To make up time I missed last week, I did back to back days in the shop this week.
The next step in the rebuild of this 701 wing is making new aluminum caps to reinforce the damage done by the original builder to the tops of the two fuel tank ribs. As you can see here, the holes are kinda randomly spaced and most aren't even clean:
We'll be doing a cap along the front edge as well for the same reason. This will strengthen the upper spar cap angle and make a much cleaner (and stronger) assembly. Before doing this, I did a test fit of the infamously missing replacement wing root spar doubler before measuring it for the bending of the flanges, and I'm really happy with the result of the fit:
Or at least I thought I was until I remembered the small bend in the upper spar cap that needs to be repaired. Looking along the top of the spar cap angle you can see the "wow" (bend) I'm talking about. It's not enough to change the fit of the spar root doubler, but it will affect how squareness of the wing to fuselage join-up::
So, using a bit of my recently learned knowledge about how aluminum "springs back" some when bent, I had to come up with an easy way to take this bend out. First, I taped some mahogany shims on opposite side of the spar cap and to either side of and equidistant to the bend:
Once these were in place, I carefully clamped a 2x2 piece of wood to act as a surface to leverage against:
Unfortunately, you'll have to use your imagination to visualize the next step as I don't have a picture.
Another C-clamp placed directly of the centre of the bend is gently tightened drawing the bend towards the gap and slightly beyond. Once released, "spring-back" takes over and the spar cap returns to the straight position. It took a couple of tries to get it perfect, but it worked. This wouldn't work if the spar cap was broken or kinked - it would have to be replaced at that point, a very time consuming and expensive process. Here is a picture of the now straightened spar cap. Very pleased how this worked out:
Next up, bending the spar root doubler and installing the new caps around the edges of the fuel tank bay. Progress!
New here? Try starting at:
Husband, father and 911 dispatcher. Long time pilot with a licence that burns a hole in my pocket where my student loan money used to be. First time aircraft builder. Looking to fly my own airplane.