Cornell Rewinged

The other day was crazy windy. We flew only a couple flights, and they were a lot of work against a heavy cross wind with 10 mph winds and 20 mph gusts Stupid fun flying. So it was a great time to take my Eflite PT-10 Cornell up! Kenny Chandler, the only other flying fool, asked me why I hated the Cornell... then as I headed out to the flightline crabbed his camera and said he just had to film this!  (Here's your sign... but I was being bold!). Touchy cross wind takeoff in a plane that begs to roll the upwind wing, flying 45 degrees to the wind to run down the center line, kiting around turns near the tree line. There's always a nice burble on windy days along the tree line at the south end, and I flew into it. She rolled the wing nearest the tree line down hard, I compensated, she did it again, I over compensated... a nice pilot induced oscillation, tip stall, POWER, stall, crashes onto her wing. But it was a WILD ride!

Yesterday I redid the wing, and today the cote. Getting the cote right was tough as I learned how to use the heat gun (LOVE the heat gun for cote, but there is a very very thin line between shrink and melt...). I decided to redo the cote on the vertical stab... that was a pain in the ass and I redid it 3-4 times. The left side still isn't right, and I was too tired to take any pics... the wing came out pretty good though!

Pre-repair with the cote removed, underside right wing. The wing is broken clean through aft, a couple ribs and the leading edge spar, held together here by the top cote. I carefully peeled the S of U.S. off and would replace it later. 

Repaired the ribs and spars. The wheel box was shattered, though you can't tell from the pre pic. I had to remove the sheet balsa, reconstruct the box with the existing parts, build a new roof under it and then re-sheet the balsa. In rebuilding the cracked spars I used the technique below to add supporting wood behind existing structure.

I use popsicle stick wood, Dremel sand some arcs to reduce weight.

The wheel box is re-sheeted.

And the underside cote is done nice, clean and snug, using my newly developing heat gun skills. I did the underside easily, but the topside took a couple tries. I also put the S back on and made new periods.

But it too came out near perfect.

The dihedral is spot on, no new twists that I can see. The new wheel box is sturdy.

She looks great, though I wish the left side of the vert stab cote looked better... next time.

No pics, but I decided to change the motor. I had a HURC 2836-09 driving a 10x8 Master Airscrew powered by 3S 3300. I think this was a marginal power setup. I decided to change to a HURC Power Up 450 motor Kenny Chandler had given me. for a few more kv and 50 more watts of power without any more weight up front (remember she has the metal motor mount, so front end weight is an issue). I think she will fly a tad better, and can even handle a 4S if I want to. Hoping to fly her tomorrow!

UPDATE (1/1/12): Went back this morning and redid the left side of the vert stab, and it came out wonderfully. I also took a moment to strengthen the structure of the frame, which you can see through the cote in the pic of the right side.