Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 569)

Compound Turning Routines
Chapter 24
24-5
Where : Is :
I K determine the amount of stock to be removed on the final pass of the routine. The
actual amount of material removed on this final pass is equal to the average of the I
and K parameters ((I+K)/2). It is not necessary to enter both of these parameters in
the calling block. If only one is entered the control uses half of the entered
parameter value. The final pass is optional and does not need to be programmed. It
is not a roughing pass and it does not remove the finish allowance. A final pass cuts
tool paths that are parallel to the workpiece finish shape.
Important: This manual makes the assumption that I and K are assigned in
AMP as the integrand axis names that correspond to the X and Z axes respectively.
Important: The value assigned to I and K are always incremental, radius
values regardless of the current mode (radius/diameter or incremental/absolute).
Important: The system installer has the option of forcing a final pass to be
made by setting the proper AMP parameter. If this is the case, the control cuts the
final pass regardless of whether I or K is programmed. When I and K are not
programmed and the system installer has forced a final pass to be made, the control
assumes I and K to be zero.
D__
the depth of cut for each pass except the final pass. No sign needs to be entered for
this parameter. The depth of cut for the final pass is determined with the I and K
parameters. D is always an incremental value regardless of the current mode.
Important: It is possible to override the programmed depth of cut (D) using an
AMP parameter. The override setting is made in increments of 1% ranging from 0 -
255%. See documentation prepared by the system installer for details. The system
installer may also determine a maximum allowable value of D in AMP. If D is
programmed larger than the AMP threshold for D, the control overrides the
programmed depth and use the AMP assigned maximum depth.
R__ used to program the retract amount made after each roughing pass. This retract
amount is an incremental, radius value measured parallel to the X axis. Case 1
operations retract at a 45 degree angle to the X axis and Case 2 operations retract
parallel to the X axis. This does not affect the programmed value of R, as R is
always measured parallel to X. If no value for R is programmed then the control
uses the value for the retract amount set in AMP by the system installer.
F__ Active feedrate during the routine only (see chapter 17)
S__ Spindle speed during the routine only (see chapter 16)
T__ Tool number and tool offset to be used during the routine only (see chapter 19)
Important: Any F-, S-, or T-words that are in the set of contour blocks are
ignored when the routine is executed. If programmed in the G73 block these words
replace any previously active modal F-, S- or T-words for the remainder of the G73
routine operation only. When the G73 routine is completed the previously active
modal F-, S-, and T-words are reactivated.