Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 390)

Axis Motion
Chapter 14
14-14
Determining Rotary axis feedrates
The feedrate for a rotary axis is determined in much the same way as linear
axes.
When the control is in rapid mode (G00) the feedrate for the rotary axis is
the rapid feedrate for that axis as set in AMP. Remember that if other axes
are moving in the same block the feedrate for the block is limited by the
axis which will take the longest time to complete its programmed move at
its rapid speed (see chapter 18 for details).
When the control is in one of the cutting modes (G01, G02, or G03) the
control uses the programmed feedrate to calculate the angular velocity of
the rotary axis. This feedrate is still limited to the maximum cutting
feedrate (feedrate clamp) as determined in AMP.
When programming in G95 feed per revolution mode the rotary axis will
perform the required amount of angular rotation for every revolution of the
spindle. If programmed with other axis motions in G93 or G94 modes.
The resulting feedrate for the block is applied to the total distance to move
the axes including the rotary axis
In any event if a rotary axis is programmed in a block with other axis
moves in either rapid (G00) or cutting (G01, G02, or G03) modes, all axes
will reach their destinations at the same instant.
CAUTION: Keep in mind when programming a rotary axis that
the programmed feedrate is in units of angular velocity. This
means that the actual cutting feedrate will be dependant on the
tool’s distance from the center of rotation of the rotary axis.
The cylindrical interpolation feature coordinates the motion of a rotary axis
with the linear machine axes to machine contours on the side of a
cylindrical workpiece as shown in Figure 14.9. Cylindrical interpolation
mode is turned on using a G16.1 block and turned off with a G15 block.
A mill control with a minimum of two linear and one rotary axes is
required for cylindrical interpolation. Typically there will be three linear
and one rotary axis.
Cylindrical interpolation requires that axes be defined in AMP as a
cylindrical interpolation rotary axis, a linear axis, a park axis, and a feed
axis. The coordinates of the park and feed axes that define the rotary axis
center-line must also be specified. Refer to the information provided by
your system installer.
14.1.6
Cylindrical Interpolation