The G70 finishing cycle is used on CNC lathes to perform a finishing pass on a part after roughing cycles like G71, G72, or G73. This cycle ensures that the final dimensions and surface finish of the part are achieved. Here’s a breakdown of the G70 cycle and an example program:

G70 Cycle Syntax

The G70 cycle typically consists of a single line of code:

G70 P(start line) Q(end line) F(feed rate);

• P: The starting block number of the subroutine.
• Q: The ending block number of the subroutine.

Example Program

Here’s an example of a G70 finishing cycle program:

N10 G71 U1.0 R1.0;          (Roughing cycle: 1.0mm depth of cut, 1.0mm retract)
N20 G71 P100 Q200 U0.2 W0.05 F0.2;  (Roughing cycle: start at N100, end at N200, 0.2mm finish allowance in X, 0.05mm in Z, 0.2mm/rev feed rate)

N100 G00 X19.0;             (Move to start position)
N110 G01 G42 Z0.0 F0.2;     (Linear feed, tool nose radius compensation on, move to front of part)
N120 X20.0 Z-0.5;           (Cut to X20.0, Z-0.5)
N130 Z-20.0;                (Move to Z-20.0)
N140 X40.0 Z-30.0;          (Cut to X40.0, Z-30.0)
N150 Z-65.0 R5.0;           (Move to Z-65.0 with 5.0mm radius)
N160 X60.0;                 (Cut to X60.0)
N200 G40 X70.0 Z5.0 F200;   (End of subroutine, tool nose radius compensation off, move to safe position)

N210 G70 P100 Q200;         (Finishing cycle: use the same path defined in the roughing cycle)

Explanation

• Roughing Cycle (N10 to N20): Defines the roughing passes with a depth of cut and retract amount.
• Subroutine (N100 to N200): Contains the profile of the part to be machined.
• Finishing Cycle (N210): Uses the same path defined in the roughing cycle (N100 to N200) to perform the finishing pass, ensuring the final dimensions and surface finish

G70 Cycle என்பது ஒரு finishing cycle இந்த cycle எழுத வேண்டும் என்றால் ஏற்கனவே நாம் ஒரு rough cycle இருக்க வேண்டும் ஏனென்றால் எந்த ஒரு Profile நாம் finish செய்யப்போகிறோம் என்று குறிப்பிடுவதற்கு நாம் G70 finishing cycle ல் கொடுக்கும் ஒரே option ஆனது starting block (N10)மற்றும் ending block(N20) F( Feed Rate)மட்டுமே

This example should help you understand how to use the G70 finishing cycle in your CNC programs. If you have any specific questions or need further details, feel free to ask!