Printed from Kezuriba (kezuriba.net/en/nc/g68/)

G68

Machining center, LatheModal, group 16

Coordinate rotation

⌨On machining centers

G17 G68 X_ Y_ (rotation center) R_ (angle)

Often an optional feature
R is positive counterclockwise (Haas). If the rotation center is omitted, the current position is the center (Haas)
Apply cutter compensation after the rotation, and cancel it before cancelling the rotation (Haas)
When combined with scaling, enter G51 then G68 in separate blocks in that order, and cancel in the order G69 then G50 (Haas)

Diagram: Coordinate rotation: center and angle

G68 X_ Y_ R_ rotates the coordinate system by R degrees about (X, Y), and the following commands are cut in the rotated orientation. R is positive counterclockwise. Cancel with G69.

◎On lathes: Meaning differs by machine (see variants below)

The same number means something different on lathes (FANUC-type G-code system A).

≠Differences between controls and machines

The same code can be written or assigned differently depending on the CNC control and the machine builder. Always check your machine’s manual.

Source	Machine	Item	Detail
Siemens (ISO dialect)	Lathe	Meaning	Opposed turret (dual turret) mirror ON (group 4)In the Siemens ISO T table, G68/G69 are dual turret ON/OFF
Haas	Lathe	Meaning	Coordinate rotation (group 16)

📚Sources

The meaning shown agrees in at least two sources (agreement confirmed). Explanations are written in our own words.

Siemens AG — SINUMERIK 802D sl/840D/840D sl/840Di/840Di sl/810D Programming Manual ISO Milling, 04.2007 Edition (6FC5398-7BP10-0BA0) cache.industry.siemens.com
Haas Automation, Inc. — G-code, M-code, and Setting (per-code explanation pages) haascnc.com
Haas Automation, Inc. — Mill Operator's Manual – 17 Mill G-Codes (online version) haascnc.com
Siemens AG — SINUMERIK 802D sl/840D/840D sl/840Di/840Di sl/810D Programming Manual ISO Turning, 04.2007 Edition cache.industry.siemens.com
Haas Automation, Inc. — Lathe Operator's Manual – 16 Lathe G-Codes (online version) haascnc.com