Firstly I hope this is the right place for it.........
Right we have a Yang Eagle SMV1000 running Accramatic 2100 control.
When we run a fixed tapping cycle (G84.1) the machine will first index the spindle and tap the hole as per usual, then reverse the spindle and come back out the hole. When it reaches the clear plane it will rotate the spindle 360 deg one way quickly then very slowly rotale back to where it was (0 degrees)
We have looked at the encoder belt and fitted a new one thinking this could be the cause. Any other ideas?