Unfortunately, my flap brace and bottom skin are already riveted in place. I followed the plans which lead me to dimple and then rivet them both in sequence. However, now I'm realizing the challenge with locating the hinge using this method. I'm not sure I could remove the flap brace without damaging the rear spar at this point because I don't have good access to the inside of the rear spar to back the shop heads.
Thanks for the tips on locating the flap.
So if I understand correctly, you dimpled the bottom skin AND the flap brace - is this correct?
If so, DO NOT countersink the flap hinge as the fix. The hinge material is too soft to take the countersink and you risk the shop heads pulling through the knife edge - and loosing the flap.
As you have the bottom skins on, removing them to fix the flap brace would be a pain. Here is one approach - but I recommend you check with Van?s to make sure:
- Drill out the bottom skin to flap brace rivets that you installed.
- Cut a two pieces of .032? aluminum 1/2? wide that is the same length as teh flap hinge.
- Use clamps to hold this piece of aluminum to the bottom skin so you can use the bottom skin as a template. Drill the holes.
- After drilling, take the piece of aluminum and machine countersink the holes to accept the flap brace dimple. The flap hinge will then go on top of this piece of aluminum.
- Drill out the hinge rivets on the flap. You need to add the second piece of .032? aluminum between the flap spar and the hinge. You need to do this so the flap height is the same with the wing.
- As the flap spar is already countersunk, do not countersink this piece of aluminum that goes between the flap spar and the hinge.
- Hang the flap as discussed above.
I hung the flaps on my RV-8 project a few days ago. While I agree the instructions can be better, I recall somewhere they tell you to couintersink the flap brace.
Carl