Details
There is no "Gap" option in NX Sheet Metal "Three Bend Corner" operation.
Solution
Workaround:
Unbend the sheet metal part
Offset (by half of the gap required) the edges of the cut.
Create a sketch using the offsets and create a 'Normal Cutout'
Rebend the bends to view the sheet metal part .
Notes and References
ER 8437690
Hardware/Software Configuration
Platform: INTL64
OS: windows
OS Version: 1064
Product: NX
Application: NX_SHEET_METAL
Version: V1888
Function: 3_BEND_CORNER
Ref: 001-8437690