Q) Minimal sewing--my kind of DIY!
A) I bet you could do it with zero sewing because the waterproof Uretek zippers seem to bond really well to the cuben with Hysol. I thought about doing this but I didn't want to take the risk of a zipper failure in the field as that would be quite problematic.
Q) When will you be setting up shop? ;-)
A) This thing took a ton of time to build. I was really careful with all the measuring etc so I probably put about 30 hours so far into it. I had virtually no experience with any of the skills needed for this project, so anyone with some patience could accomplish something similar.
Q) what do the poles & inner tent weigh?
A) The original poles are 450g (15.9oz) and the inner is 594g (21oz). I've ordered some Fibraplex poles for this tent which should weigh half of the stock poles. Cuben Fly + Carbon Poles + Inner should be approx. 39oz or 2lbs 7oz. Under 2.5lbs for a double wall, 2 person, dual door, dual vestibule, decently spacious, freestanding shelter was my goal.
Q) Was the original fly constructed in more pieces than the Cuben one?
A) Yes, my large initial panel that angles across the top of the tent was 4 pieces in the original fly. The end panels are the same and the last corner/door panel was 2 pieces. So my fly is 5 pieces instead of 10.
Q) Why the tie out grommet and not a reinforced line loc as used in other locations on the fly?
A) I didn't think it was necessary. The grommet is lighter than a LineLoc3 and there is very little load on this grommet. I just need it to prevent the fly from touching the inner under wind deflection. I use 2g Terra Nova stakes for everything with this tent except for the vestibules where I use 8g Ti stakes. The grommet is 1.3g and a LineLoc3 plus reinforcement patches and a folded cuben strap is ~4g.
Q) No vents? Could be a clammy situation....
A) The original fly did have two vents. I might add these but honestly I've never noticed a big difference when using the original fly with them opened or closed. Last summer I had a MSR Carbon Reflex 2 which is a very similar shape with no vents and I had no excessive condensation issues.