Dave’s RV-7A Building Log

It took just a little more coaxing to get the F-684 gussets fitted. Putting in another slight bend where the gussets hit the firewall angle is the key. I then drilled the gussets to the firewall angle by peeling back the side skin. And finally I re-clecoed the side skin and drilled through the side skin, aux longeron, firewall bracket, and gusset.

Next I started fitting the F-902 bulkheads. It’s not much of a bulkhead compared to the others. It’s just two side pieces. I had to file the lower slot slightly and do some slight flange bending and fluting, but otherwise it fit nicely.

I put in some serious hours on the project today. I first worked on the angle clips that hold the forward skin stiffeners to the firewall. I clamped the angle clips to the stiffeners and then removed them both and drilled and clecoed them together. Then I put the assembly back in and drilled the angle clips to the firewall angle. Worked pretty good.

I then moved on to the lower longerons. The replacement angle arrived last week, so I was able to cut these to length and cut back one leg of the angle at the forward end. I then trial fitted them and put a slight twist in the angle. Once I was satisfied the fit was good, I drilled the bolt holes through the lower longeron and into the firewall bracket. I debated about whether to put the lower skin back on and drill the rest of the lower longeron, but decided to wait until I had the other forward parts in place. It’s much easier messing around in the forward fuselage area with the bottom skin off.

I next attacked the F-684 gussets. The plans have you cut out an odd shaped area, make two bends, and drill multiple holes. Doing all of that took 2 hours for the two of them. Very time consuming. It would sure be nice to have this part pre-punched. After all of that fiddling around, they did not fit well. I had to file away more of the cut out area to make the gusset align with the bottom of the skin stiffener and 1/8″ back from the firewall. Once that was fitting better, the bends were not working well. That’s when I decided to call it quits. Now, after looking on Matthew Brandes’ site, I see I am not alone. I was thinking that one additional bend would help things align better, and that’s exactly what Matthew did.

I cut the holes in the bottom forward skin for the tri-gear legs. Also enlarged the holes for the brake lines.

Fitted the auxiliary longerons and forward skin stiffeners and drilled them to the side skins. These all had to be shortened about 1/8 to 1/4″ and angled on the ends. I also fabricated the angle clips for the stiffeners, but didn’t drill them yet. I read on someone’s site that it’s easier not to drill the angle clips from the plans, but to wait until later. That does appear to be true.

Did a little bit of trial fitting of the forward skin stiffeners and auxiliary longerons.

I started off measuring everything on the firewall again and then finally drilled the two holes on either side of the bottom of the firewall to lock it in place. I then fumbled around with the fit of the upper bracket in the longeron. It just wasn’t fitting well. I won’t detail all of the iterations, but I ended up trimming the longeron back another 1/8″ because it was interfering with the bracket, and then clamped it together with a piece of 2×2 nested inside the bracket to give a better clamping surface.

Before drilling, I made the F-704L straps as a break from the firewall fitting and had dinner. After dinner and a bunch more measuring, I went for it. I drilled up (or downward relative to the plane) on both sides of the firewall. I looked ahead in the instructions and didn’t see any mention of when the bottom flange should be drilled, so I went ahead and drilled it along with the bottom angle. And then after more deliberation, I finally drilled the longerons to the upper firewall brackets. I spent more time measuring and examining than anything else, but I’d rather not mess up this part. It turned out great.

Drilled the other longeron up to the F-704. There are a ton of holes in these longerons. There’s going to be a lot of deburring and countersinking coming up. I then trimmed the longerons to 3/4″ short of the front edge of the side skin and drilled the longerons all the way forward. And then the step I’ve been working toward, I clamped the firewall and forward bottom skin onto the fuselage. The thing is really looking cool now. Makes a nice Christmas present to myself.

I drilled the holes in the side skins to 1-1/2″ for the step tubes. I saw a suggestion to drill this larger to 1-3/4″ so that the weld around the step tube would fit better. But then you end up with a gap under the step tube. I drilled to 1-1/2″ and then drew a line 1/8″ outside the hole and trimmed to that all the way around except at the bottom. It turned out great, but I’m not sure it was really worth all of the trouble. The gap would have been small and inconspicuous if I had just made the hole 1-3/4″ to start with.

I then fitted the side skins to the fuselage. I clecoed them onto the F-705 and then the F-704. I’m having the same alignment issues as Dan C., so I think I should start clecoing at the F-706. For now I’m just going to remove the skins and do the conical bend at the aft bottom corner.

I also realized that I forgot to put the F-704 bulkhead halves back together. I need to take care of that as well.

I spent quite a bit of time today just looking at the plans, looking at the structure, looking at the parts, and just figuring out how things all go together. I also cleaned up the aft and center skins a bit. Since I took all of the plastic off, they look awesome but had some oil splattered on them from the rivet gun. A little bit of citrus degreaser and they look really nice. Need to get it all looking good when guests take a look over the holidays. Or maybe I just wanted to admire the great progress so far.

While waiting for some help with the riveting on the aft fuselage and the joining of the aft and center parts, I started looking at the forward fuselage drawing. I decided to fabricate a couple of the angles, but only managed to cut the two parts 1″ short. I’ll have to order some more angle. Luckily it only costs $7.