Fuselage Assembly

Finally, 3D!  In this chapter you make a fuselage assembly jig, assemble true and square, and end with attaching the bottom foam to the fuselage.

• Step 1 - Assembly of the Fuselage Sides
• Step 2 - Center Keel and Seatback Brace
• Step 3 - Contouring and Installing the Fuselage Bottom

Step 1 - Assembly of the Fuselage Sides

August, September, October 2006 - I don't know what it was, but I over-thought how to begin this chapter.  Finally getting off my dime, I decided to follow the plans (imagine that!).  There are a lot of people following Wayne Hick's upside down technique, which has just about become some sort of standard.  However, after asking a handful of builders what they thought and thinking it through myself, I saw no real benefit.  In fact, I am very happy I didn't do it upside down, and here's why:

1. Wayne assemble upside down, on a door.  I didn't have a door.
2. Wayne cut his table top (the door) to fit the instrument panel (remember, upside down).  I didn't want to cut anything.
3. The plans way has the longerons on top, which are supposed to be perfectly flat.  I found it VERY EASY AND CONVENIENT to be able to lay my level in various positions to verify I had everything set right.
4. The last thing I need when reading these plans is to have to flip measurements in my head.  It was a beautiful thing seeing the fuselage come together as it will eventually sit -- right-side up.

All things considered, there's no real issue with the plans method -- it works as-is, and quite well.  This is not to take anything away from Wayne, who does fantastic work and has been very helpful to me whenever I've been fortunate enough to visit his project.  He's definitely going to produce a fine airplane.

October 15, 2006 - I actually did make a slight change to the plans approach.  The plans call for a 10' 2"x10" "plank".  I was worried about warping, and what a 10' plank would do once its warping gear got in motion.  I was imagining my fuselage twisting up like the Wright Brother's wing warping setup.  So all I did was to by a 6" wide board instead of a 10" wide board.  The purpose of the board is only to establish the length of the jig, and to allow securing of the lateral 2x4 boards.  In reality, you only need a 10' 2x4.

Here's how I secured the jigs so they wouldn't move -- with that magic Bondo stuff.

I managed to test-fit the seatback and instrument panel, and reluctantly put a couple screws through the sides and bulkheads.  I checked level and setup for the "wet assembly" as best I could.  I ran out of gas after several hours of this, so floxing and taping will have to wait until... tomorrow night?

October 16, 2006 - I prepared the seatback and instrument panel bulkheads for taping, but only got to floxing tonight.

October 17, 2006 - The plastic tent with small electric heater on low worked well to allow a 20-hour cure.  I sanded all the flox bumps away, and was even able to use those Permagrit bits in my Dremel.  It was a piece of cake to clean up my not-so-clean floxing job with those bits.  I floxed F22 and reworked the fillets for the seatback and instrument panel bulkheads.  I think the BID taping comes next, which I can do in multiple sessions.

October 18-19, 2006 - BID taping did indeed come next, which wasn't difficult.  Chrissi (Cozy Girrrl) put it in my head to use aluminum foil instead of plastic, but I chose to use the 6mil plastic to prepare the 2"x__" tape strips.  They were quite easy to use, and I appreciated the bendable and translucent "features".  Next up... mounting the landing gear bulkheads I think. 

October 23-28, 2006 - I took an entire weekend off for family fun, but spent the next several sessions cleaning up from the prior night's work, readying remaining areas for taping (sanding), taping... (repeat).  The fuse is coming together, with the landing gear bulkheads being all that's left before moving to the floor.

November 18, 2006 - I finally got enough confidence to mount my aft landing gear bulkhead.

I didn't like the plans method of jigging here using hot-glued blocks, and so I made 5" blocks and clamped between the firewall as tight as I needed.  The clamps in the middle of the picture on the left are supporting the weight of the bulkhead, even though it fit rather snug.  I checked for level and plumb and threw some plastic over it and turned on a small heater.

November 20, 2006 - I made my upper LG bulkhead too narrow, and so I'm cutting in half, inserting some extra foam, and re-glassing.  The stresses in the middle of these bulkheads are only supporting a small amount of tension/compression.  Aside from being annoyed by the extra weight, I'm not worried about this repair.

A question I have in this area is that the top edge of the forward LG bulkhead is above the stringer on the left (see 2nd picture).  This issue can likely be traced back to the LWX/LWY stringer section in Chapter 5, where my length of the diagonal stringer was a touch short.  The plans say to cut this down, but there are many stories of builders who have trouble fitting the landing gear in this area anyway.  I don't want to cut it down. 

The plans have you fit the upper LG bulkhead flush to the inside of the stringer, but it happens to fit perfectly above the stringer, mating perfectly with the top edge of the bulkhead.  Given that I want to keep the height of my forward LG bulkhead per plans, I am planning to install the upper LG bulkhead above the stringer.  There's a Canard Zone discussion on the topic here.