retrofit Boxford vmc mill 260 Info needed on Yaskawa contactor relay and VFD choices

[JAZZCNC]

Ok well please don't think I'm being OFF or clever with you but getting the terms correct is very important when trying to help.

Regards the Spindle then you need either a BOB with analog or PWM 0-10v speed control OUTPUT built into it. Or a separate Analog 0-10v speed control that uses an Axis Output like DIYCNC SpindleV4 board. The term VFD refers to Variable frequency drive and is differant animal.

The Gemini is converting AC into DC and doing the controlling so you just need to feed it a reference voltage for the speed, eithier thru Analog 0-10v control or manual Rotary Pot.(potentiometer)
Yaskawa Contactor is just a switch in affect controlled with a lower voltage from another source, most likely an output from the motion control board or BOB which again will most likely control a 24v source which turns the contactor ON/OFF.?