After you test fit F-22 into the fuselage, you mark where the front seatback and the instrument panel go on the fuselage sides. I took a lot of time making sure both sides were marked accurately because it seemd like if I didn't I'd have lots of problems with future steps. You also drill holes in the sides for this step which will serve to locate nails into the IP and FSB when the whole thing is assembled. While this way seemed a little crude, it went together nicely.
Here is a picture of the fuselage assembly jig I built. My daughter Emily is "showing me how strong it is." I followed the plans, basically, but put in on legs so it sits off of the floor. I read on another builder's web site that doing some of the taping and other assembly steps is easier if this jig is off of the floor. I also put adjustable feet on it to make leveling easier later.
The adjustable feet made it really easy to level the jig - both in pitch...
I did, however, have to use my belt sander and grind a bevel on the horizontal members to accomodate the way the bottom of the fuselage is shaped.
I drilled some 2" holes in the temporary firewall to help clamp the bottom to the jig. I also made some plywood sqaures, inserted some blind nuts and then ran bolts through the blin d nuts to adjust the rear of the fuselage level in pitch and roll. Then I tightened the clamps I had passed through the holes I drilled and the whole assembly was ready for the next steps.
The adjustable feet on the jig made this part a whole lot easier. So, too, did my friend Tom's digital level (thanks, Tom!)
When it was time to flox the fuselage sides to the bulkheads and clamp it together, I made this high-tech !?! clamping system. The straps are designed for tying motorcycles onto a trailer, the boards came from Wicks as packing material! Worked great, though - I drilled holes through the boards to allow the nails Nat has you locate the bulkheads with to pass through. The second board over the area outside the front seatback keeps the board inside it from flexing and not applying pressure to the center of the seatback and bowing the fuselage side. Check things level, in pitch...
and in roll, turn off the lights, lock the door, and don't go in for 24 hours!
It didn't take too long to get the front seatback sanded to fit the side, but, I'm glad I did a thorough job there. Once the assembly was done, the fit was almost perfect. Shaped just right, no major gaps or places where it was too wide.
Here's a shot of the other side of the front seatback after making the flox fillet post joining the whole assembly together. The assembly part of this went pretty well, but, I spent about 3 hours making flox fillets and cleaning up flox drips. I was exhausted - climbing in and around the fuselage, making sure I had good flox joints but scraping away the excess and making fillets tired me out.
I like the idea of doing my fiberglass tapes between two layers of waxed paper, but, I do mine a little different. I make a sort of template on the bottom piece of waxed paper - enough width and length (measuring all the areas I need taped and adding some length just in case) to make all the tapes I need. I then lay on my fiberglass, wet it out, squeegee etc. and once it's pretty much done lay on the top layer of waxed paper. I then squeegee some more making sure the layup is bubble-free but not too dry. I then cut the widths and lengths I need, while the waxed paper is still on both sides. As I start doing my taping, I peel the waxed paper off of one side and apply the tape where needed. The waxed paper keeps the tape from stretching and keeps the mess down a bit. Once that tape is in place, de-bubbled and trimmed as needed I do the next tape, starting by removing waxed paper from one side.
F28 was a little tricky to install. In this picture I've got a piece of wood clamped to the front of it, the obligatory nails through it holding it from falling and in some respects to the wood block and the flox curing. You can see the rough spot where I sanded - boy 36 grit really kills your fingers.
Here's a larger image of F28 clamped in place for the flox to cure. I used some small plywood pieces to keep the clamp from damaging the foam.
Here's a shot of F28 after the BID tapes are installed & after the flox.
Whew! Made it! After four attempts and two different parts I finally got this thing installed! You're probably wondering why I have so many pictures of a simple part and a simple install - probably because I screwed it up so many times! Done! Finally!
Here's a shot of the aft landing gear bulkhead being installed. I used clamps to hold the bulkhead against the block they had you install to get the 5" spacing away from the firewall. I also used a couple blocks under it to make sure it couldn't slip down while curing. If you're still building any of these bulkheads - don't final sand them to shape until you install them in the fuselage. That way, you can ensure a perfect fit. Note how Iabeled my bulkead so I'd install it right. You really can't tell without looking closely which side it the front and which is the back - I didn't want to install it wrong.
This shot shows the forward, upper landing gear bulkhead after being floxed in place. I work very hard in parts like this to get a nice, smooth flox fillet. This seems to help greatly in getting the fiberglass tape, inevitably applied in the next step, to lay down smoothly and avoid bubbles. I use the end of those mixing sticks for forming the fillet - it's about the right radius.
After the lower section of the forward landing gear bulkhead is installed, the upper section is installed. The plans don't say to fiberglass tape these parts, and, their was some discussion among the Cozy builders as to whether or not these were needed. Many builders described "there's so many layers there" referring to the layers of 'glass that are applied in later steps, that they couldn't tell if they did these or not. I did them. Just to be sure. Can't add 'em later...
The forward face of the forward landing gear bulkhead gets 3 layers of UNI, the aft face gets 6. I had a hard time getting the bubbles out from under these layups (they're made on the jig table, using a template) after they were transferred from the workbench to the bulkheads. A heat gun helped quite a bit, though.
This is pretty well documented in the archives, but, I didn't get it. Make your electrical channels as low as possible, and, as large as possible. That way, you'll have plenty of room to pass all the wires from all that high-tech gear you'll put in your instrument panel and you'll have plenty of clearance between the top of the channel and the bolt heads that hold the flight control pulleys on the firewall. I ended up cutting out the top (as viewed here) corner of the last 2 or so inches of the channel and adding a 3/4" wide piece of wetted out fiberglass. Thus, my channel, as it travels aft, gets taller as it reaches the firewall.
Like the plans had you do for the forward landing gear bulkhead (lower piece) I made a jig to separate the lower firewall 5" from the aft landing gear bulkhead. After sanding and adjusting the holes in the firewall for about a day or two, it was easy to flox in place against this jig using a couple clamps to hold it.
