
B–63833EN–1/02
9. SPINDLE SPEED FUNCTION
525
In a tapping cycle (M series: G84/G74, T series: G84/G88), 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 9.10.2)
· Addition of a sequence to the PMC (described in 9.10.6 and 9.10.7)
· Setting of related parameters (described in 9.10.8)
This section provides an example of M series connection.
To avoid duplicate descriptions, assume the following unless noted
otherwise:
⋅ G code for a tapping cycle
M series: G84 (G74) T series: G84 (G88)
⋅ Gear selection method
M series: M–type or T–type gear selection method
T series: T–type gear selection method only
⋅ Parameters used according to the number of gear stages (No. 5221
to No. 5224, No. 5231 to No. 5234, No. 5241 to No. 5244, No.
5261 to No. 5264, No. 5271 to No. 5274, No. 5281 to No. 5284,
No. 5291 to 5294, No. 5321 to No. 5324, etc.)
⋅ M series: Up to three stages T series: Up to four stages (The stages
are also used for the second spindle, and up to two stages are used
with the second spindle.)
CAUTION
1 The description given in this section covers up to the second
axis.
2 When M–type gear selection is used for the M series, 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.)
9.10
RIGID TAPPING
9.10.1
General