Today I worked on getting the rudder torque tube assembly put back together properly. I didn't get a photo of them, but the inner torque tubes were in quite a state. It appeared that the first builder adjusted fitment of the outer tubes by scraping the powder coat on the inner tubes. It was anything but smooth, and before I disassembled them they were very difficult to move. The copilot side was so stiff that it could actually hold position against the return springs.

So, I had some work to do. I started by sanding the powder coat on the inner tubes axially until I achieved a smooth surface that allowed the larger outer tubes to slide on easily.

This also required smoothing the inside bore of the large outer tubes. I found a suitable length of aluminum rod in the servo mounting kit, wrapped some 220 grit around it, chucked it in the drill press and went to work removing quite a bit of powder coat overspray from inside the tube.

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I then started work on fitting the bearings. I ordered new bearings from Kitfox because the originals were in very poor condition. The build manual says to cut them so you can get them over the tube, but I didn't really see the point since they slid on from the end with a little bit of twisting. I fine-tuned the powder coat on the inner tubes until the bearings spun smoothly with light fingertip pressure, then tried the whole assembly to check for smooth rotation. It took several iterations of sanding, assembly, testing, disassembly, sanding, etc., but I got a nice buttery action on both sides.

One of the outer tubes had a very slight bend to it. I'm not sure if it was like this from the factory, or if it happened during welding. Fortunately the bend was so slight that I was able to get it to fit nicely by sanding powder coat on opposite sides at each end.

During all of this work I discovered that the new bearings have a thicker flange than the originals from 1995.

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This meant that not only did I not have the required 1/32" of play on the large outer tubes, I couldn't even get the rivet holes to line up. So, I went after the bearing flanges with some 120 grit on a piece of plywood. More sand, assemble, test, disassemble, sand...

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In the end I got a very nice fit-up on both sides, with no resistance to rotation with the assemblies clecoed together. I wish the parts looked better, but overall I'm very happy with the result.

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I'll be in town tomorrow, so I'll grab a tub of grease for the bearings, then I'll be able to pull my first rivet in anger!