Working on the F-796 parts - 2 hours

Not a big build day. Very unmotivated today to spend all day in the garage. I did manage to cut the F-796B angles to fit inside the longeron/stiffeners.


I didn't reference Van's dimensions on the plans...I just cut them according to the fit. Also, I did my homework last night on the F-796C&D shims and it appears that everyone seems to have issues with the fit. So I decided to shape them to the curve in the bulkhead rather than cut them down. A little time on the sanding station and they fit well. An important note...its only the top half of the shim that begins to interfere with the bulkhead....so trim the spacers according to the fit, and not the entire length of the shim.
Unfortunately I didn't take a picture of the finished product, but you get the idea.  

Worked on the F-772 bottom skin and F-796C&D spacers - 4 hours

I started the days build session by cleaning up the F-772 bottom skin. I feared that I was scratching the aluminum too much by taking the bottom skin on/off all the time. I broke all of the edges with a file, and then used a 3M wheel to smooth them out.



Next I used the edge forming tool and rolled the edge on the aft potion of the skin.


Next step that I wanted to do was to locate the hole on the upper tabs of the F-902 bulkhead to the longeron. They is virtually no room to work with here so before I did anything I marked minimum edge distance on the longeron.

On the tabs. I installed them temporarily, marked where the tab overhangs the longeron. and then started to mark minimum edge distance on all 4 sides.


I then drilled the #30 hole and confirmed proper edge distance. Next I Installed the bulkheads in the fuse and very carefully marked a pilot hole in the longeron with my 90deg drill set. I have just enough edge distance to work with. My drill set is too bulky to drill these holes, I will just need to finish drilling these when I take the longerons off to countersink them.
 
Next I turned my attention to the F-796C&D spacers. I had cut these out some time ago, but now I need to drill the top 3/32" hole. So I got creative.

Now when fitting the shims to the bulkhead, you will notice that you will need to make some adjustments.

Reading Mike Bullocks RV-7 build log, he notes that he had to trim about 1/16" off the bottom shim, and 1/32" off the top shim.. I'm going to do a bit more research on this.

Installed the F-902 bulkheads (Round 3) - 3 hours

I'm tired of talking about how I installed the F-902 bulkheads. I've done it twice already, Always messing up the holes to the F-7101 gear attachment web. (It is a bit tricky to get the fit right).

I'll be brief. I did everything as I did before, Ensured the F-7101 web was tight against the longeron. I used 0.040" scrap to simulate the bottom skin (yes it matters). I used a few clamps on the assemble to hole it all tight. After drilling, I installed the floor skin to double check all of the alignment. The result is excellent. Finally a F-902 bulkhead with correct holes drilled to the gear web. Sheesh!




I then removed the floor skin so that I can work on the lower tabs (upper in the picture.....remember the fuse is upside down). I marked the edge of the longeron on the tab (in red) and then I marked out lines offset from the edges by about 0.245". This gave me an idea of where I want to place the #30 hole.

I then re assembled and then transferred the hole to the lower longeron.
The fit is really good.

Began drilling the F-772B floor stiffeners - 2 hours

A while ago, I had already cut and notched the center two stiffeners for the correct fit. Now it's time to install and drill the F-772B floor stiffeners. Before drilling, I test fit the F-782C center cabin cover since the holes do not appear that the sit at the center of the angle. In the end this is not a concern as the cover nests inside the angle very well.

 I began drilling a pilot hole at the center of the stiffener and worked outwards. I began to notice an inward bow as I cleco'd.


I also checked the bow in the side skin where the F-719 stiffeners are.

Yup, there is no doubt that the joggle (z-bend) in these angle parts result in the fit from needing a bit of attention. I do recall a time when I was talking with Vans tech support and they had recommended a small shim in these areas. I am going to ask the question to the build group on-line and see what others have done to smooth these out.

I have posed the question on-line but have not got a whole lot of responses. A couple of people say that it will be fine once riveted, and one suggested cutting the joggle off and riveting on an offset extension with shims. Nobody mentioned shims as Van's indicated. I don't know what I am going to do with this just yet

More F-719 work (Round 2) - 4 hours

I had ordered another F-719-L stiffener from Van's and went to work re-drilling and fitting the whole piece. I am now becoming a master a doing these...This is my third left stiffener.

Long story short. It came out perfect. Holes for the side skins and rudder pedals all drilled and are excellent.

I'm still concerned with a bit of an inward bow where the joggle is.

Match drilled the F-772 bottom skin - 2.5 hours

Thinking on what to do next, I figure at some point I need the get the F-772 bottom skin in place. And right now seems like a good time.

Before I started, I felt it wise to drill a couple keeper holes to aid in getting the skin fitment correct.
I choose the #40 holes towards the aft ans one of the #30 holes.

Then I began to drill all the holes. This included the holes being drilled through the lower engine mount. I was concerned about the edge distance here as there is very little room to work with. But as you can see a do have enough edge distance. In fact the blue line is drawn at 0.225" rather than minimum edge distance at 0.219" just for a bit extra.


All of the holes drilled and the floor skin is cleco'd

Drilled the F-902 bulkheads for the second time - 3 hours

With the recent Vans shipment, I ordered new F-902 bulkheads, since drilling them to the F-7101 gear attach web can be quite tricky.

I already have the spacers cut for this area out of 0.032" but the spacers do come quite close and touch the longerons & stiffeners. So I decided to mark them and give them a notch for clearance to help ensure good fit.

UPDATE: Do not follow the installation picture below. It is very important that you use a piece of 0.040" scrap between the F-719 longeron and the F-770 side skin. Later when I went to install the floor skin, I noticed that the holes to the gear attach web are slightly offset. 


As you can see the fit is very close and I fear that it may prevent the gear web from sitting flush against the angles.

With a bit of work on the 3M wheel the notches are easily made.

I was then ready to begin drilling the holes to the F-7101 gear attach web.