Please see the attached images. I want to be able to unfold this part so it is parallel with the horizontal plane. The default result is as shown in Image 1; pivoting from one end so the flat pattern is on an incline. I want it to flatten from the central point symmetric about the vertical plane as per Image 2.
Is there a way of modelling this so that the flatten or unfold results display as I want?
I'm unclear as to why you would want to do that but I'm sure you have your reasons. The only thing I can think of would be to add a small flat area in the middle of you arc.
Or don't put the flat in and do a Move/Copy Bodies on the flat pattern in order to align the flat pattern to your planes.