Drilled remaining holes in the F-770 side skin - 2 hours

 Before I started to drill the pitot/wiring hole in the side skin. I noticed that the hole I made in the F-715 seat rib (using the tooling hole) does not line up with the pilot hole in the F-770 side skin. I did some research on this and looks like I am not the only one who has done this. (Wirejock has done it as well).I decided to use the hole i made in the seat rib as a guide and ignore the pilot hole in the side skin.

 

Next I drilled the holes for the fuel supply and fuel vent lines in the side skins. Once I was done that I started in on some edge braking and deburing.

Finished installing the nutplates in F-706 bulkhead - 2 hours

 Short build day today, been occupied with a million other things.

I finished installing all of the rivets in the F-706 bulkhead.

Prep'ing the fwd bottom skin and various pieces - 4 hours

I’ve been off the build for a while. My daughter Reed got very sick with appendicitis and was in the hospital for about a week. I stayed nearly the entire week there with her, so the build was on pause. She is all good now, so I am eager and motivated to get back to work. Lots of work was done today and little in the way of pictures to show all of it.

I started the day by deburring all of the holes in the F-772 forward bottom skin. 

Next, I started to work on enlarging all of the rudder cable holes in the F-902, F-724 bulkheads. Clecoing the ribs to a piece of MDF makes enlarging the holes really quick and easy. 

 

I also drilled the wiring/static holes in the F-724 bulkhead ribs.

 

 

 

 

Worked on the F-706 bulkhead - 3 hours

 I needed to spend some time working on the F-706 bulkhead. Lots of little items to do here. In particular I have to dimple a number of holes for #8 countersunk screws all because I have chose the removable baggage and floor panels. It's always stressful dimpling these holes as they are prone to cracking if you are not careful.

I followed the same method as usual. I debured, then used scotchbrite on the dremmel. Switched to #800 grit sandpaper and polished the hole with the dremmel. A little WD-40 and dimple. 

Once all the holes (and there are a lot of them). I drilled them for the nutplate, and then cleaned and spot primed.

Prep’ing the firewall and the aft fuse - 3 hours

 Managed to get to work on preparing the firewall. The powder coated weldments have taken a little abuse with the fitting of the forward fuse parts. So I de-burred, cleaned and primed the outward faces of the weldments.

 Next I started in on the aft fuse. I deburred all the new holes and cleaned them up. I then dimpled all the holes along the longeron and the new line of rivets where the center section attaches at bulkhead F-706. After dimpling I cleaned the area and primed both the inside face and the outside face. 

 

Finished countersinking fuse parts - 6 hours

Managed a good long day in the garage. I completed countersinking all of the fuselage parts. 

The bottom angle on the firewall.

I countersunk all of the forward fuselage stiffeners and floor stiffeners. 

I started deburring and dimpling some of the primed fuse parts I had like the F-623 corner ribs

I deburred and dimpled the arm rests. Broke the edges and cleaned them all up ready for primer.

Deburring parts and made a countersink test piece - 5 hours

 Nice long day on the build today. I managed to debur all of the fuselage "pieces". I use a combination of deburing tools and maroon scotchbrite on the dremel.

One thing that was bugging me....I'm doubting that my information on countersinks might be incorrect. So I decided to go to work on building test pieces out of scrap to figure out if the info I have is correct or not.

Basically what I did was to cut three different thicknesses of dimpled pieces (0.025", 0.032" and 0.040") and then went to work on determining proper countersinks for those dimpled pieces. After much testing, I found the that proper countersink diameters for me, were ever so slightly smaller than the data I originally had.  Now I have an actual standard for proper countersink diameters.

I then went back and double checked my longerons and I am perfect!

 

 

 

 

 

Completed countersinks on the longerons - 3 hours

 Kept on countersinking....Aluminum shavings everywhere.

Completed fuselage disassembly and started countersinking - 4 hours

I completed disassembly of the fuselage and managed to get all of the pieces laid out in the garage. I began looking over parts and it's staggering to see all of the list of items on the to do list that need to happen before I can start assembly.

