G04

G04- Dwell Time:

        It is used for stopping the tool movement for a specified time.

Commonly G04 is used to

       Hold the axis movements until the chuck rotates in the given r.p.m.
       Hold the axis movements until the coolant gets the required pressure.
       Getting a good surface finishing by allowing the tool to wait for a while before it goes to the next destination.
      

Ex:-

For 2 Seconds delay -

G04 X2.0;

or

G04 U2.0; 

or

G04 P2000; 

G02 and G03

G02:  Clock Wise Movement of the tool.

It is used for making a radius in the component using clockwise motion of the tool.

Format: G02X---Z----R----F-----

G03:  Counter Clock Wise Movement of the tool.

It is used for making a radius in the component using Counter clockwise motion of the tool.

Format: G03X---Z----R----F-----

Lesson-7-G-Codes-G00,G01

List of G codes:

G codes are Preparatory commends :

G00 - Rapid traverse:

It is used for fast movements of the tool when it is not engaged with the job.
In the below picture tool moves from point 1 to 2 rapidly .we can use G00 here why because
tool is not doing any operation in the work piece.

Format : G00X---Z----

G01:- Linear Interpolation:

It is used for tool movements with feed rate when tool is doing some operations
on the work piece.

Format : G01X---Z----F----

Lesson-6 : Control panel

CNC Turning Machine's Control panel:
We will learn about the control panel keys in the coming lessons.

ON--------------------------------------Power on Switch
OFF-------------------------------------Power off Switch
Emergency Stop --------------------- Turns off power
Cycle Start ----------------------------Starts Program Execution
Feed Hold ---------------------------- Stops tool motion
Optional Stop ------------------------ Stops the program when M01 is in the
                                                        program
Dry Run -------------------------------For testing programs without part
Chuck Clamp ------------------------ Shows chuck clamping status
Block Slip ---------- ------------------Skips blocks with / symbol
Spindle Rotation ---------------------Indicates the direction of the spindle
Tool change-------------------------- For manual tool change
Handle -------------------------------- Manual Pulse Generator (MPG) for axis
                                                    selection and movement
MDI ----------------------------------- Manual data input
Auto----------------------------------- Automatic operations
Edit ----------------------------------- For doing changes in a program
Jog ------------------------------------ Selecting jog mode for movements

Lesson-5 : Some important Symbols:

Some important Symbols:

Symbols	Description	Comment
.	Decimal point	Fractional part of a number
+	Plus sign	Positive value or addition sign in Fanuc macros
-	Minus sign	Negative value or subtraction sign in Fanuc macros
*	Multiplication sign	Multiplication sign in Fanuc macros
/	Slash ( Front slash)	Block skip function symbol or division in Fanuc macros
()	Parenthesis	Program comments & messages
%	Percent sign	Stop code (end of program file)
:	Colon	Program number designation
,	Comma	Used only within comments
[ ]	Brackets	Arguments in Fanuc macros
;	Semicolon	Non programmable End-of-Block symbol (screen display only)
#	Sharp sign	Variable definition or call in Fanuc macros
=	Equal sign	Equality in Fanuc macros

Lesson-4: Address Characters:

Address Characters:

Alphabet	Meaning / Used in
A	Angle
F	Feed function( mm/revolution)
N	Sequence number / block number
O	Program number/address
R	Radius
S	Speed in RPM (revolution/minute)
T	Tool number
U	Incremental in X axis
W	Incremental in Z axis
P, U, X	Designation of dwell time
G	Preparatory function - Specifies a motion mode (Linear, arc, etc)
M	Auxiliary function -Command of on/off for operating parts of machine
L	Sub program repetition count

Lesson-3 : CNC Turning - Axis Nomenclature

Number of axes:

            The most common distinction of different CNC lathes is by the number of programmable axes. A typical CNC lathes have two standard axes – one axis is the ‘X’ axis, other axis is the ‘Z’ axis. The X-axis also represents the cross travel of the cutting tool, the Z-axis represents its longitudinal motion.

                        X – Diameter

                        Z – Length

Lesson-2 : Incremental method

2) Incremental Method
         In Incremental method we must calculate values from the previous point.
Assume that we are calculating values in counter clock wise direction. so for point 2 we take point 1 as a ref. point. for point 3 we take point 2 as a ref. point.

Lesson-1 : Fanuc control- Absolute method

Now we are going to see Fanuc control programming for CNC Turning machines.

There are two methods we can use for writing a CNC program.
1) Absolute Method 2) Incremental Method.

1) Absolute Method

      In Absolute method we should calculate values from the reference point.

About CNC Machines

Dear friends,

   " பல்லவை கற்றும் பயமிலரே நல்லவையுள்
நன்கு செலச்சொல்லா தார்"

                                               - திருவள்ளுவர்

    " Though many things they've learned, yet useless are they all,
To man who cannot well and strongly speak in council hall"

                                                 

                                                - Thiruvalluvar

      CNC is the short form of Computer Numerical Control. In CNC Machines a mini computer controls the machine using numbers and codes.In 1950 JOHN T.Parsons and Frank L.Stulen developed CNC machines with their team.After many developments now we have advanced CNC machines in all the industries.

      There are so many types of CNC machines. In that CNC Turning and Milling machines are mostly used in Automobile industries.

      Types of CNC Machines:

      CNC Turning (Lathe/VTL)

      CNC Milling (VMC/HMC)

      CNC Wirecut

      CNC Grinding

      CNC Laser Cutting

      CNC Plasma Cutting

      CNC Routers

      CNC Drilling and Tapping

      CNC winding 

      etc...

      Types of Controls:

      Fanuc

      Siemens

      Mazatrol (Mazak)

      Mitsubishi

      Hurco

      Heidenhein

      etc...