Stjohn's RV-7

4 hours.

Yesterday was a lot of not-so-fun stuff positioning the bottom cowl to get it into position to mark and cut the bottom and sides. I have to concur with the general opinion that the instructions at this part of the build suck a thousand sucks. They’re opaque, terse, and confusing. Fortunately, the drawing is good.

Once I cut and shaped the front part to get a decent fit, I marked the bottom, took it off, then trimmed off the excess so the cowl could slide up into position. Then I had to do the fitting dance again, after which I marked the trim lines for the top sides and back. I took it off again and made the cuts. The fit isn’t utterly godawful, but it’s not my favorite work, either, so I set to work on the hinges. I got the bottom hinges drilled, then knocked off to go to a friend’s birthday party.

Today, I drilled the hinges for both the cowl halves and the side firewall hinges. Lots of deburring and countersinking. I have one side hinge left to deburr and csink, and those can probably be riveted on.

3 hours.

The fitting of the bottom cowl continues. There are lots of ways to fit this thing, apparently. Trim the bottom to the top, trim the top to the bottom, and the science-y way, which is to draw a line bisecting a 13 1/4″ circle, then extend that line all the way out and down the cowl. Well, that ain’t gonna work. For one thing, I don’t have the kind of equipment necessary to make a perfect 13 1/4″ disc to use for reference, so that’s out. The flange up front fits OK on the left side, but it’s total crap on the right. It’s not even the same shape, really. I tried hacking off the flange at the corner where the fit sucks the most, but I need to cut it down some more.

However, I was able to get the areas on the inlet marked for trimming, which will enable a better fit along the side. When I cut the top cowl, I may have goofed. The right side wraps around so it extends 4 1/8″ down past the line of the top skin. On the left side, it extends down 4 3/4″ which is a considerable difference. However, I don’t think it’s going to cause too many problems.

Everybody says you can’t really trust the edges of the fiberglass cowl pieces, and I don’t. But hopefully I can get a decent fit on the bottom cowl this week.