Originally Posted by PoiToi  why would the spindle have to be stopped before the M29?? |
Watch a machine with rigid tapping.
Before the cycle starts the spindle will rotate alittle to find the index mark on the spindle encoder.
If the spindle is on allready on, it will stop, find its mark then do the tap cycle.
This has been aboserved on Fanuc 16Mi, 18MB and Haas machines.
In fact it notes in the Haas programming manual that if the rigid tap option is enabled it is used by default (no M code required just a G84) and that your best off not starting the spindle after the M6 because the machine will execute a M5 before starting a G84.