Design and mockups
My solution for the fin mounting problem was to put little brackets on the end of the fins. This would allow me to screw them very easily onto the frame.
I ordered over 40 metres of cable braid; this was my second time sleeving and was very pleased with the result.
At first, I thought it wasn’t necessary to mark the line along which I wanted to bend the fins, but I noticed on my first bend that without the line, it would take a lot longer as well as being very hit-and-miss. I used the board to make sure all the fins were the same width. As you can see above, my efforts paid off.
I made a mock-up of the corner section of fins. I could have calculated the angles precisely, but as you can see from the scraps, I used trial and error instead. Then I attached it and the other fins to confirm that the plans I'd made to mount them would work.