Windstar's frame came with the boat, not sure of its origins but it works pretty well. Remarkably, Dennis from Quinte canvas was able to make a cover that fit very well from my emailed dimensions.
Key to the frame's strength vs the more typical backbone-and-ribs are:
- the vertical posts supporting the backbone via a T fitting. (same fitting as each rib half) which I tie in place at the foot so they can't move.
- the longitudinal tubing along each side, running through a crossover fitting. The frame is bungeed or tied to the toe rail at every crossover.
- One of the ribs is (now) inserted into the stanchion socket. (I figured this out this season, photos are a few years old. You can see the 4th rib from the bow is beside a stanchion base.)
If I were to build from scratch I would size the ribs so that as many as possible could be inserted into the stanchion sockets, adding any other ribs between as necessary.
The frame pieces are stored clamped onto a length of tubing, the ribs in pairs.
I have yet to devise an part-identification system that I am happy with.
The component parts can be sourced industrially and are known as structural pipe fittings (or similar). some links and images at the bottom of the page.
Links to the bits and pieces below are examples only:
Here is the crossover fitting