Bad metal sheet errors unfold
On your first approach of using the cut, turn off the Normal Cut option (Corte normal in your language in the video) and I believe you will get what you want. With this type of cut through the part, you don't want it to be a Normal Cut which is a specific type of cut for Sheet Metal.
See this help topic, and the 3 sub-topics referenced from it in the contents section to and in the table of contents on the left for more details and examples of what Normal Cut is used for:
2018 SOLIDWORKS Help - Normal Cuts
I hope this helps,
Hi Jim Wilkinson
that worked thank you very much
I had posted something earlier but was confused since I didn't see anything wrong with either file with either the Brida Base or the Pliegues recubiertos. Neither one has an issue as far as I can see with the cuts or flat pattern. In your second screenshot your part is hidden thus the empty flat pattern.
One more Edit:... Just can leave it alone please forgive me
Is this what you are attempting to achieved? Normal cut on the inside cylinder to match the loft?.
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