the most difficult part of it is to control spindle (at least for me). I tought about putting there a separate PWM controller for spindle engine, and making a translater board for encoder signal.
Rest of it is just based on controling Z axis motnion and input signals drom proximity sensors. these signals are on the mainboard of EMCO control system so its quite easy except for a little detail- some of sensors works with 24V and other with 12V so there is a necessary to use some relays or transoptors for these signals.