Rigging and floxing the fuselage

Chapter 6 is VERY exciting! You finally get a chance to go from "2D" parts to an actual 3D fuselage! ::caution - try to NOT blow a gasket when people ask, "Oh, cool! Are you building a canoe?!" I wanted to punch my neighbor in the face! Kidding!! Ok, let's get back to business...

First thing I did was dry fit everything. I started out by fitting the firewall onto the left fuselage wall... then stood it upright, then installed the right fuselage wall. This held the fuselage upright on its own.

I then loosely fitted the clamping device (threaded rod with 2"x1" pieces of wood) on the fwd section. I positioned the rear seat, then front seat, and finally the instrument panel, tightening the clamping device more and more as I installed each bulkhead.

Here is a close-up of the 'clamp device'. I made three of them. It's made out of two 3-foot threaded rod (1/4" DIA) and two pieces of 2"x1" wood strips (the wood is actually the strips that came with the shipment of the foam boards! Trying to save $$$). Each threaded rod end gets a flat washer, a lock washer and a nut - so you need 12 of each.



For the F22 bulkhead, I measured 4.1" from the top of the top longeron to the top of the F22 doubler. The waterline of the top of the top longeron is 23.0, the waterline of the top of the doubler is 18.9... hence the 4.1" measurement (23.0 - 18.9 = 4.1).

 I used the clamp to sandwich the fuselage sides onto the F22 doubler to hold it in place. After I had it where I wanted (using the 4.1" measurement), I predrilled into the top and lower longerons and inserted a fine thread screw. Also, I made sure the outside of the fuselage lined up with the outside line of the F22 side.

And there it was... the fuselage all built up for the first time. I proceeded to play around with it, moved a few parts, making sure everything was squared and level. I then used a marker to identify where everything needed to fit when it came time to flox everything in place.

 I took everything apart and prepped my bench table. I started out by making sure the table itself was level. Right on center!

After prepping everything for bonding (sanding every surface area that was going to be mated), I started by dry installing (no flox) the F22 bulkhead (since the screws served as perfect positioning pins). Notice how the fuselage is upside-down; this is to make sure the top longerons are level and parallel to each other - hence why you want a perfectly level workbench!

I then made sure it was square. This only works if you set the width of the aft fuselage section the same as the fwd section.

 I then made sure the left and right lines of the front seat bulkhead aligned. Perfection!

Unlike the plans, I inserted nails on the lower line so that the seat would rest on them (instead of having them go through and into the front seat sides as the plans indicate). This is so that I could slide the front seat into place more easily.

Here I am test fitting it.

 Notice how the nails hold the seat in place.

 It was time to flox the seat in place. Here I am making the typical "icing on the cake" trick with a ziplock bag.

 I applied a strip of flox along the fuselage sides where the bulkhead mating surfaces were.

 I then slightly opened the fuselage sides, slid the front seat into position, and then clamped the fuselage sides down.

Notice how the mark lines on the longerons line up with the lines on the front seat. These marks were made when I dry fitted everything previously.

Here I am verifying that the bottom of the front seat (remember, the fuselage is upside-down) did not protrude beyond the longerons.

Here I am verifying that the top of the front seat (remember, the fuselage is upside-down) did not protrude beyond the longerons. I stuck a 2x4 in there to verify the gap distance.

Once the front seat was where it needed to be and clamped down tight, I moved on to install the rear seat. I started out by applying flox to one side and screwed it into position (I had previously match-drilled holes into the LWX pieces when I dry fitted everything).

With the rear seat being held on by one side only, I applied a clamp onto the aft section of the fuselage and began to tighten it until the screw holes from the other side lined up with the holes on the LWX piece. I then applied flox to the other side of the rear seat and screwed it into position.

The rear seat was now fully installed.

Notice how the top of the rear seat (again, remember that the fuselage is upside-down on my bench) is aligned such that the edge does not exceed the LWX upper limit. The center section spar later crosses through there so you want to make sure you are clear of it!) 

 Now that the rear seat was floxed in place, I dry fitted the firewall on one side. The plan here was to move the clamp farther aft, and tighten it down until the longerons were the exact width apart to allow for the firewall installation.

Notice the wrench on the lower left... I kept tightening it until the longeron fell into position.

 Once I had the clamp holding the fuselage aft end to the proper width, I removed the firewall and applied flox.

 Notice how the upper portion of the fuselage does not get floxed to the firewall (since this area will be cut off later to allow for the center section spar to slide across and be installed).

After installing the firewall, verify it is 90 degrees with the top longerons. If you trimmed the aft portion of your fuselage walls properly, this pretty much happens naturally on its own and no shimming is required.

I put clamps on the longeron ends to hold the firewall in place while it cured.

Just to recap - the F22 bulkhead was dry-installed to hold the fuselage sides in place. The front seat was floxed in place, then the rear seat, and lastly, the firewall. Moving on, I came around to the fwd section of the fuselage.

I started out by removing the F22 bulkhead that was temporarily held in place with screws. I dry fitted the instrument panel and added another clamp to hold it in place. I pushed the instrument panel slightly aft of the installation line to allow for me to apply flox.

A bead of flox applied to both sides...

I then opened the clamp up a bit, slid the instrument panel into position, and began to tighten the clamp back down as to sandwich the instrument panel in place.

Here I am making sure the instrument panel was at its appropriate height by looking at the gap between the instrument panel and the 2x4. For some reason, the gap looks a lot bigger in the picture than it is in real life (in reality it's less than 1/8"). That's ok... it will be floxed in place to the fuselage floor later on.

 Now it came time to install the F22. I started out by applying flox to one side and screwing the F22 in place.

I then applied flox to the other side, and began to tighten the clamp until the screw holes on the F22 bulkhead aligned with the holes on the longerons.

 Here I am making incremental turns with the wrench (notice the wrench on the lower right) and checking alignment every few turns.

 Finally, the holes aligned and everything looked great!

 See... perfect alignment at the top longeron...

 And perfect alignment at the bottom longeron...

The F22 was then screwed into place.

 And there you have it... all bulkheads (except for the F28 bulkhead which is installed later) are installed. The plans say to apply BID tapes now. But after 6 hours in the garage... it was time to call it a day. This later caused a little bit more of work since I had to go back and re-sand the mating surfaces.