Sun Dec 14 2008

Floor stiffeners

I actually did some work over the past week, but it consisted of working on the joggle tooling so that the joggle spacing for these floor stiffeners would be 5/8 inch instead of 3/4 inch as originally designed. I joggled these pieces, but just got around to trimming them to length today. Actually when I made the joggles, I got the dimensions wrong on one of them. Fortunately, my friend Brent came to the rescue and loaned me a piece of 3/4 x 3/4 x 1/16 angle that he had left over.

Next, I clecoed the floor skin back on and match drilled it to the side skins and center bottom skin.

With the center two stiffeners held in by magnets, I found an interference that prevented the floor stiffener from laying flat against the F-601? floor attach brackets.

I marked off the area to be trimmed...

...and about five minutes with the sander and files had them looking better.

Now they fit right into place. :-)

Ok, here's the F-782C cover which is supposed to fit between the center two floor stiffeners. It's 8 inches wide exactly. The two rows of stiffener holes are 7 1/4 inches apart. So in order for this cover to fit snugly between the flanges of the floor stiffeners, the holes need to be drilled 7/16 from the vertex, NOT on the centerline of the angle flange like the instructions say. It's frustrating that the instructions can be unreliable in this way.

Here's where the row of holes will go on the center two floor stiffeners.

After drilling, I wedged the F-782C cover in place. It fits perfectly between the two stiffeners. In order to drill the stiffeners, I used some of the magnets which my brother, Chris, gave me to hold the stiffeners in place.

I wonder why I took another photo of the same thing? Shrug.

A short while later, I had the outboard floor stiffeners drilled as well.

The inboard two floor stiffeners need to be drilled to the F-601J. The plans say to drill the holes in the F-601J at assembly, but that sounds way too hard. I guess it's another case where the plans/instructions don't do things the best/easiest way. I decided to uncleco them and drill them on the bench. This is yet another instance where I'm convinced it's better to wait on assembly of the firewall until later in the project.

After drilling these, I clecoed them back in position and used the angle drill to transfer drill through the inboard floor stiffeners.

I also transfer drilled through the F-783B-L & R brackets into the floor stiffeners. There's some interference here as you can see from the way the floor stiffener doesn't lay flat against the bracket.

I filed a radius on the flange of the floor stiffener to clear the bend radius of the bracket and all was well. :-)

Here they are clecoed in position. That's it for tonight...gonna get some sleep.