This may help the next person as this thread is over a year old. I use SketchUp regularly and you may be looking for a plug-in called 'Unfold'. If you were to create a 3d box, the tool will pancake the box 'open' on the floor of the workspace. You could then print this out on paper, and trace onto your sheet metal and follow the cut & bend lines to create your original Box. This doesn't seem impressive but imagine using it on a multi angled bracket with several holes and flanges.
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Vinny
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