HEIDENHAIN TNC 407 (243 020) Technical Manual User Manual
Page 239
If the tapping cycle is called, marker M2048 is set by the NC.
After switching on the spindle with M03 and successful acknowledgement (marker M2482) the set
spindle-speed should have been reached when the feed commences. Upon switch-on, the spindle
follows the ramp from MP3410.0, on switching off it follows the ramp from MP3410.2. Switch-off is
initiated by the NC with M05. The M functions that are output must be acknowledged.
However, if the feed-ramp is flatter than the spindle-ramp, then the spindle follows the flatter feed-
ramp. Switch-off can be delayed by MP7120.2.
Example:
If spindle speed s = 1000 [rpm] = 1.8 [V] and the thread ramp is 0.05 [V/ms], then:
1.8 [V]: 0.05 [V/ms] = 36 ms
The spindle is decelerated 36 ms before reaching the total hole depth. If the spindle deceleration is
delayed by the spindle slow-down time, then it is only possible to delay up to 30 ms before reaching
the total hole depth. Any greater delay will be ignored. In this example a maximum slow-down time
of 6 ms is in effect.
The restarting of the Spindle with M04 can be delayed by MP7120.0. The ramp follows MP3410.2
again. The restarting of the feed can be delayed with the dwell-time which is programmed in the
cycle. The dwell-times permit an optimal adjustment of the floating tap holder.
The switch-off of the spindle is again performed by the NC with M05. The switch-off ramp follows
MP3410.0. After this, the spindle is switched on again with M03.
The feed-override can only be effective within limits when tapping, otherwise the floating tap holder
may be damaged. MP7110 was introduced for this limit.
MP3410.2 Ramp slope of the spindle for tapping
Entry: 0.0000 to 1.9999 (V/ms)
MP7120.0 Dwell-time for change of direction of spindle rotation
Entry: 0.0000 to 65.535 (s)
MP 7120.2 Spindle run-on time after reaching total hole depth
Entry: 0.0000 to 65.535 (s)
MP7110.0 Minimum for feed-override when tapping
Entry: 0 to 150 [%]
MP7110.1 Maximum for feed-override when tapping
Entry: 0 to 150 [%]
Marker
Function
Set
Reset
M2048
Tapping cycle called
NC
NC