Chapter 18 - Section 16

Installing the Fuselage Top

 

The work in this section is to secure the removable forward deck onto the fuselage. The forward deck is to be held by the two 17" side hinges (Section 14) and a 5 bolts/nut plate at the front flange to F28. Like many Cozy builders, I did not care for the nut plate mounting approach because one has to remove the canard to gain access to remove the bolts (Fig. 68). To me, that does not make a very 'removable' forward deck...

 

Front Hinge for the Forward Deck (Not to Plan)

I searched through the archives to see if there were any words of wisdom and found Brian DeFord's front hinge attachment approach. It looks like a good alternative, so I decided to follow, but with some deviation...In doing so, I by-passed most of section 16. Here's what I did...

 

I cut up a 4" section of the same hinge I used for the sides, then separated the 2 halves. I marked a center line at the forward face of the forward deck and notched out a small slot (both glass & foam) such that I can butt the hinge into the foam while flush with the forward face.   

 

I have to trim the hinge half a bit narrower such that the hinge eyelets protrude just above the bottom edge of the forward deck. I also drilled 4 1/8" diameter holes through the hinge face to provide added anchoring (of the hinge) when I add flox to both sides of the hinge.

 

 

 

 

 

 

 

 

 

 

Next, I dug out the foam surfaces and made flox corners on the forward face of the forward deck - from end to end. I glassed the hinge, forward face and overhang with 2 BID layers, then trimmed after cure (picture left). 

 

 

 

 

 

 

 

 

 

 

 

 

 

With the forward deck back in place (side hinges and the 4 alignment pins) plus the bottom half of the forward hinge attached, I floxed the bottom hinge half in place. Once cured, I removed the forward deck, packed in some more wet flox, glassed the hinge half with 2 layers of BID and let cure.

 

Once cured, I carefully put in 3 more blind rivets to secure the hinge half. I was very careful not to drill through F28 when mounting the rivets. I have to order the shortest blind rivets (1/4" long & 1/8" diameter) from McMaster-Carr. Next, I cut up a short hinge pin with a 90o elbow and slid it right in. Access to the hinge pin was not a problem because it is right at the bottom edge of the forward deck.

 

 

 

 

 

 

 

 

To keep the hinge pin in place such that it will not slide out unexpectedly, I installed a short pin in its path (left). The pin is long enough that I have to 'swing' the hinge pin elbow up ~45o before I can pull it out. Just a simple safety measure added.

 

I am happy to report that the 3 hinge method works very well. All the hinge rods slide in and out smoothly and effortlessly. Once the hinge rods are inserted, there is no slop within the forward deck.

 

 

 

 

 

Riveting Side Hinges

I floxed the side hinges to the bottom of the forward deck earlier in Section 15. I did not add the rivets until now because the blind rivets called out in the plans were a bit too long and I did not have any shorter ones. I used the same rivets as above. They worked out OK.

 

[Hindsight] After I added the rivets, I experienced some sliding resistance/stiffness with the left hinge rod. I think the rivets might have pulled the hinge in/out slightly, causing a bit of tightness. Wiping the hinge rod with a bit of lubricant helped me regain most of the smoothness.

 

[Hindsight] A few days later and upon further investigation, I found that part of a rivet was sitting right on top edge of F28. I sanded the top edge of the F28 just a little bit, and all is well again...