Horizontal Stabilizer Rear Spar

Started work on the horizontal stabilizer today. The first part involves preparing the rear spar.

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Deburred the rear spar and the rear spar doubler with the Scotch Brite wheel, files, a deburring tool and god old fashioned sandpaper. Got all the edges and lightening holes nice and smooth. Clecoed the rear spar doubler to the rear spar. Final drilled all the holes.

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Clecoed the 8  outboard hinge brackets to the spar and final drilled.

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Machine countersunk the two holes in the center of the spar.

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Fit, clecoed, drilled, disassembled, deburred, reassembled, and riveted the inboard hinge bracket assembly with the flange bearing in the middle.

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Deburred and scuffed everything. Ready for primer. I’m only going to prime the inside of the spar. the outside will be painted when I paint the airplane. I neglected to account for this when I built the VS and rudder. I’m assuming the primer can be stripped from the outside of those spars in preparation for painting.

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Today’s Time (hours): 2.5
Empennage Time (hours): 48.5
Total Time (hours): 48.5

 

Disassembled, Deburred, Dimpled

Deburred and dimpled the skins and substructure.

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Machine Countersunk the trailing edge wedge.

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Began back riveting the stiffeners into the skins but it’s loud and it got late so I quit until tomorrow.

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Today’s Time (hours): 3.0
Empennage Time (hours): 30.0
Total Time (hours): 30.0

 

One step forward, two steps back

Started off the day dimpling the vertical stabilizer skin with the DRDT-2. I’m pleased with this tool. Dimpling large parts like the skins is a piece of cake and the dimples are consistent. I will say that I am considering getting a c-frame as well. It would have come in handy for riveting the rear spar. Juggling the spar and the pneumatic squeezer was challenging. While the squeezer was workable, I think the c-frame would have been easier.

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Once the skins were complete, the fun began! I was dimpling the substructure when I decided that the VS-707 rib needed an extra hole. So I made one. With the pneumatic squeezer and dimple dies. I hammered out the unwanted dimple and made a doubler to fix the flange. I completed the rest of the dimpling uneventfully.

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I riveted the aft spar assembly together. This went well and I’m happy with the result.

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I riveted the front spar doubler to the front spar and clecoed the ribs to the front spar in preparation for riveting. And that’s when things went south again. I tried to rivet the root rib and the nose rib to the spar from the front of the spar to the back. Turns out that this is extremely difficult due to the angle of the nose rib. Even with an offset rivet set in the gun, I couldn’t get straight on the rivet. I tried to buck it anyway. The rivet folded over. The angle of the nose rib made drilling out the rivet problematic as well. I thought about drilling the shop head but it was too messed up to drill. I ended up mangling the hole beyond repair. Turned all three parts into scrap. I ordered replacements from Van’s and since I was already going through the process and paying for shipping I included a replacement VS-707 as well.

Lesson Learned: If it doesn’t seem right, stop and think about it. When I couldn’t get the rivet set square to the rivet, I should have stopped and considered shooting the rivet from the other side.

Today’s Time (hours): 6.5
Empennage Time (hours): 15.5
Total Time (hours): 15.5