Wednesday, December 10, 2008

Inserting the final high density core into the rudder blade

The final high density insert has to be wrapped in carbon fiber (F-22R option) and helps to create the longitudinal rigidity required in a modern lightweight foam rudder.  The high density foam is tailored in thickness so that further uni-directional carbon can be added on top of each side without adding thickness to the rudder blade.

I wrapped the upper and lower halves seperately so that it could be held for wrapping.  You can see the plastic stretch wrap which really helps to hold the carbon cloth in place.  It also allows all the excess resin to be squeezed out to either end.  

For some reason I decided to shape the foam before glueing in this core.  It probably would have been easier to insert the tailored wrapped core into the original rectangular block of foam, and then do the shaping.  Inserting the core after shaping required the use of some simple jigs, spacers and clamps to make sure there was no twisting or mis-alignment in the blade while the epoxy glue was hardening.

The offcuts from the original blade block of foam were put to good use.  The operation was successful and I am now putting in the rebates for the uni-directional re-inforcements.

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