post 101 - the green box is a mains powered load switched on & off by the relay

in the diagram its shown as a pump but in your case it can be the speed control for the spindle motor


post 102

if its the 12V supply shown on this diagram

Attachment 435552

then yes


photos of the boards you are now using in your machine will be useful and the manufactures part numbers

so I can double check what you have now



John