Practiced with Longeron dies on some scrap angle that I got from the Yard. It seems like the dies are the way to go.

BUT- the instructions have you cut out the bend template from the bottom of drawing 17 or 17A, glue it to a backer, and bend the longerons to match. When I looked through my drawings, I discovered that there had been a printing catastrophe at Vans. Those two prints were printed wrong sized and all 4 sides were cropped off. No title block, no zone locators, and certainly no longeron template along the bottom.

I called Vans and Gary in builder support told me that those two prints were supposed to be printed on larger sheets so that he longeron templates ended up actual size. In my case, they got printed the same size as everything else which obviously won't work.

They are going to send me correct sized copies of those two prints, but there's not really a good way to bend the longeron until that happens, so I'll move on to something else after the weekend.