September 2001
This month's job was to bond in the flap hinge arms. I made up the templates from 12mm MDF. The diagram of the template in the manual
shows quite a shallow slot at the base of the jig, but I found that it needs to be about 3-4cm to ensure that it contacts the leading edge of the
flap. The tip and root closeouts are fiddly, but straight-forward. The manual suggests cutting the slot for the centre arm with a 5mm drill but I
was a little nervous of the drill cutting through the sides of the rib if it wasn't held perfectly vertical. Consequently, I decided to set
about it with a combination of Dremel, knife, chisel and screwdriver. I cut through the skin with the Dremel and then use the knife and
screwdriver to dig out the foam. I cleaned up the sides of the slot with the chisel, removing the excess foam. Once the slot was complete
I bonded in the arm with flox which was a little messy as you have to force flox into the hole in the arm as you push it in. Finally you need
to line up the arms with some string:
 |
 |
 |
Template glued to flap with hot-melt glue
Note the set square bonded to the
template to ensure the correct angle |
Root close-out |
Aligning the arms |
One thing that came to light later was that the holes in both flaps were slightly misaligned. The misalignment was very small and my guess
would be that the string sagged in the middle when I was setting the alignment. I don't know what I could have done about it, but you might
find a better way.
October 2001