Owner's manual

Using Hemisphere Milling Cycles
Chapter 24
24-2
Use the G88.5 concave milling roughing cycle to rough out a concave
pocket i n a workpiece. This cycle makes multiple concentric circular cuts
at a programmed width and depth.
The G88.5 block used to rough out a concave pocket has this format:
G88.5 X__Y__Z__R__Q0_P__H__D__L__E__F__;
Where : Is :
XY
The coordinates thatspecify the centeroftheconcavehemisphere inthe
selected plane.
Z
The coordinate (along the plungingaxis)thatspecifies the bottomofthe
hemisphericalpocket. In incremental mode this parameterspecifies the depth of
the pocketasmeasured fromthe startlevelto the pocketbottom. This
parametermustbe programmed.
R
Radiusofthe concavehemisphere.
Q0
Codespecifying aconcavehemisphere.
P
Directionofroughing cut. Thisparameterdetermines whethertheroughingcuts
areperformed ina clockwiseor counter-clockwise motion. P0specifies
clockwise. P1 specifiescounter-clockwise.
Important: Ifcuttercompensation(G41/G42)was enabled priortothe
G88.5 block,it is disabled whenG88.5isenabled.
H
The finishallowancethatwill be lefton the sidesofthe concavehemisphere.
This finishallo wance can be removed laterusin g a G88.6 finishing cycle.
D
Roughingcutthickness. This parameter specifies the maximumwidth ofanyXY
axisroughingcuts. Thisisan optional parameter. Ifnotprogrammed,thecontrol
usesthedefaultthickness,whichis equalto halfofthe currenttool diameter.
Important: T he roughing cutthicknesscan notbegreaterthanthediameter
ofthe currenttool. Ifitis,the controlenters Cycle-Stopmodeand displays the
errormessage“D-WORDLARGER THAN TOOL DIAMET ER”on the CRT.
L
Roughingcusp height. This value ofthis parameteris ameasurementthat
correspondstotheheightofthe materialleftalong thesides of thehemisphere
aftereachX-Zroughingplunge.
E
Plungefeedrate. ThisparameterdeterminesthefeedrateofanyZ axismoves. If
notprogrammed the roughing feedrate (F)will beused.
F
Roughingfeedrate. This parameterdeterminesthefeedrateofany XYaxis
moves. Ifnotprogrammedtheexisting (modal)feedrate will beused.
If Q0 is programmed, the control generates a concave hemisphere. The
control m akes multiple concentric circular cuts at each level of the concave
hemisphere. The depth of the pocket increases and the diameter of each
level decreases until the bottom center of the concave hemisphere is
reached.
24.1.1
Concave Hemisphere
Roughing Using G88.5