HEIDENHAIN TNC 335 Technical Manual - Manual (Page 197)

4-100
TNC 360 4 Spindle 8/95
If the tapping cycle is called, marker M2048 is set by the NC.
After switching on the spindle with M03 and successful acknowledgment (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. The M
functions that are output by the NC 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], the thread ramp is 0.05 [V/ms], and the feed ramp is
steeper than 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. The spindle deceleration can
be delayed by the spindle slow-down time.
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 for tapping
Input value: 0 to 1.999 [V/ms]
MP7120.0 Dwell time for change of direction of spindle rotation
Input value: 0 to 65.535 [s]
MP7120.2 Spindle run-on time after reaching total hole depth
Input value: 0 to 65.535 [s]
MP7110.0 Minimum for feed override when tapping
Input value: 0 to 150 [%]
MP7110.1 Maximum for feed override when tapping
Input value: 0 to 150 [%]
Set Reset
M2048 Tapping cycle called NC NC