Owner's manual

Using Post Milling Cycles
Chapter 23
23-2
Use the G88.3 post milling roughing cycle to rough out a rectangular post
in a workpiece. This cycle makes multiple cuts at a programmed width
and depth.
The G88.3 block used to rough out a rectangular post has this format:
G88.3 X__Y__Z__I__J__Q__(,R or,C)__P__H__D__L__E__F__;
Where : Is :
XY
The coordinates thatspecify the centeroftherectangularpost.
Z
The coordinate (along the plungingaxis)thatspecifies the bottomofthe rectangularpocket. In
incremental mode this parameter specifies the depth ofthe pocketasmeasured fromthe startlevel
to the pocketbottom. Thisparametermustbe programmed.
IJ
The length ofthepost’ssides. Ispecifies the length oftheside paralleltotheXaxis. J specifies
the length ofthe sideparallel to the Yaxis. These are unsignedincremental values.
Important: Itisassumedthat Iand Jareassigned in AMP as the integrandaxisnamesthat
correspond totheX andYaxes respectively.
Q
Unsignedincremental valuethatspecifies the distance fromthe sides ofthe postto the outer
perimeterofthe pocket. This distanceisthesamewhethermeasuredalong the Xorthe Yaxis.
,R
Corner radius. This isan optionalparameterthatis used to programroundedinteriorcorners inthe
rectangularpocket.
,C
Corner chamfer. This is anoptionalparameterthatis used to programchamferedinteriorcorners
intherectangularpocket.
Important: In ordertoprogramrounded or chamfered cornerstheChamfering and Corner
Radiusoption mustbe installedin the control.
P
Directionofroughing cut. Thisparameterdetermines whethertheroughingcutsare performed ina
clockwise orcounter-clockwise motion. P0 specifiesclockwise. P1 specifiescounter-clockwise.
Important: Ifcuttercompensation(G41/G42)was enabled priortotheG88.3block,itis
disabledwhen G88.3is enabled.
H
The finishallowancethatwill be lefton the sidesofthe post. Thisfinish allowance canbe removed
laterusing a G88.4finishing cycle.
To leavea finishallowance on the pocketbottom,programapocketdepth(Zparameter)thatisat
the desired finish allowanceabove the actual pocketbottom. This finishallowancecan be removed
laterusing a G88.4finishing cycle.
D
Roughingcutthickness. This parameter specifies the maximumwidth ofanyXYaxisroughing
cuts. Thisisan optional parameter. Ifnot programmed,the controlusesthedefaultthickness,
whichisequal to halfofthe current tooldiameter.
Important: T he roughing cutthicknesscan notbegreaterthanthediameterofthecurrent
tool. Ifitis,the controlenters Cycle-Stop mode and displaysthe errormessage“D-WORD
LARGER THAN TOOL DIAMETER”on the CRT.
L
Incrementalplunge depth ofeachcuttingpass along the Z axis. Thisisan optional parameter. If
notprogrammed,theplunge amountwillbe equalto the programmed depth ofthe pocket.
E
Plungefeedrate. ThisparameterdeterminesthefeedrateofanyZ axismoves. If notprogrammed
the roughing feedrate(F)will beused.
F
Roughingfeedrate. This parameterdeterminesthefeedrateofany XYaxis moves. Ifnot
programmed the existing(modal) feedrate will beused.
23.1.1
Rectangular Post Roughing
Using G88.3