sample NC Program BlockSample NC Program Block

X COORDINATE

Y COORDINATE

Z COORDINATE

FEED RATE (IN/MIN)

N02 X.5 Y.5 Z0 F1

SAMPLE PARTSAMPLE PART

ABSOLUTE COORD.

A 0.5 0.5

B 0.5 1.5C 0.8751D 1.25 1.5E 1.25 0.5F 1.75 1.5H 1.75 0.5I 1.75 1

SAMPLE PROGRAMSAMPLE PROGRAMN00 G90 ;ABSOLUTE COORDINTAESN01 G01 ;STRAIGHT LINE INTERPOLATIONN02 T1M06 ;LOAD TOOL 1N03 M03 S3000 ;TURN SPINDLE ON TO 3000 RPMN04 G00 X.5Y.5 ;RAPID TO POINT A N05 G00 Z .1 ;RAPID TO .1 ABOVE PARTN06 Z-.0625F9 ;PLUNGE AT 9 IN/MIN.N07 X.5Y1.5 ;MOVE TO BN08 X.875Y1 ;MOVE TO CN09 X1.25Y1.5 ;MOVE TO DN10 X1.25Y.5 ;MOVE TO EN11 Z.1 ;RETRACT CUTTING TOOL

Sample Program Continued

Sample Program ContinuedN12 G00 X1.75Y1.5 ;RAPID TO POINT F

N13 Z-.0625F9 ;PLUNGE AT 9 IN/MIN.N14 X1.75Y.5 ;MOVE TO HN15 N16 G03 X1.75Y1.5I1.75J1 ;CCW CIRCLE INTER.

;CUT THE ARC TO X1.75Y1.5;WITH CIR CENTER AT X1.75Y1

N17 G01Z.1 ;RETRACT CUTTING TOOLN18 M05 ;TURN OFF SPINDLEN19 T00M06 ;UNLOAD CUTTING TOOLN20 M02 ;END OF PROGRAM