>>Am I overcomplicating this?<< Simple answer, No!
I've done two of these same tarps using the directions in Jay's article.
Read carefully Jay's introductory article Make Your Own Gear: Five Yards to SuperUltraLight
Part 1, Introduction in the same articles section.
>>The use of a catenary curve for the tarp left more fabric for the other smaller pieces in this project. I took advantage of this by extending the size of the foot-end overhang and increasing the width of the stuff sack and the pack’s side panel pocket<<
It has been my experience that there is a problem with the size of the rear tarp overhang pieces. They are to be cut out as right triangles 8 x 30 inches. My high school geometry tells me that the long side of these right triangles will only work out to 31.05". The foot ends of the main body of the tarp are shown as 33". Both the rear overhang and the tarp body use the same felled seam method of joining their respective halves.
Simply put the tarp body is going to be wider at the foot end than the longest sides added together of the rear tarp overhangs.
>>It’s like putting together a jigsaw puzzle, only you have the option to resize the pieces if necessary to make things fit<<
Carefully check out all of the measurements before you mark and cut that nice expensive cuben fiber. Check three times, measure twice and cut once. :-)
Pay attention to the modification of the rear tarp overhangs that Jay mentions in the Part 3 - Tarp article.
>>This is the most difficult seam to sew in this project, because it’s hard to sew the felled seam around the apex’s corner. You might need to add a small pleat (which can be tucked under the center seam) as you sew around this corner.<<
The above quote refers to sewing the felled seam at both ends of the tarp body that join the overhangs at each end to the main tarp body.
Are you sewing, bonding/gluing or taping your seams? Will you be using a catenary curve on your ridgeline? If so follow this link below to a catenary curve calculator spreadsheet.
cat curve calc
FWIW I found that the front overhang was a little long and low. I am considering installing a waterproof zipper in the front overhang to ease entry and exit.
Good luck on your project! Post pictures of the finished project! Give us a field test report after your first trip! :-)
Party On ! 2010