Not much work has been done since my last post - I'm expecting the shipment of bamboo to arrive in the next couple of weeks or so then the serious construction can begin! I haven't been entirely idle however. I've had a couple of new ideas for the connection details I'll try out next weekend.
The first involves how the vertical sections are connected together with the horizontal frames. In the current mock-up I used bicycle innertubes for this connection - it seems to work but makes me a little nervous because of all the forces this connection needs to resist. As an alternative I'm going to try using flat 1" nylon webbing with a ladderlock buckle that I can crank down nice and tight - the buckle will be the weak point.
The second involves the compression cross members. Currently the cross members pass above the vertical "X" intersections in one direction and below in the other direction. This causes the cross members to bow away from each other creating a 4"-6" gap between them. I then use paracord lashing to pull them together and bind them - this causes them to push out a little more and deform into a sign wave shape which looks really stressed and not as beautiful as the single sweeping curve they exhibit before binding. What I'd like to try is bracing the cross members in their initial bowed state using a short length of bamboo (4" - 6") between the bowed pieces right at their crossing point and then lashing over that, binding it all together.
Pictures and a better explanation to follow once I complete the experiment.