For making channels I decided to cut all the flat sheet materials (blanks) to the correct width and length for each piece. Then I bend each one according the the Z-sheets and the appropriate drawings. I simply find it easier to do most of the cutting and drilling while the materials are flat, and then bending after the fact.
When I laid out all the blanks I laid out the longitudinal bend lines at the same time, so the bend lines were laid out consistently down the entire 12' of channels laid out on the flat aluminum sheets.
Since Kitlog only allows 3 photos per page, I've created some additional pages just to show the bending process.
