The LE assembly is not "built" in the cradle. The LE skin is drilled to the LE ribs while the LE ribs are cleco'd and temp bolted to the main spar, the LE skin strapped to the ribs. Then remove the LE skin, debur and dimple ribs and skin. Strap skin back on. Same as with wing tanks.
Then you put as many clecos in the LE assembly as you have before you remove it from the wing (main spar). I filled all holes. That keeps the assembly aligned when you remove it from the main spar and put it in the cradle. Really, it's all in the manual.
I really don't see how you can rivet the LE skin to the LE ribs with it on the main spar. On the RV-4 there are no lightening holes through the main spar in the outer bays. I guess you might be able to do it by reaching through the lightening holes in the LE ribs, but why make it so difficult?
Originally Posted by JonJay
Interesting. From a fuzzy memory.....
On the 6, you built all of the wing ribs to the spar, then jigged the skeleton. The Fuel Tank was installed and Main skins where riveted on, then you ran a long 1/4"x20 threaded rod through the tooling holes in the nose ribs to insure alignment. The LE skins where than strapped down into place with cargo straps and drilled. Riveting the top side was easy, then the back side by peeling the skin back and finished up through the lightening holes. The concern I would have is by building the LE assembly in a cradle, how can you insure alignment of the LE skin to the Tank profile. If they don't fit, they don't fit. With the strapping down method, you have some give and take through rib and skin adjustment, and even some shimming if necessary.
It has been a long time, so my memory might be a little fuzzy on sequence, but we never used a cradle to build the LE, only the tanks.
I am not sure if the RV4 wing is any different or if they amended the build manual, or perhaps there is just more than one way to skin this cat (no pun intended).
As long as it makes sense to you and you can move forward, that is all that matters.