Friday, 15 January 2016

C17 Flap canoe test

I have had some concerns over the operation and construction of the flap canoes.  I sketched up a few ideas, and this is what I've ended up with.  The flaps operate in much the same way as the full-size, with a hinge at the bottom of the canoes - for me this will be an arrangement of 3mm glassfibre board bonded to a central core of 3mm liteply.  The hinge itself will hopefully be a 4mm ball-link with a 4mm carbon pin, and a clevis on the mating part will be glassfibre board.

Shown here in the model are canoes 1 and 4 (4 being most outboard), and the flap is deployed.  Canoe 3 will be identical to these, but canoe 2 will be where the "magic" happens.  There will be two core plates on number 2, with a 6mm gap in between them.  This will allow a linkage from a servo to pass through and link up with the rear part of the canoe, close to the pivot, which will give me the required large throw.

All canoe cores will be sandwiched in blue or pink XPS foam, then glassed.  Flap servo access will be in the top surface, just in front of the spoilers.

I have also done some work on the fold-out parts of the landing lights, just for Dave!

Full size :