hello again, please check attached image
long story short : sync zy
the time required for real trials on that multus-u4000 is much shorter than the time that i need to fully understand this kind of process and develop sharp code
if the hob is spinned directly by M axis ( like and end-mill ) , i recomand using the hob in the area near the tool shank, for better cutting rigidity
when wear appears, simply move towards the top ( maybe also reduce cutting specs ), so a fresh row of teeth will be delivering the finished surface
i may be wrong, since flipping the tool requires reversed sense of the M axis, and it may possible that a new tool could not be used towards the shank, but only towards the top, so a bit of rigidity will be lost, but it may be just fine; kindly