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| Fuselage...upside down, nose in front, firewall at the rear |
Big day yesterday! The core of the fuselage started to take shape with the assembly of the fuselage sides and the 3 main bulkheads...the seatback, the instrument panel, and F22. It is really neat to now have something in the garage, I mean aircraft factory, that looks kinda like something you might get in. One day it may actually look like an airplane.
I did not follow the plans method of jigging the fuselage. Instead I used
Wayne Hicks method of jigging it upside down on the work table. I believe this was much easier than the plans version. The only difference for me from Wayne was that I had to cut a hole in the table to allow for the top of the IP to stick through. Wayne had used two doors and just slid them apart. My particleboard table top didn't come together in the right place so I just cut the hole. You can also simply add 2x4s on top and assemble on top of them but I thought it easier and more accurate just to cut the hole and replace the top when done.
This step only took about 2 hrs to accomplish but I spent at least 15 hrs preparing for it. You want to make sure everything is correct before the epoxy goes in because it will be heck to cut apart and fix after cure. I fit each bulkhead carefully making sure each one was true, square, and in the correct place. I had a little adjusting to do to each bulkhead but I was generally amazed how it all went together as planned.
Tip: I ran into the same problem many have in that the IP was about 1/4" too short in height). I thought this may have been an issue with the distorted M-drawings which is why I used the additional full size M-drawings but I guess the template is just off. It's an easy fix to add a little foam to the bottom (you did save those foam scraps didn't you?).
After initial fitting, I went back to each bulkhead and filled any gaps with foam for a nice tight fit. Then I went through and figured out how I was going to secure each bulkhead in place while it cured.
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| Jigged and secured for curing |
Finally, (
Tip) I disassembled the entire fuselage and rehearsed each step of how I would put it together when I actually put in the epoxy. I even wrote it down so I wouldn't miss anything. I wanted to make sure I knew exactly how I was going to do it so I didn't find myself in the middle, with epoxy on my hands, and run into a problem of some kind. After rehearsal, I took it all apart and did it for real. It all went very smooth. All the bulkheads are true and measurements are pretty much right on except the bottom (top in the picture) of the seatback. For some reason it's about .25" short horizontally. The seat itself measures properly per the template but when installed and aligned from the top longeron to the bottom longeron, it doesn't quite make it to the forward mark. Best I can tell, this shouldn't be an issue. Above is what it looked like while curing.
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| Screws through boards hold bulkheads in place to cure |
Like Wayne, I used dry wall screws and predrilled the holes through the fuselage sides. If your bulkheads fit well, this works great. I also put the screws through a 1x6 board on each side to aid in spreading the pressure across the entire area. The first two boards to the left in the pic (right) are holding the seatback and IP bulkheads. The front board is just holding the foam ends nice and straight with the F22 bulkhead.
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| Giant rubber bands holding F22 against the end |
You can also see the big rubber bands I used to help hold F22 nice and tight against the end. The top and bottom were screwed in to provide a solid hold but I wanted something to provide even pressure along the entire height of the bulkhead to make sure it stayed straight.
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| Location block for the IP |
Tip: I also added a location block to help position the IP. (right pic) . I did this because every time I put a screw in from the side to hold the IP in place, it would move on me. I didn't predrill the holes into the side of the bulkhead as I thought this might not allow the foam to hold the screw as tight. If I had, maybe the IP wouldn't have moved. Instead, I installed a location block on each side that I could move out of the way and then quickly position once the IP was installed. It starts from the forward position of the seatback and extends to where the front of the IP is supposed to be and has a screw at each end. I can easily remove the screw closest to the IP and swing the block out of the way to get the IP in place. With the top (bottom in the pic...remember it's upside down) up against this block, I knew it was in the correct place. I then squared it to 90 degrees, pinned the top with a small nail and then I could install the screws without it wandering on me. It worked great.
Time to go reinforce the joints and install the landing gear bulkheads. Onward.
cab
