Hi John
For now ignore the green box you have drawn, they look to be a connection to the FWD/REV bulbs in those 2 switches on the control panel (most likely 2 thin wires going from rl3).

The spindle speed is reliant on a 0 - 10v signal coming from whatever control board you will use.

FWD /REV will also be dependant on the controller you use, at switch on Relay3 will switch to one position, this will be either Forward or Reverse. Lets for the sake of argument we'll call it default position.


You will need to copy the circuit with additional relays.

Most s / controllers have a relay on board for fwd reverse if so, there will normally be a nc / no and com connection.
So you would connect the com(mon) to 0v from pwr supply.
NC(normally closed or for the sake of quickness On as it is directly connected to the com terminal). would go to one ov side of Rl3
NO(normally open or for the sake of quickness Off as it is only connected to the com terminal when selected and at the same time Nc will disengage). would go to Tudder ov side of Rl3.
Sorry if it's too simplistic as i don't know your comfort level with electrics.

Now if you look at the diagram you posted you will see that one live terminal is also relay driven from RL1 , This is a safety relay to ensure lenze board powers up after the pc connection is made, However as you will be using your own electrics simply connect the new relay (make sure it is a mains spec relay as it will be switching the live supply to the lenze controller) and needs a dc coil ,connect the coil via the on off switch ,so the spindle only has power when that switch is on.

You can add another change over relay to the spindle drive in between rl3 and your bob relay, will attach a diagram for that option based on the circuit diagram but bear in mind you wont be using the boxford board so these relays will need to be sourced. (PM your address and i will pop an omron my4 relay and holder in the post to you, will be the end of next week though).

I also switch the mains through a relay via the E Stop switch as mine has 2 micro switches on it one nc and one no
Do one bit at at a time