Step 2. Contouring the bottom

Next step is to contour the bottom and the sides. First I will shape the bottom corners and glass the bottom. Then I will turn the fuselage and contour the top longerons and glass both sides.

The plans are rather weak in telling how the end-result of the next steps will be, so I read through all the builder-logs I found and collected pictures and descriptions of how other did it. Then I started…

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The first corner-cut is according to the plans a 45° cut into the lower longeron exposing 1/4″ inch of it. I drew a couple of help-lines on the bottom-foam and the side-foam and used my saber-saw instead of the jigsaw recommended in the plans. I also deliberately avoided to cut into the longeron. I will instead use my belt-sander to trim of the final millimeters. Using the saber-saw was a walk in the park. I’ve seen numerous blogs where the builders invents special-tools, jigs and whatever to do both these cuts and making router-jigs to shape the NACA-scoop using several HOURS on a task that just takes some minutes to do on freehand. These corner-cuts are not rocket-science. The main thing is to get both sides as symmetrical and esthetic pleasant as possible.
Bonus: Had to buy a new power-tool: The belt-sander. Didn’t have this in my collection!
Bonus2: Since I used Divinycell instead of the plans Last-a-Foam as spacer-material (the grey foam in the picture), cutting, sanding and shaping the countors was easy since both materials have the same density and properties.

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The rest of the cutting was done by hand with a hacksaw. An easy task which took only a couple of minutes. Then I used the beltsander and a sanding-board to do the last touch-up.

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Finished contouring the left lower side.

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A nice round shape. Hand-sanded the last bit to get a good round shape. Use the hand to feel if there are any bumps. Much easier to feel than to see!

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Around the landing brake I should sand down 1″ / 2″ wide and 1/16″ deep area. I chose to use my router instead.

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I used the same method around F22.

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On the sides and aft of the landing brake (which is temporary glued in place) I built up a 1/16″ high and 1″ wide strip of duct-tape. Took 6 plies to get it flush with the landing-brake. The reason for doing this is beeing explained in chapter 9 (at least that’s what the plans tell me)…
Hindsight: In chapter 9 I didn’t manage to “pop loose” the landing-brake, instead it broke loose destroying the brake. Maybe it’s a better way to do this step?

Antennas

I have read a lot about antennas and landed on the simple solution that has been used by many builders. I tried to contact RST Engineering as recommended by many, but they refused to ship the parts outside US (!). I ended up buying the stuff I needed from Aircraft Spruce (copper-tape and ferrite-torroids) and coax-cable locally.
The info needed is on Marc Zeitlin’s Cozy-website. I also gathered very useful information from Charles Furnweger’s website.

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I decided to add antennas for marker-beacon and glide-slope at the bottom of the fuselage. After measuring I used my router with a 5mm bit to route the channel for the coax-cable. I also routed space for the torroids.

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The coax-cable ends up just ahead of the instrument-panel. Remeber to make a transition between the hole and the cable-channel so the cable exits with a gentle radius. I drilled the hole pointing slightly forward as well.

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I routed space for the torroids. I had to carve out some more foam where the copper-tape meets the coax to get the soldered ends to be hidden inside the foam. I later filled the channel with wet micro to secure the cable and stuff.

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The soldering was easy, altough I had to remake the glide-slope antenna once since the copper-tape broke when I bent the wire too much. It’s delicate stuff. There are no need for recessing the copper-tape into the foam as it’s very thin.

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Finally – the antennas are in place. The next step is to fill the channel and depressions I made with some wet micro to ensure that the coax, torroids and soldered ends will stay in place and be protected. I also remembered to measure where the cut-outs for the wheel will be so that the routing of the cable avoids this.

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