Thanks. I see it all clearer now.

I see that rotating the T/C plane is suggested. My question is, why choosing system veiw 4[bottom] does not work. Let me try this again.....X pos. is to the left of 0 when I backplot.

I am as to why, for example, if I want to rotate my 4th axis 180 to work on the bottom side of a part, it only works if I rotate the T/C plane 180. If I choose system veiw 4[bottom] it looks good in backplot but if you look at the numbers, X- is +. Vertical Okuma, 4th axis is horiztontal, inline with X, on right side facing left.