Flap & Main Elevator Torque Tube (Finally Smooth)

After we had drilled out all the brackets around the flap and elevator torque tubes (because they had too much friction) we started with sanding down the inside of the bushes and the brackets where the bushes were held in place. The theory was that the friction was caused mainly by two things:

1. Not all bushes were exactly lining up at the same height
2. The brackets clamped the bushes such that they slightly deformed

We found out that the bushes that turned inside their bracket (when turning the torque tube) were the ones that were "too low" and that the bushes that didn't turn inside their bracket were the ones that were "too high". So we knew that we had to sand down the brackets of the bushes that did not turn because those were the high spots, in order to get all the bushes to line up. This combined with sanding the bushes with a fine grid sandpaper and using a bit of dry lube on the torque tube helped quite significantly.

With sanding the brackets down we had to be careful not to enlarge the holes too much because that would cause the bush to turn in the bracket which is of course undesirable regarding wear. With sanding the bushes we had to be careful as well as not to cause too much play between the tube and the bush.

A link to a video showing the final result will be added to this post. Also, one of our supervisors Jack inspected the torque tubes and he was satisfied with the amount of friction.

Builders:

• Niels
• Pepijn
• Suzanne
• Tetsuo