Chapter 11

Elevators

The foam elevator cores were difficult to cut, it seemed as if the temperature of the saw was always too high. Beverly and I ended up cutting a total of seven to get four usable cores. Some of the throw aways would have been acceptable, but I wanted them to be perfect.

I had ordered the jigs, and hinges from brocks earilier. But Wicks sent me enough thin walled tubing to build the torque tubes. But without a mill this wasn't an easy task. First I layed out the dimensions of windows on the tubes. Then I took my dremel with a cut off wheel and cut the square windows undersize in the tubes. Final shape was achieved with two files, one flat and the other round (for the corners of each pocket). During the filing process I continually checked the fit of the hinges, to make sure that I didn't go too far. Another cirtical area to be aware of is the centerline alignment of the hinges! After I accomplished this four times, I installed the hinges and checked the fit of the hinge pins (3/16 SS rod from Wicks). Everything fit great time to add some foam!

With the torque tubes complete I started putting the cores on them. Nat says to roll them on, but sliding ever so gingerly was easier for me. I was a bit sloppy with the micro and made a small bump, after I had sanded it flush I noticed I put a low area on one of the cores (so much for perfection). It was fairly small and I decided that it would be best to get it during finishing, than to risk making it too high with micro. Glassing the tops and bottoms was easy and quick. Now I just had to build the torque tube offsets. Later note: Changed my mind about building the offsets and ordered them.

After getting back to building the elevators(about 6 months later), I was ready to install the TT offsets. The 4130 steel is very hard to drill through, I used a little lightweight oil to lubricate the drill bits which helps a little. My handheld drill walked a little on the first hole making it slightly off center, but the bolt still had good grip so I left it alone. Aftering assembly it was time to mount them to the canard (wow a moving surface!).

I jigged the elevators using the jigs from the drawings, but my gap was next to nothing when they were jigged in place. After my panic attack, I looked up John Slade's website. He had the same problem, apparently the jigs set the elevators at 12.5 degrees down already so a small gap is okay here. When cutting the slots for the hinges in the canard, I noticed that I had to come right up to the the edge of the spar cap. After mounting I checked travel and there was 15 degrees down and 30+ up travel.

Doing the wingtips was interesting to say the least. While Nat gives a template for the rear of the wingtip, there isn't anything for what the front was supposed to look like, not even a drawing. I shaped them similarly, and glassed.

Elevators Jigged with offsets	Elevator mass balance installed
Going Up!	Coming down!
Canard Tip