Hi everyone...

I’m facing a major problem that I can't seem to solve, and I haven't found anything online to help me fix it...

I’m trying to create the sheet metal enclosure for an elliptical staircase; I modeled the stair flights and landings using single, continuous sheets. Now, my biggest issue is that I need to split these sheets... I’ve tried various methods to do this—using the cut tool (with the thin feature) or the split feature. Visually, the split looks perfect, but I need to flatten the parts... The problem is that I need to divide them into multiple sections; if I split a sheet into two parts, it flattens perfectly, but if I split it into three or more parts, it won't flatten anymore...

As seen in the figures above, I can easily flatten both parts...

But if I try to divide it into 3 or more parts, it no longer unfolds...

I can flatten the end pieces, but not the center one; this error appears...:

If I divide it into more parts, only the end pieces flatten out; the middle ones don't.

I’m sharing my drawing to see if anyone has any ideas on how to solve this. The only option I have right now is to do it section by section to get isolated parts, but that’s not practical at all. I can’t believe there isn’t a solution for this; I must be missing a step to be able to flatten these parts...

Thank you all very much.