7. FLOATING REFERENCE POSITION
FLOATING REFERENCE POSITION RETURN (G30.1)
Tools ca be returned to the floating reference position.
A floating reference point is a position on a machine tool, and serves as
a reference point for machine tool operation.
A floating reference point need not always be fixed, but can be moved as
Command of the intermediate position of the floating reference
(Absolute command/incremental command)
Generally speaking, on a machining center or milling machine, cutting
tools can be replaced only at specific positions. A position where tools can
be replaced is defined as the second or third reference point. Using G30
can easily move the cutting tools back to these points. On some machine
tools, the cutting tools can be replaced at any position unless they interfere
with the workpiece.
With these machines, the cutting tools should be replaced at a position as
close to the workpiece as possible so as to minimize the machine cycle
time. For this purpose, the tool change position is to be changed,
depending on the figure of the workpiece. This operation can easily be
performed using this function. That is, a tool change position suitable for
the workpiece is memorized as a floating reference point. Then command
G30. 1 can easily cause return to the tool change position.
A floating reference point becomes a machine coordinate position
memorized by pressing the soft key
[SET FRP] on the current positions
display screen (see III–11.1.7). The G30.1 block first positions the tool
at the intermediate point along the specified axes at rapid traverse rate,
then further moves the tool from the intermediate point to the floating
reference point at rapid traverse rate.
Before using G30.1, cancel cutter compensation and tool length
A floating reference point is not lost even if power is turned off.
The function for returning from the reference position (G29) can be used
for moving the tool from the floating reference position (see II–6).