December 15, 2019

Torque Tubes Part 3

Another 2 hours playing with torque tubes. I really don’t know what is the acceptable level of friction. It bugs me that the bushings rotate freely on the tube when it’s out of the fuselage, but the when I put the tube in and start clecoing down the close out ribs, it goes to crap. I saw that another builder got advice from TAF to wait until the side skins are on before attempting the torque tubes. I think there are a few more things I can try before moving on, per the photos below.

The right outside floor rib – I’m looking straight down in the photo, but you can see that the top of the rib (which the flap torque tube rests in) twists outward a bit (down in this photo), which in turn puts a twisting force on the bushing. The twist is being caused by stress from how the rib is riveted in, not that the rib is actually bent, so I think I might have to find a way to relieve that stress. Same idea as relieving the stresses on skins so as to avoid “oil canning”. Maybe use a fluting tool?
This left outside rib shows some of the same stress twisting, but the arrow also points to another defect (next photo)
It looks like this left outside rib also has a bend in the bushing channel that I need to smooth out

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