Ivan's RV-7

Preparing the front spar assemblyTimer icon4h

May 23, 2022

Going back to rebuild the vertical stabilizer front spar.

Since I have damaged the vertical stabilizer front spar assembly, I decided to rebuild it from new parts. Van's Aircraft support told me that I can sand off the damaged sharp corners, but if I want peace of mind, components are not that expensive πŸ˜‰.

The first step was to drill all the parts together. Instead of drilling them together with the skin, I simply opened the holes to the final #40 size with the reamer.

New parts are drilled and ready to get cleaned and primed.

Then I cleaned them, etched them, and primed them!

Parts primed.

After that, I figured out how to drill the remaining hole in two of the nose ribs. I planned to cleco them in place hoping that the dimple on the skin is small enough so it would not interfere too much with the flanges. Also, the flanges could bend inwards. It worked just fine -- pulling the skin on wasn't too difficult.

This is how it looked:

Aligning an existing hole with the rib.

Then I drilled four of these holes, dimpled them, and riveted the front spar assembly. As in the first time, I had some trouble riveting the bottom ribs to the spar. The side ones I set fine with my manual squeezer. However, the middle one was not straight. It might have been okay, but I decided to replace it. I drilled it out and put a new rivet, but in the opposite direction since it was easier that way. Now I have a revolting rivet looking in the other direction!

Rivet sticking the opposite direction!

Finally, I clecoed everything together until the daytime so I can use my rivet gun to assemble everything.

With a bit more time spent in my garage, I started working on rudder stiffeners. They come in eight pieces of long stock, two stiffeners each. The goal is to cut them to the correct lengths. I started by making an angled cut of each stiffener. The goal is to deburr them on the wheel, making sure the angled cut is all smooth and polished, then to cut them to length and do a final deburring.

Rudder stiffeners stock. Made rough cut of rudder stiffeners.