Retrofitting HURCO BMC30

Thank you for the quick replay as always!

Yes that is maybe a little overkill.

When having a further look at it a 7i92tm directly connected to a 7i77 (EUSurplus did have this in stock), a 7i74 and 7i70 and 7i71 for IO:s would also work fine as I can understand it and it will be a little cheaper as well

Is in the works of finishing the electrical drawings of the BMC30 update.

But i would want to preserve some of the safety features.

In the current configuration a lot of the outputs are fed 24V through a relay and I would like to still have it like this.
But reading the manuals for the 7i77 and 7i71 the cards should not be provided VFIELD through a relay.

What is the danger to add a relay in the VFIELD is it the risk of contact bouncing when enabled or that the power could switch rapidly? 
Would it be acceptable to provide power through a safety relay that needs to be reset to be enabled again? (Then rapid on/off switching will not be that rapid)

Update:
Solved it by having the actuators over the same ground which a relay switches instead.

Question, do anybody know the gear ratio between the screws and servos on a machine with Siemens servos?
The servos are 1ft5 Servos and the pitch of the screws seems to be 12 mm what i could measure with calipers.