
B–63173EN–1/01
9. SPINDLE SPEED FUNCTION
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In a tapping cycle (G84/G74), synchronous control is applied to the
tapping operation of a tapping axis and the operation of the spindle.
This capability eliminates the need to use a tool such as a float tapper, thus
enabling higher–speed, higher–precision tapping.
Whether a tapping cycle is an ordinary tapping cycle or rigid tapping cycle
is determined by the miscellaneous function code for rigid tapping M29.
(A different M code can be used by setting the parameters accordingly, but
M29 is used in the description given here.)
By setting the parameters, G codes for tapping cycles can be changed to
G codes for rigid tapping only. In this case, the CNC specifies M29
internally.
To perform rigid tapping, the following must be added to the ordinary
connections:
· Connection of a position coder to the spindles (described in 9.5.2)
· Addition of a sequence to the PMC (described in 9.5.4 and 9.5.5)
· Setting of related parameters (described in 9.5.6)
CAUTION
When M–type gear selection is used, the maximum spindle
speed for rigid tapping (specified with parameters No. 5241
to 5243) must also be set for parameter No. 5243 regardless
of the number of gear steps. (For a system having a single
gear step, set the same value as that of parameter No. 5241
for parameter No. 5243. For a system having two gear
steps, set the same value as that of parameter No. 5242 for
parameter No. 5243.)
The descriptions given in this section (such as spindle gear switching and
M–type/T–type) are based on the explanation given in Section 9.3. Refer
to Section 9.3 as necessary.
9.5
RIGID TAPPING
9.5.1
General