I wasn’t feeling well today (sore throat, could harldy swallow), but after a nice long sleep-in and a nap in the afternoon, I went out to the garage partly because I wanted to sweat out some of the demons. I didn’t take a ton of pictures, but I managed a few.
I broke out the c-frame and dimpled the skins.
First up, skin dimpling.
I did much better on the trailing edge dimples than last time (see this post).
This is the worst one, but it still looks great, and is hardly noticeable unless you are really looking for it.
After dimpling, I wiped down all of the scuffed areas with MEK to rid them of fingerprints (oils) aluminum dust, moisture, etc., and then primed.
Primed interior. Notice how I leave a lot of the blue vinyl on the skins? This helps keep weight down (although undoubtedly adds to build time while I painstakingly trace around the stiffeners with a marker and use those lines to devinyl.
Moving back to the skeleton, I mounted a one-leg 1/4″ nutplate in the forward tooling hole of the counterbalance and tip ribs. This will hold any future weight I need to balance the elevator with paint.
I used an undersized countersunk screw in the tooling hole to help locate the nutplate, then drilled one hole and clecoed from the back.
Both holes drilled, and the main hole enlarged to something a little larger than 1/4"...I can't remember...maybe 5/32"?
Next, I moved back to the spar. I have read where a few people have added a hole in the lightening hole area of the elevator control horn/spar area. The right hole is for manual trim or for the (what I’ll call “retracted”) jack screw and wiring runs for the electric trim motor. I, like others, don’t like the idea of the wires and jack screw sharing the same hole, so I drilled another hole, in which I will add a 3/8″ snap bushing.
Pilot hole eye-balled.
Crap, I didn't even get a picture of the final size hole. (I drilled it to 3/8".)
After completed the extra hole, I noticed the skin was dry. Nothing to stop me from backriveting, now.
Rivets place in, and taped to, the first stiffener row.
Same thing with the trim reinforcement area.
After backriveting the trim reinforcement. Man, this makes me happy.
The next couple rows, done.
The bottom half went smoothly. The top half now has rivets taped in place.
Where are those stiffeners?
This isn't a very exciting picture, but they are all riveted.
Here's the inside.
I love this picture. This is the trim reinforcement plate area.
So nice. (That scratch at the top is very superficial. It'll buff right out, I promise.)
Biggest lesson today was about the aft-most rivet in the stiffeners. When bending the skin out of the way to reach that rivet, everything twists out of alignment. If you start with that rivet, it is easier to make sure everything is flush than if you rivet the forward ones first. Start from the back and move forward. You will get better results.
Andrew's RV-7 Build Log 