Ivan's RV-7

Finishing fitting the stiffenersTimer icon4h

February 25, 2023

Finished fitting both of the stiffeners.

The first step I did was to fit the angle clip to the right side stiffener. Since I did not drill the clip, I could place the holes anywhere I want them. So I drilled the holes in the stiffener first, keeping their location such that I get enough of the edge distance of both the stiffener and the clip. Then I used my long 24" drill bit to transfer the hole to the angle clip.

Drilling the angle clip.

To drill the hole through the firewall angle I used the same technique. However, since I had to bend the drill bit a bit too much, it snapped!

The long drill bit snapped!

Luckily, I drilled through the firewall angle at that point and had a mark on the angle clip, so I finished the hole on the workbench, then reamed all the holes to #30. To ream the hole on the firewall angle, I unclecoed the skins. Then I saw this.

The holes don't match?

At first, I thought that I messed up something really bad but then realized that the firewall sagged without being supported by the skin. Clecoeing skin back put the parts in alignment again.

All is good!

And this is what it looks like on the F-704 bulkhead side.

A closer view.

Then I moved to work on the left side stiffener.

Fitting the left side.

Since I didn't have my #40 long drill bit anymore, I needed a different plan. It turned out that the top two holes I could drill with the angle attachment. However, the hole through the firewall angle was too close to the firewall.

To drill it, I marked the location of the clip, unclecoed the skin, and drilled the hole through the firewall angle from the outside. Then I put everything back together and marked the location of the hole on the clip by twisting the drill through the hole in the firewall angle by hand. This left an indentation on the clip, which I then center-punched and drilled. Everything fit together well in the end.

The angle clip fitted.

After that, I reamed the holes to #30.

Then I started fitting the right lower longeron. I trimmed it to fit, then clamped it. Did not drill anything just yet.

Fitting the lower longeron.