 

The item I was most keen on getting dome was all of the countersinking. And there is a lot. First I opened up the #30 holes on the longeron. I was very careful not too countersink too deep. This is always a huge concern for me as the data for a proper countersink is extremely cryptic.
Once I was happy with the #30's I then moved on to the #40 holes....Wow there is a lot of them. 

 

Baggage Compartment work - 3 hours

 I need to do a bit of work in the baggage compartment. Since I am in Canada, I have to make all of my panels removable to aid in inspection. Technically the two aft baggage compartment side panels still allow a view of all rivets with an inspection mirror. But I decided to make it all removable. All of the floor  (with the exception of F-705) with me flush screws. Everything else will be regular screws.

Once all of the side panels were installed. I began opening up all the holes to #19.  

Next I need to work on my new baggage floor skin. The other one I had developed a crack when dimpling for the screws so I decided to replace it. Best method I have found for opening holes is to use MDF. Keeps the holes centred. I opened nearly all the holes to #19.

I am now finished will everything I need to do with the assembly together. Its now time to disassemble everything. And so it begins...

Opened the two holes in F-796B to 3/16" - 1 hour

 One if the items on the to do list that I was avoiding was to open the two #30 holes in the F-796B angle to a #12 hole to allow the AN3 bolt on top and a #10 screw on the bottom. Being that not everything is permanently together, I opted to open the holes to 3/16" to get a tight tolerance. I can always open then to #12 later if needed.

I used my 3/16" reamer and by ATS drill guide. Turned out excellent.

Marking the brake line holes in the bottom skin - 2 hours

 One of the items I noticed was quite right was the alignment of the holes in the gear weldment and the pilot hole in the bottom skin for the brake lines. They don't exactly line up as well as some of the other pre-drilled parts. I decided that I will open the holes so that they align. First job is that I need to mark the holes.

 I clecoed the bottom skin on and fitted the gear weldments.

One of the items you have to pay attention to is that the most forward hole in the bottom skin (that is a the center) gets drilled out to #12 for future U-720A on the tri-gear RV's. Since I am building the 7A...I need to do this. I'm reluctant at going the full #12 now, so I just opened the hole to #30 so I don't accidentally dimple/rivet it. 
 

Now that its all together you can see how the pilot holes line up. One is decent, and the other is a bit off. 

I scratched my head on how I was going to mark the correct location on the bottom skin. I finally came up with the idea of using a paper tube to diameter of the hole in the weldment. I dipped that paper tube in white paint which I was able to stick through the weldment hole and mark the bottom skin. It worked very well.

I will open the pilot holes up just a bit (not to the full 5/8" opening). Then once the fuselage is fitted together and the parts are in their final position, I will use the dremel and files to open up the holes in the skin perfectly centered.

 

Initial fitting of the Gear Weldments - 4 hours

 I managed a more productive day. I need to fit the WD-721 landing gear weldments to start drilling the pilot holes on the side skins. The fit seems to be really good. I reamed the mounting holes with the appropriate reamer. Some of the powder coating in the holes prevented the bolts from going through.

It took some time to get the bolts installed as there is a bit of a trick and process to it.

 Straight away I noticed that they is some interference with the bottom/forward cleco in F-704 as it interferes with the aft portion of the gear weldment.  

I marked the hole and I see that I am going to have to use a file and cut a relief for the future rivet shop head.

Once I was satisfied with a nice tight fit. I began drilling the pilot holes in the weldment/side skin. For now, I only drilled the main portion of the weldment to #40, and the forward support tube/flange is drilled to #30. I have decided I will open these holes up to the appropriate 3/16" holes later in the build where the instructions have you install the gear weldments. (With bulkhead F-902 installed it becomes extremely difficult to drill the holes in that forward flange, so I want to locate them now)

Satisfied with how things went. I completed the other side.