CNC Programming

PREPARATORY FUNCTIONS (G-Codes)

G00- Rapid transverse
G01- Linear interpolation
G02- Circular interpolation clock wise
G03- Circular interpolation counter clock wise
G04- Dwell time under address for X in seconds
G09- Speed reduction, fine exact positioning
G10- Polar co-ordinates programming rapid traverse
G11- Polar co-ordinates programming linear interpolation
G17- Plane selection XY-plane
G18- Plane selection XZ-plane
G19- Plane selection YZ-plane
G25- Minimum working area limitation
G26- Maximum working area limitation
G33- Thread cutting
G34- Thread cutting, linearly progressive lead
G35- Thread cutting, linearly degressive lead
G40- Cancel cutter radius compensation
G41- cutter radius compensation left
G42- Cutter radius compensation right
G53- Supress the zero offsets
G54- Select zero offset 1
G55- Select zero offset 2
G56- Select zero offset 3
G57- Select zero offset 4
G58- Programmable zero offset 1
G58- Programmable zero offset 2
G59- Programmable additive zero offset
G60- Exact stop
G62- Continuous path operation, block transition with speed reduction
G63- Tapping with compensation CHUCK
G64- Continuous path mode
G70- Input system in inch Reset state
G71- Input system in metric machine data
G80- No boring cycle
G81- Drilling centering boring cycle
G82- Drilling and counter sinking cycle
G83- Deep hole drilling and boring cycle
G84- Tapping cycle
G85- Boring cycle
G86- Boring cycle
G87- Boring cycle
G88- Boring cycle
G89- Boring cycle
G90- Absolute dimension programming
G91- Incremental dimension programming
G92- Limitation of spindle speed “S” when using with G96
G94- Feed rate under address F mm/rev.
G95- Feed rate under address F mm/rev.
G96- constant cutting speed
G97- Cancel G96, store last set speed of G96

MISCELLANEOUS FUNCTIONS [M-Codes]

M00- Un-conditional program stop
M01- Conditional program stop.
M02- End of program with return to program start
M03- Spindle rotation clock-wise
M04- Spindle rotation counter clock-wise
M05- Spindle stop
M06- Turret index
M07- Coolant ON
M08- Coolant ON
M09- Coolant OFF
M10- Chuck close
M11- Chuck open
M13- Coolant ON with spindle ON
M15- Coolant OFF with spindle OFF
M16- Chuck I.D. selection
M17- End of subroutine, written in the lost block of the subroutine
M18- Chuck O.D. selection
M19- Spindle orientation
M20- Cancel mirror image
M21- Mirror image X-axis
M22- Mirror image Y-axis
M23- Mirror image Z-axis
M24- Chip converge FWD
M25- Chip converge Reverse
M26- Chip converge Off
M30- End of program
M32- Tail stock quill forward
M33- Tail stock quill retract
M36- Feed rate over enable
M38- Spindle speed over enable
M41- Spindle gear low
M42- Spindle gear high
M46- Auto door open
M47- Auto door close
M50- Spindle lock
M51- Spindle unlock
M65- Bar feeder ON
M66- Decode before M99
M68- Part catcher IN
M69- Part catcher OUT
M78- Steady rest 1 IN
M79- Steady rest 1 OUT
M80- Steady rest 2 IN
M81- Steady rest 2 OUT
M82- Tail stock body FWD/unclamp
M83- Tail stock body RET/clamp
M84- Touch probe arm forward
M85- Touch probe arm Retract
M98- Subroutine call
M99- Subroutine end

CNC PROGRAMMING

STEPS IN CNC PROCESS (Manual Programming)

1. Review part drawing
2. Decide which machine will produce the part
3. Choose the tooling required
4. Decide on the machining sequence
5. Do math calculations to find part coordinates
6. Calculate the spindle speeds and feed rates required for the tooling and part material
7. Write the CNC program
8. Prepare setup sheets and tool lists
9. Verify the program using a CNC simulator or the actual machine
10. Edit the program if necessary
11. Run the program and produce the part

STEPS IN THE CNC PROCESS (CAM)

1. Develop the three-dimensional geometric model of the part using CAD

2. Decide which machining operations are required to produce the part

3. Choose the tooling to be used

4. Run a CAM software program to generate the CNC part program, including the setup sheets and list of tools

5. Verify the program on a machine simulator

6. Download the part program(s) to the appropriate machine(s)

7. Verify the program(s) on the actual machine(s) and edit if necessary

8. Run the program(s) and produce the part