Manual

Spindles
Chapter 17
17-16
Where: Is:
R theradius at whichthe feedaxis (typicallythe X axis)is positionedat the start of
cylindrical interpolation. Can beused toalter thefeed axisdepth if programmedin a
G16.1 block during cylindricalinterpolation.
C theangular coordinate (if inG90 absolutemode) or theangular distance (if inG91
incremental mode) towhich the virtual Caxis isto move.
Z thecoordinate (if inG90 absolutemode) or thelinear distance (if inG91 incremental
mode) towhich theZ axisis tomove.
F thefeedrate tobe usedby thefeed axisto positionto radiusR, and usedby theZ axis
when commanded to move whileG16.1 isactive.
It also controls the virtualC axisspeed asthough it werea rotaryaxis. See chapter 18.
These parameters and their application are described in detail in the
paragraphs that follow:
The valued entered for the R parameter should place the tool at the radius
of the desired cutting depth into the part.
Important: R must be programmed in the initial G16.1 block. If R is not
programmed in the initial G16.1 block, the error message “CYLINDER
RADIUS IS ZERO” appears. At power turn-on, program-end (M02, M30,
or M99) or control reset, the virtual C axis feature is turned off and the R
value is set to zero. It must then be re-entered in the next G16.1 block.
The radius specified by the R parameter is modal and does not need to be
included in subsequent cylindrical interpolation blocks. Programming a
G16.1 block with a different R value modifies the feed depth to the new
radius. Feed depths cannot be changed using the X parameter when G16.1
is active. Programming an X generates the error message “FEED AXIS
MOTION NOT ALLOWED.”
Figure 17.3 illustrates the tool position if the AMP parameter Feed Axis
Park Location is selected as “Farthest from Machine Zero.” If “Nearest
to Machine Zero” were selected, then the tool would be positioned for
cutting into the part from the negative side of the X axis. Refer to the
information provided by your system installer.
A C or Z axis position may be programmed with the R parameter in the
initial G16.1 block. However, once G16.1 mode is established, only the Z
parameter can be programmed in the same block as the R parameter.
When it is, the Z axis motion executes first followed by feed axis motion to
radius R.
If a C axis position is programmed, the C axis rotates to the specified
angle. If the C and Z axes are programmed together in the same block,
then a vector motion results around the circumference of the part.