I like it, a fast and informative response. There was a few things I didn't know about the build so, with that said:
- I was thinking the tip was in the 10-12cm range when you made the comment about being too flexible. My thought was ply, with lightening holes, might be a better option
- I didn't realize the arch was 19mm thick. I still like the idea of a piece of ply in the structure but I'd go with a piece of 1.5 or 2mm sandwiched in the middle instead
- I see your point on the built up spar, not really a reason to change it.
Here in the US, we don't have a heavy model inspection to deal with so it does make a difference when you have to deal with a weight limit vs red tape issue. I know, with my other hobby of building and racing scale hydroplanes, weight is an issue as well. I build a majority of the boat from 1.5mm birch aircraft grade plywood(the same kind used to make wooden ultralite home built manned aircraft) but some of the framing is 3mm while a couple of frames are 6.5mm, the largest being right at the back of the boat. To cut weight from the heaviest parts, I laminate two pieces of 3mm together, after cutting lightening holes out of the inner piece, saving 30-40% over the solid piece. Where ever possible, I also cut lightening holes out of the thinner ply as well. By the time I'm done, I can usually save a good 40% in weight so I do understand what you're trying to do.
Nice the know the club is still there, even if under a different name. I'd love to make it back to Perth again, just to see how much it's changed over the years. Just wish it wasn't over 10,000Km and 10-15 hours in the air just to get there. Maybe, when this virus crap is over, the wife and I will be able to make it down for a week or two as we have people to visit in New South Wales, Victoria and South Australia. Wouldn't be hard to make it to Perth as well
