Tube mitre development?

So far I have achieved this by:

modelling my mitred tube using trim surfaces in an asm taking out a tiny sliver along its length to enable; unbending it in sheetmetal produce drawing

Any quicker suggestions/functionality?

Do I need to 'split' the tube or can I use a closed tube in sheetmetal and define where the split is? Looks unlikely because there will be no edge/plane to select as the fixed geometry.

Cheers, Sean

Layout with descriptive geometry, the way you'd describe a tabulated surface for bending duct work and filing the mitre. In the left view, draw a rectangle the height of your tube with a width of pi*D. On the right, draw a circle the diameter of your tube, aligning the top edge of the circle with the top edge of the rectangle. The draw a line on the rectangle marking the bottom edge of the circle. Divide the rectangle and circle into the same number of equally spaced parts. Draw horizontal lines from the circle divisions to the vertical section marks on the rectangle. For each set of points on th circle mark a left and right section mark, working from the outside in. Put points on the intersection of the vertical and horizontal marks. With enough points, you can make a pretty smooth curve for your filing template.

David Janes

You're nearly there. Instead of a tube with a tiny aplit use a semicircle with a tangential flat to use as the base for flattening, this gives you half of what you want, the rest can be done in an assembly. Incidentally, the pick for the flattening says that a plane can be picked and then does not allow it, hence the piece of flat.