Fixed cycle (Reverse tapping)

Q: What does Mazak G-code G74 do?

G74 — Fixed cycle (Reverse tapping) on the MAZATROL SmoothX control (INTEGREX e-670H). c the return speed override (%) for synchronous (b ) 2...M03 before dwell at hole bottom 0 X, Y, P, J(B), D, H, and/or K can be omitted. If, however, J(B) is omitted or set to 0, the setting of J(B) will be regarded as 2. If H is omitted, synchronous tapping method is automatically selected.  For synchronous tapping, see Subsection 13-1-21. 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 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. (Direction determined by bits 3 & 4 of I14) k : Distance from point Z X, Y, P, Q, D, J(B), K, and/or I can be omitted. Whether argument J or B is to be used depends on the value that has

Q: What is the programming format of G74?

G74 [Xx Yy] Rr Zz [Pt ] Ff [Jj (Bb ) Dd Hh Kk ]

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

c the return speed override (%) for synchronous (b ) 2...M03 before dwell at hole bottom 0 X, Y, P, J(B), D, H, and/or K can be omitted. If, however, J(B) is omitted or set to 0, the setting of J(B) will be regarded as 2. If H is omitted, synchronous tapping method is automatically selected.  For synchronous tapping, see Subsection 13-1-21. 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 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. (Direction determined by bits 3 & 4 of I14) k : Distance from point Z X, Y, P, Q, D, J(B), K, and/or I 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 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.

G74 is modal (group 09) — it stays in effect until another code of the same group replaces it.

Programming format

G74 [Xx Yy] Rr Zz [Pt ] Ff [Jj (Bb ) Dd Hh Kk ]

Address words

t : Dwell (always in time) h 0 : Flag for synchronous/asynchronous tapping and
f 0 : Feed rate
j : 1...M03 after dwell at hole bottom
d 0 : Distance from R-point k 0 : Distance from R-point
Note: For a horizontal machining center, if the value of bit 1 of parameter F84 is 1 (argument
t c : Dwell (in time or No. of revolutions) j 0 : 0 or omitted ········· M03 after machining
q : Amount of relief on the XY-plane (b ) Value except 0 ····· M04 after machining
f 0 : Feed rate i 0 : Distance from point Z
d : Distance from R-point

Notes & precautions

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

Source

Mazak PROGRAMMING MANUAL for EIA/ISO PROGRAM, manual H747PB0030E, section 13-1-6 G74 [Reverse tapping], p. 3-11, 13-9, 13-10. Reference and explanation only — not a reproduction of the manual.

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