The Familiar Itch of Carbon

Week nights and weekends have seen a little hive of activity over this flap. We have been aiming for this bank holiday weekend, and it looks like we're on target. Last night saw the final trimming of the lower flap box that we salvaged off the previous flap and suitably modified. We also cut the leading edge slots for the slot gap fingers and bonded these in. On the previous flap we bonded the slot gap fingers onto the outer surface, which frequently resulted in one or two popping off and it wasn't a particularly aerodynamic solution; this time around we have pierced the leading edge and have bonded a post right through the structure. This should help stiffen the leading edge. This one uses Rohacell as a core, which isn't easily thermo-formed, and that has meant we had to stop it short of the nose radius.

Today we will trial fit the wing together and run the controls through their range to check the functionality, skin the wing, and be ready for sailing on Saturday. We're eagre to get this boat back in the water where she belongs.

Andrew

How to mend a broken wing

It's sunny outside. Warm too. But Team Invictus has been indoors studiously designing, moulding, sanding, gluing and bandsawing. The new flap is coming along steadily - we have revised a number of points of the design for an increase in bending stiffness, ancreased bond area, slightly tougher ribs and revised detail to the twist mechanism. The trailing edge is now assembled and bonded and this evening we will be bonding the spar into the leading edge.



We have also been doing a bit of testing: there were concerns about how much twist we could put through the flap before it gave, and what that failure mode would be. So we tested half of the old one in pure torsion and the attached image captures the results. We got to just over 20 degrees (i.e. 40 on the full flap), which is more than we expect to need, and failure initiated by buckling in the leading edge sandwich.


We have also been enjoying a bit of publicity: this month sees us reviewed by Jeremy Evans in Yachts&Yachting and also in Yachting World.

More soon!

Andrew