CNC Lathe Machine Programming - Basic Commands And Examples

CNC (Computer Numerical Control) is the control of a certain machine with the use of symbolic codes consisting of characters and numerals to create a projected design. CNC Machining and Programming has been one of my subjects last year and today I want to impart my knowledge on the basic commands when programming a CNC Project. I will be focusing on CNC Lathe Machine since it is the kind of computer numerical controlled machine that we had been using in our classes a year ago.

Axes

• We are using a 2 axes CNC Lathe Machine so literally there will be 2 axes along which the movement of the tool will take place.

X	Moves the tool vertically
Z	Moves the tool horizontally

Sequence Number

N Adress

• This is used to identify a certain block, it is always placed at the beginning of the block and could be referred to as the name of that block.

Preparatory Function

G Adress

• This determines how the the tool moves to the programmed target. Here are the commonly used G adresses during my experience

WORD	FUNCTION
G00	Rapid Traverse Movement
G01	Linear Interpolation
G02	Clockwise Circular Interpolation
G03	Counter Clockwise Circular Interpolation
G50	Setting Workpiece Coordinated System
G70	Finishing Cycle
G71	Axial Roughing Cycle
G72	Radial Roughing Cycle
G92	Thread Cutting Cycle

Miscellaneous Function

M Adress

• This are programmed to control the machining operation and not for coordinate movement.

WORD	FUNCTION
M3	Spindle Clockwise or Start of Program
M4	Spindle Counter Clockwise
M30	End of Program

Tool Function

T Adress

• This is used to select a certain tool for the programmed target.

WORD	FUNCTION
T01	Represents Tool Number 1
T02	Represents Tool Number 2
T03	Represents Tool Number 3
T04	Represents Tool Number 4

These tool numbers are mainly based on the availability of the tools in your CNC Lathe Machine's Tool Turret.

Spindle Function

S Adress

• This commands the spindle speed and is measured in revolutions per minute.

WORD	FUNCTION
S800	Spindle Speed at 800 RPM (Revolutions Per Minute)
S1000	Spindle Speed at 1000 RPM (Revolutions Per Minute)
S1200	Spindle Speed at 1200 RPM (Revolutions Per Minute)

Examples

• Here is an example of one of our activities before in which we are tasked to draw the figure that the program should output.
  

• In this example we are tasked to give the correct program to display this output.
  

Here is the code that I made for this figure:

M3
T0303
S1000
G00 X30 Z5
G00 X0 Z5
G01 X0 Z0
G03 X10 Z-4.5 R5
G03 X6 Z-9 R5
G01 X6 Z-11
G02 X11 Z-21 R22
G03 X17 Z-24 R3
G03 X24 Z-26.5 R2.5
G01 X25 Z-26.5
G01 X25 Z-29
G00 X30 Z-29
G00 X30 Z5
M30

Conclusion

CNC Machining and Programming is a great skill to possess since it is very in demand in the field. It is a great privilege for us mechanical engineering students to have known and develop this skill.

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My greatest thanks to Engr. Orlene Balungkas for teaching us trainees about CNC Machining and Programming. One thing I could never forget about, was having a present from him on our final examination. He challenged us to have a perfect score for the exam and however gets perfect and had submitted first will get to have a pre-loved NBA Jersey from him. So I strived hard to earn that reward and so I did. Im happy to have a remembrance of his great effort in teaching us and I'd treasure it as a sign of my respect for him. He is a great instructor and I looked up on him.

Here is the pre-loved jersey that I received from him, a Golden States Warriors Stephen Curry Jersey.

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