Manual

Compounding Turning Routines
Chapter 24
24-30
The G75 block is programmed with this format:
G75 P__ Q__ I__ K__ U__ W__ D__ F__ S__ T__;
Where : Is :
P__ Thesequence number of thefirst block inthe set of contour blocksthat defines the
finished workpiece shape.
Q__ Thesequence number of thelast block inthe set of contour blocksthat defines the
finished workpiece shape.
U W Finishallowance. These parametersdetermine thefinishing allowancethat is left on
the part when the routine is completed. This finish allowanceis typicallyremoved
later inthe program whena G72finishing routineblock isexecuted. The actualvalue
of the finish allowance is equal tothe averageof the Uand Wparameters ((U+W)/2).
It is not necessaryto enterboth of theseparameters inthe callingblock. If only one
is entered, thecontrol useshalf of the enteredparameter value as the finishamount.
The finish allowance is optional anddoes not needto beprogrammed. See
Figure 24.25 to determine thesign of U andW. U and W are alwaysprogrammed as
incremental values.
Important: This manualmakes theassumption that Wand Uare assignedin
AMP asthe incrementalaxis namesthat correspond tothe Zand Xaxes
respectively.
Important: The value assigned to U isaffectedby radius/diameter mode
(G08/G09). W is not affected byradius diameter mode. If programming in diameter
mode the value of the finishallowance isreally ((U/2)+W)/2.
I K Theseparameters determine the incremental distancebetween thefirst and last pass
of the routine. This distance is equal tothe averageof the I andK parameters
((I+K)/2). The locationof the last passis determined by the contour blocks and the
finish amount ((U+W)/2), if any is programmed. I and Kmust be programmed. They
are neither positive nor negative.
Important: This totalincremental distanceshould beless thanone toolradius if
cutter compensationis on when thiscycle isexecuted.
Important: This manualmakes theassumption that Kand I areassigned in
AMP asthe integrandaxis namesthat correspond tothe Zand Xaxes respectively.
Important: The values assigned toI and Kare always an incremental, radius
value regardless of the current mode(radius/diameter or absolute/incremental).
D__ Number of passes. The integer valueentered withthis parameterdetermines how
many passesare madeto reachthe final pass. The depth of each pass is
determined by dividing (I+K)/2by D-1. The valueentered with D must bean integer.
F__ Activefeedrate duringthe routineonly (seechapter 17)
S__ Spindlespeed duringthe routineonly (seechapter 16)
T__ Tool numberand tool offset tobe usedduring theroutine only (see chapter19)
Important: Any F-, S-, or T-words that are in the set of contour blocks are
ignored when the routine is executed. If these words are to be changed
from their current value, it is necessary to program an F-, S-, or T-word in
the G75 block. If programmed in the G75 block these words replace any
previously active modal F-, S-, or T-words for the remainder of G75
routine operation only. When the G75 routine is completed the previously
active modal F-, S-, and T-words are reactivated.