Nigel. People tell me I’ve been very rude to you. To be entirely honest, this is not entirely unintentional. You may not know about it, but if you sniff around the web (rc groups is a good place) you can find the story. A guy promoted a thing called Hang Ten which also looked like an Open 60 and produced tooling to vacuum form toolsto make it. He published pictures of the thing sailing on somebody’s swimming pool in Force Damn All - and then started taking people’s money.
No boats were ever delivered - I suspect because they then found that in Force 0.5 the thing fell over on its ear. I think that people all got their money back - but it seems to have been an uphill struggle.
Your open 60 Footy project is worryingly similar. You are trying to make a boat that it seems to be has to be lighter than is possible with a Footy in order to work, no matter how clever the composite engineering - the weight of the electrics makes this almost certain. I’m not saying that you are dishonest (and I’m far from sure the Hang Ten guy started out as anthing but a starry eyed enthusiast), but it is my fear that the Footy class can do lots of disappointed customers in rapid succession. This may help explain my hostility to your Open 60 type project up to now.
It may be, of course, that you are right and that an overweight OPen 60 lookalike will work. Nothing is impossible. I have been playing with the design of boats for long enough to know that anyone who says ‘this will’ or ‘this won’t’ without any letout is a fool.
The other point I have been trying to make is that carbon is not necessarily tha nswer to all things - not because it isn’t a beautiful material but because in these very small structures with tiny loadings, it is very difficult to get carbon cloth or anything else that is light enough to make sense. You might care to look at 16g/m2 carbon tissue. This is a few (you can almost see through it) carbon fibres laid at random. It is not efficient and the resin takeup is high but it actually produces structures that are quite adequate in terms of tensile strength from one or two layers (I guess you are using light cloth of around 100g/m2). The problem is that anything so thin (approx 0.2 mm per layer) has virtually no panel stiffness - so you have to use some sort of sandwich.
My rather sarcastic point about the rudder was that, given the carbon available, you can produce a structure that is vastly over the top in terms of strength, but when you look closely, one using more conventional modelling materials is actually lighter.
If you find model yachts fun, and Footys in particular, thern if you want some hull dsigns, I can provide some - as can various other people. For my own part, I do this for fun. If you want a design for high-tech construction, it is free - off-the shelf or custom. If you want to discuss anything along those lines, you can send me an email from this forum and we can talk.