Fuselage Assembly (3)

 Not a lot of exciting things to show at this stage.  I'm just continuing to rivet the side skins in place.  I finished most of the areas I could easily reach in the forward fuselage section.  I'll finish the other holes when I flip things back over (although a lot of the upper holes will stay open until the top skin is attached.

I figured attaching the center floor stiffeners to the firewall and bulkhead brackets would be easier before the bottom skin goes on, so I did those next.

The right floor stiffener gave me some trouble where it attaches to the bracket on the bulkhead.  It is extremely tight in there, especially with a bolt head in the way.  I got the left stiffener in place okay, but I tipped the rear rivet over pretty bad on the right side, so I had to drill it out to try again.  The only thing harder than getting a rivet gun in place for that rivet was getting a drill bit centered on the rivet to drill it out. I had to use a 12" drill bit that I flexed to get it into position.  Long story short, it didn't work all that well.  I got the rivet out, but I enlarged the hole way too much in the process.  I decided to just upsize the hole to 3/16" for a bolt instead of trying to figure out how I could make it work with a rivet.  The bolt is overkill of course, but it's the common solution that Van's provides in cases like this.  This whole area will get a cover that goes over it since all of the fuel and brake lines route through the area, so it'll eventually be covered and forgotten about.

The last rivets to do in the forward section were the universal head rivets around the spar/bulkhead opening.  While I was there, I also drilled a 5/8" pass through for pitot/AOA lines.  I only need that on the side with the pitot, but I drilled the same hole in both sides of the plane so I could use it as a wiring route in the other wing.  I may have to drill a second hole in the left side since there are two tubes - one for pitot and one for AOA.  I'm not sure if they'll both fit through one hole or not, so I may have to separate them and drill another hole.

I started putting the bottom skin back in place to get ready for that riveting.  It's easier said than done to get that skin lined up!  There are a lot of stiff layers to deal with.  I'll have to convince Rose to help with some back riveting for most of what remains.  I won't be able to reach the rest by myself.  I need to rivet the forward bottom skin to the firewall, stiffeners, side skins and seat area bulkhead.  Then there are some remaining rivets for the seat ribs to side skin, and the baggage compartment bulkheads and bottom skin connection.  Lastly, the center section riveting to the tailcone.  I'll have Rose help with everything I can't reach when I roll the fuselage over, then I'll finish up with things like the armrests and all of the upper sections that are easily done alone once things are upright.

Fuselage Assembly (2)

I continued working on riveting the side skins today.  On the right side I got done with the main bulkhead skin rivets, as well as most of the other forward fuselage pieces.  I still have to do the larger 4- rivets for the gear attach web..  I am going to wait and do the rivets at the bottom portions and the main longeron until I flip the fuselage over.

 

The left side is a little behind the right.  I still have the vertical  902 bulkhead rivets and gear attach web to do.

Fuselage Assembly

I took care of a few odds and ends today before starting to put the fuselage back together.  I still needed to drill the top two engine mount bolt holes in the firewall.  I didn't drill to the final size, but punched trough the aluminum angle and firewall using the pre-drilled holes in the corner brackets.  I'll final size it all once it's time to attach the engine mount.  It's important that the holes through the bracket and into the firewall exit where they're supposed to, so I used a block of wood with a pilot hole in it to ensure I drilled perpendicular to the surface.

I had to scratch my head a bit to figure out how to get the center section off the floor and into position by myself.  Thankfully it's not really all that heavy, just awkward. I set the aft portion of the center section bottom skin onto the tailcone and wiggled the saw horse into position to support the front bulkhead.

There are a few things I skipped over while initially putting the fuselage pieces together because parts were backordered at the time.  One of those items was making the flap control support blocks.  Van's provides two "square" (hardly) blocks to make these out of.  It's the same approach as for the rudder pedal assembly - just plastic blocks on each side of the fuselage behind the seats to hold the control rod in place.  I measured and marked the blocks and used a 1" forstner bit to make the main hole.  I put the blocks in place and marked where the bolt holes should be to match up to the bulkhead holes, then I drilled those on the drill press.  These blocks don't get attached until after the skin is in place, so knowing they fit, I pulled them off and set them aside.

Time for the side skins and firewall to go back on!  Things definitely fit together a lot easier than they did the first time I put it all together.  I sprayed some rattle can primer on the skins where they overlap (already have good primer on the inside surfaces, so was just putting some on the outside of the overlapped portions)

I scratched my head a lot trying to figure out what the appropriate order would be for riveting.  I should be able to do a lot of it myself, but once I get to the bottom front skin, I'll have to enlist Rose to help.  Van's gives no guidance on how to proceed, except to say to rivet it all together and then flip the fuselage right side up.  I will probably take a slightly different approach. I'll rivet as much as I can by reaching over the top of the side skin, but it doesn't make sense to contort myself to rivet the bottom portions.  I think once I rivet what I can easily reach, then I'll flip the fuselage over and finish riveting things to the side skins with it right side up.  It's just easier to reach over vs lay or sit on the ground and reach up.

I bolted the bottom longerons to the engine mount bracket and torqued them down.

Last up for the day was actual riveting.  Because of how all of the pieces have to go together, it's not quite as straight forward as just riveting an entire piece to the skins - sometimes it's half of a stiffener, then you have to add another piece for additional layers, then continue riveting.

Fuselage Prep & Riveting

I continued dimpling skins today.  I finished up with both side skins as well as the forward bottom skin.  I made sure to tape off holes that shouldn't be dimpled.  It's far to easy to get rolling and accidentally dimple something that shouldn't be.

The F-904H center section side plate has to be pre-riveted to the side skin due to the fact that some of the rivets won't be accessible after the skin is in place.

As I was dimpling the forward rows of holes in the tailcone (where the center section connects) I realized that I had never riveted the piece of angle to the vertical bellcrank rib, and the rib had yet to be match drilled and riveted to the 706 bulkhead.  Way back when these parts were first put together, the instructions specifically said not to rivet them yet.  I still haven't really figured out why, except for the fact that leaving them clecoed makes it a little easier to get at all of the holes for dimpling.  Regardless, I figured now was as good of a time as any to rivet it all together.  I removed the vertical angle so I could drill and rivet the rib to the bulkhead.

Once the rib was riveted in place, I riveted the angle to it.

With that, I think all of the parts are ready for assembly again!  I'm sure I'll find some here or there where I missed something.  It was a real brain teaser to think through how each piece was connected and figure out the right prep for riveting.  I slid the longerons into the tailcone and clecoed them into place with just a few clecos.  Each longeron has 6 rivets that go in to hold it all together.  The rest of the longeron rivets are left out because they won't be installed until the top skins go on.

The last thing I did today was finish riveting the side skins of the tailcone, all of the way up to the longeron.  It was nice to be back to actual construction.  Next up will be flipping the tailcone upside down again and getting the center section and firewall attached permanently.