Sheet metal join problem

[AJ_12152667]

I have a problem with a part that looks like that while unbend:

And that as bend:

The problem starts with those small internal surfaces in the cutouts. They must remain flat.

I have tried to use JOIN but I have an issue with it. There is an error. I'll explain in another reply or edit this on later.

For the moment the question is, can I "split" bending line to not bend those small features? 

[tbraxton]

One way to get this in sheetmetal mode.

[pausob · Accepted solution]

You can use the separate surface region function to split the bend and then you will be able to un-bend the tabs only:

1) start here:

2)  Split the bend surface where the tab(s) are:

--> 

3) Unbend the tabs only:

-->

End result: