Fixed cycle (Back spot facing)

Q: What does Mazak G-code G77 do?

G77 — Fixed cycle (Back spot facing) on the MAZATROL SmoothX control (INTEGREX e-670H). Normally, asynchronous feed (G94) is used for the pass marked with (). If f = 0, or if f is omitted, however, synchronous feed (G95) is used (feed rate = 0.5 mm/rev). X, Y, P, Q, E, J (B), and/or D can be omitted. Whether argument J or B is to be used depends on the value that has been set in bit 1 of Parameter F84 bit 1 = 1: Argument J-command (argument J-command), setting a B-command will cause the table to rotate. Be careful in that case to ensure no interference between the workpiece and the tool. In G91 (incremental data input) mode, the direction of hole machining is automatically determined according to the sign of Z data (the sign of data at address R will be ignored). X, Y, P, D, K, and/or Q can be omitted.

Q: What is the programming format of G77?

G77 [Xx Yy] Rr Zz [Pt Qt ] Ff [Ef Jj (Bb ) Dd ]

Machine-specific. This G-code reference is specific to the Mazak INTEGREX e-670H / e-670H-S with the MAZATROL SmoothX control (EIA/ISO programming manual H747PB0030E). G-code availability depends on fitted options, and groups and behaviour differ between Mazak models and control generations — verify against the manual for your own machine before programming with any code.

What it does

Normally, asynchronous feed (G94) is used for the pass marked with (). If f = 0, or if f is omitted, however, synchronous feed (G95) is used (feed rate = 0.5 mm/rev). X, Y, P, Q, E, J (B), and/or D can be omitted. Whether argument J or B is to be used depends on the value that has been set in bit 1 of Parameter F84 bit 1 = 1: Argument J-command (argument J-command), setting a B-command will cause the table to rotate. Be careful in that case to ensure no interference between the workpiece and the tool. In G91 (incremental data input) mode, the direction of hole machining is automatically determined according to the sign of Z data (the sign of data at address R will be ignored). X, Y, P, D, K, and/or Q can be omitted.

G77 is modal (group 09) — it stays in effect until another code of the same group replaces it.

Programming format

G77 [Xx Yy] Rr Zz [Pt Qt ] Ff [Ef Jj (Bb ) Dd ]

Address words

t c : Dwell (in time or No. of revolutions) j 0 (b 0 ) : Output order of M03 and M04 at hole bottom.
t z : Distance from the initial point 0: M03, then M04 (for normal spindle rotation)
f 0 : Feed rate 0 1: M04, then M03 (for reverse spindle rotation)
f 1 : Feed rate 1 d 0 : Distance from point R’
Note: For a horizontal machining center, if the value of bit 1 of parameter F84 is 1
t c : Dwell (in time or No. of revolutions) k 0 : Distance from point Z
d : Distance from R-point i : Distance from point Z

Notes & precautions

For a horizontal machining center, if the value of bit 1 of parameter F84 is 1

Source

Mazak PROGRAMMING MANUAL for EIA/ISO PROGRAM, manual H747PB0030E, section 13-1-9 G77 [Back spot facing], p. 3-11, 13-12, 13-13. Reference and explanation only — not a reproduction of the manual.

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