More fitting F-748 baggage tunnel cover and started flap assembly - 6 hours

 I noticed that the F-748 baggage tunnel cover needs to be fit with the baggage bulkhead panels installed. When I did this, the baggage tunnel cover fit wasn't great at all. Towards the aft, the very thin skin of the cover has quite a bow to it and a decent gap between it and the floor. I spent some time with it, uninstalling and reinstalling but nothing worked. 

After reading about it on other blogs, seems this a very common issue. It seems that others have simple re-bend the end of the piece and then oblong-ed the two aft mounting holes. Since this is not a structural part I see no reason to do the same.

I set up the piece in the vice and I will re-bend the end of F-748 about the thickness of a popsicle stick. Once clamped and set up, I used a rubber matter to re-shape the bend. Once the mounting holes were filed oblong. The cover mounted to the floor so much better.

Next I need to start in on the flap assembly. I need to fabricate F-767. The plans do not give you dimensions to work with so I imported the shape into AutoCAD. Drafted the part and then I could reproduce the part with the use of a template.

With F-767 fabricated and drilled to the F-766A cover. I am now able to back drill the top most holes in F-767.

With the rough fitment of the front flap assembly complete. I was ready to fabricate the F-785B. At this point I realized there was no need to dimple the two mounting holes in the baggage floor. Im not the only builder to have done this. (I could always dimple the two mounting holes in F-785B - It works...i've tried). but I chose to leave it for now. 

Since the band saw is set up, I began fitting the F-983A fuel valve plate and F-983C valve cover.

I trimmed the valve plate on the band saw and flipped it upside down. 

Fitting the F-748 baggage tunnel cover - 1 hour

 Wasn't entirely motivated to build today. I worked on fitting the new F-747-L baggage floor I had ordered some time ago. The one I have (The one painted dark gray - has some cracks in a couple of dimples). I've needed to get this new floor prep'd and dimpled and tonight I decided to get it done. 

 

With the baggage floors fitted. I am now ready to drill, dimple, and fit the F-748 baggage tunnel cover. (One item that I should have done was to use an edge rolling tool on the edges). Not required but it would have worked well here.

 

Fabrication of the F-741A angles - 3.5 hours

 I started the build session by installing the forward and aft seat floors. In order to fabricate the center tunnel cover (and F-741A angles) the seat floors need to be installed.

I also installed the fuel valve cover and plate just to see how it all looks and fits.

I started fabrication of the F-741A angles according to the dimensions given in the plans. I chose to leave the material long at this point and I will trim to fit as needed rather than rely on the length given on the plans.

Once the first hole is defined, I clamped the angle to the seat floor and back drilled the next holes using the seat floor as a template. 

I only used the seat floor to define the hole and i finished drilling on the drill press. 

I put the seat floors back together, cleacoed the parts in, and took measurements. I was ready to start trimming the Aft of the F-741A angles. 

In the end, the fit is good. I'm going to stop here and get the flap system set up and then I'll finish the tunnel cover.

 

Adjusted the seat anchor openings - 2 hours

 I spent a couple of hours today enlarging the 4 openings on the F-742 aft seat floor for the seat belt anchors. I sketched out about 1/8" total of extra space on the forward side of the hole. Initial cuts where made with the dremel. Final trimming was done with files. 

 

Fixed seat belt anchor holes - 1 hour

 One of the issues I have is that the holes in the F-742 seat floor is that the openings for the seat belt anchors are touching (or just about touching) on the forward side. I took an hour to check fit of anchors and seat floors to make sure I didn't have anything wrong. Looking at other build sites, the clearance seems a bit tight on the fwd side.

 

Finished the F-6111 aft skin reinforcing ribs - 5 hours

 I played with the fit of the pilot side F-6111 rib. I managed to get the rim to sit/fit much better after trimming the ends. The bulkhead interferes just a tad at the top of the rib, so I need to do a little careful trimming here. In the end, this is what I finished with. 

This is what the top of the rib is trimmed like.

I began working on installing the right (co-pilot side). Repeating the exact same process as before, start at the bottom and work my way up. The fitting on this side is a tad more tricky than the other side, but its going. The ribs have a real twist in them....like a real good twist. Here is what they end up looking like after final fitting.

In the end, I'm extremely happy with the fit. Not a quick process....but it turned out very nice.

Still feeling like moving forward. I drilled and trimmed the seat belt cable guides.

F-6111 aft skin reinforcing rib - 5 hours

 Fitting these F-6111 aft skin ribs is a bit of a head scratcher. The instructions are not helpful. Doing some research on them the general consensus is to start at the bottom and work your way up. Trimming only to match the angle in the longeron and where the rib meets the bulkhead.

Firstly I carefully drew a centerline down the ribs. The interesting thing is that the rib flange varies in width along the length so I was careful to account for this. Starting at the bottom where the rib meets the longeron, I found that the angle is 42deg. (A piece of paper was used behind the skin and a pen dot through the holes....connect the dots and the angle is found).  I transferred this to the ribs and cut accordingly. 

Next I trimmed the angle at the bottom of the rib, fit it to the skin/longeron, aligned the centerline with the first few holes and drilled the bottom hole.

One by one I started working my way up. Aligning, then drilling one hole and cleco at a time.

At this point the bottom of the rib begins to rub against the longeron. So I will need to think about trimming this down.

As I work my way up, I now need to start trimming the top of the rib to match the angle with the bulkhead. Very much a guess and test situation here. I trimmed a little bit.

Kept drilling and clecoing, one by one.

As I got closer to the top, I trimmed a bit more as needed, and then I began to see where I need to account for the flutting in the bulkhead in two spots.This ends up being a compromise of sorta flattening the 2 flutes, and creating 2 shallow flutes in the F-6111 rib (Too much fluting in the ribs cause the centerline to deflect too much) 

By the end, I am really happy with the fit and I did a little trimming at the bottom of the rib for the longeron. I'm still not satisfied with it and I'll get this trimmed better later. 

Finished the baggage bulkhead - 5 hours

 I started off the build session by fitting the lower bulkhead to the upper bulkhead and drilling the holes for the #8 screws and the associated nutplates.

 

I then began the process of drilling ALL of the #8 holes for the require nutplates. I marked out guide lines as best I could so that the nutplates followed the lines of the bulkhead.

Then came the very tedious process of countersinking and riveting all of the nutplates. I prime all of my nutplates so there is a bit of time eaten up by prep and paint of these.

The top skin went back on as I will need to fit the F-6111 aft skin reinforcing ribs.