“Earthing” of a controller box of CNC machine in TN-C (TN-C-S) system of supply 230 V

Hello guys,
My name is Hristo, I am from Plovdiv, Bulgaria. I have tried to make my first hobby cnc machine,
but my experience of electronics is very small.
I have a question about “Earthing”. I have to note before, that our building is old, and there are only 2
conductors, and we have not separate conductor for “Earthing” unfortunately. This systems are TN-C
and TN-C-S. In this case, we have to use “neutral” for this kind of “Earthing”.
The main elements of electronic are: Arduino Uno; 3 steppers-NEMA 24- 3,1 N.m; 3 stepper-drivers-
SH-750- 5A, PSU-s - one 36V DC for steppers, and other - 12V DC for fans, (5V for Arduino from
computer‘s USB).
I will not use a VFD for motor-spindle. I have intention to use routing motor-spindle, and I will
connect it directly to 230 V- AC, and will be no connection to controller.
I will “Earthing” 2 PSU by “neutral” in “star” point (in TN-C-S system), but I am afraid to connect in
this “star” point stepper drivers (GND) and Arduino (GND). I think, that it will be too risky.
It is possible to put any rod for local “Earthing” (something like TT-system), but this is not very easy
task.
What do you think about this situation ?
Best regards
Hristo