Fuselage - Cabin

2007-09-08 - Fabricate F-795 flap push rods. (4.0 Hrs).

Wasted a few hours trying to figure out what to use to make the F-795 flap push rods. I have 3 pieces of AT6-058-xxx tube, 4", 9", and 18". I need two 4 7/8" pieces. The 4" pieces are too short, the 9" piece will only give me 1 rod, and the 18" piece is marked F-447. Problem is, I could not find F-447 anywhere in the fuselage chapter, and there's not much left to build on the fuselage.

I was going to cut out two loops in the middle of the flap hindges, but, yesterday, on VAF, I found this tip that really works. The rod will go in about 3/4 of the way, then it becomes too hard to push without using vice grips. However, if you chuck the rod in a drill, it will spin right in.
Now, we can fit the flap push rod.
For the right push rod, I cut a 4 7/8" piece off the 9" piece of AT6-058x9. That leaves a 4" piece that is too short for the left push rod. I'll have to use F-447, or order some more tubing.
This ain't gonna fit, what to do?
No problem, there's a hole in the table. Here, I have a smaller drill to insure that the tube is aligned.

BTW, tomorrow I will figure out that using the drill press to drill these push rods is a total waste of time, but carry on for now.

Not perfect, but good enough (there's a discussion about this on VAF). BTW, the piece of wood is because the bottom of the vise jaw juts in, and I bent the tube the first time I tried to tighten the vise.
Dang! Down to the last few threads, and I ruined the cut. So, what happened? I thought I might have not drilled the hole deep enough, but I did. I spent a half hour tapping this rod. I backed out and cleaned the threads every few turns, but the last few theads were pretty tight. Van says to drill this to #3, but my tap table said to use 7/32" for a 1/4-28 tap. So, I thought maybe the hole was too tight.

Edit 8/9/07: tomorrow I will figure out that #3 is the correct drill.

The second hole on the other end came out the same as the first. This time, I drilled the hole using a 7/32" drill, and the hole was plenty deep. The problem may be that the tap is not perfectly parallel to the hole, not quite sure.
This just ain't gonna cut it. I've always said that you need to learn some skills to build an airplane, and tapping a hole is just one of them. If I can't get this right, I shouldn't be building. Funny thing, is that I did learn how to tap a hole in the Air Force, and I never had this kind of problem. Of course, that was quite a few years ago.