Sorry for the delay in replying but I'm now back home in building and drinking mode (hopefully until Xmas) which doesn't leave much space or enthusiasm for emailing.
Rob's had the hulls engineered and I have some pretty coloured pictures showing stress points and including my old university nemesis 'von Mises'. So hopefully we're covered.
Don't expect too many posts until after Xmas, you might get some contributions if somebody starts a topic about sailors and drinking, but they might not be coherent....
Cheers,
Robinho (she thinks it sounds sexy so I'm sticking to it for a while)
--- In harryproa@yahoogrou
>
> Sorry that should have been 60mm x 15mm for the rods
>
> --- In harryproa@yahoogrou
> >
> > Sounds like you are a fair bit further along than the pictures. It is certainly big enough for world cruising and should go quite quickly. A wrap of carbon should hold these bits together and I presume there will be some decent bulkheads here
> >
> > I think Rob is not so much concerned with racing but more concerned with unnecessary weight and stress concentrations which can actually make a boat less seaworthy ( and cost more). I am also concerned about the torque from one mast and rudder to the other beam and how to avoid stress concentrations around the hatches.
> > Personally, I don't see an extra wrap of carbon from mast to crossbeam of any extra value unless you include similar torque transference to the other beam and the rudders. There is the probability that sometimes you will be driving with only one of the masts.
> > Rob has given advice on what the composite engineer recommends and it makes good sense to me. What I have is already 0/90 600g glass over 20mm foam between the rudders and I plan to do an extra wrap of +/-45 600 glass for this high stress area with extra tow directly round the beams, mast and rudders to withstand compression forces, uni glass under the masts and staggered reinforcing to spread the load to the rest of the hull. Around the hatches on the lw hull I will also be staggering another couple of layers. On the ww hull and the ends of the lw hull I am going pretty light. +/_45 400g glass and 15mm polycore.
> > I have finished the bulk of my marking. Just a few stragglers. I can get back to mould preparation and then I will try and draw up some ideas for the rudders.
> > I am getting a bit nervous about stuffing things up but I have to keep reminding myself that the worst that can happen is I stuff up some materials and have to work a few more weeks to buy some more. A beams worth of carbon rods is only $500 worth. I am planning on making four rods inside a 90mm tube . This gives four quarter circle rods 6mmx 1.5 mm right into the corners of the beam. It may be a little more work than the standard design but I feel it is a little more efficient in the use of the materials.
> > I guess yours are going to be about 6-8 times the cross section area
> > regards,
> > Robert
> > --- In harryproa@yahoogrou
> > >
> > > A one metre wide carbon fibre wrap around the hull and roof,on the inside and outside, hull already done. Further strengthening with carbon tow around the masts and beam sockets if I have figured Rob's design correct.
> > > We'll probably have quite a lot more carbon fibre than in the plans,maybe even a figure of eight around beam sockets and masts as well, as I am inclined to have a boat that is more bullet proof than fast. She's to be a worldwide cruiser not a racer so I don't mind losing a few knots due to extra weight.
> > > It's a bit difficult to get this through to Rob as he seems to have a more or less one track racing mind!
> > >
> > > Cheers,
> > > Robinho.
> > >
> > > --- In harryproa@yahoogrou
> > > >
> > > > I just checked out your pictures. This is some beast. I was also going to put the masts through the beams, but came down to deciding to put them adjacent just to the outside. How are you organising the bracing in the hull for the mast?
> > > > I plan on bracing at 45 degrees forward to the rudders support bulkhead
> > > > I definitely need to get into some drawing to illustrate my ideas,
> > > > Robert
> > > >
> > >
> >
>
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