Hi Jim,
This is sort of what @jeff_hammond Jeff indicated.
Split the original polysurface with the wires in question;
Offset the split polysurface strip, with solid option, to the req’d depth;
Boolean doesn’t seem work in this case so;
Explode original shape (in this case);
Extract and delete outer surfaces of the strip to form channel;
Rejoin all the surfaces;
If looking for other than rectangular groove, adjust to suit.
Use the same method for the other crossing grooves.
