Let the fun begin !!! ???

[JAZZCNC]

Ok well think things could all change now if you wanted because I'm pretty sure that Bob can handle 24v thru it's inputs.? The manual certainly shows them using 12V.

So in this case you could remove the Relays and run 24V thru the Limit switches wired in series just the same but directly to the BOB Limit inputs. I think you'd still need an Over ride button as the Inputs are driving the Enable output so Mach's Auto limit override won't turn these back on.
Then connect the Enables on the BOB to the Enables on drives.

Or just go with my first suggestion if you prefer and want to play safe regards what the Inputs can handle.!

New pic.

Edit: Yes those inputs have 30V Max so your good to go with this Pic.