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prkaye

Well Known Member
The aileron counterweight is that heavy pipe. A series of holes must be match-drilled with the aileron leading-edge skin. When drilling pipe for the tip ribs, I found that the drill bit has a real tendency to slip, or "walk" along the curved surface of the pipe. If drilling through a skin, this could lead to elongated holes in the skin. Question... should I:

a) mark all the holes through the skin with a sharpie, then remove the skin and then drill the pipe at the marked locations with the drill press?

b) drill through the holes in the skin but just use a cordless drill at low speed to get the holes started?

Also, does this pipe need to be primed? Somebody once mentioned to me that they thought it was "stainless steel" and didn't need to be primed.
 
Center Punch

I supported the pipe and LE skin on a 2x4 on edge and used a center punch to mark the rivet locations, then drilled them out on my drill press. The pipe isn't stainless but is galvanized. The manual says it doesn't need priming, but everybody seems to anyway, including me. Some even slosh primer inside the pipe.
 
I used the pilot holes in the skin and a #40 bit to create the starter holes in the pipe. No walking, no elongated holes. I then went back and drilled to #30 no problem. Easy as pie and no problems.

Used an old drill bit to make the countersinks, used the hammer and male die method to create the dimples. Worked great.

Primed with the same stuff and methods I have used for everything else.
 
WSBuilder said:
I supported the pipe and LE skin on a 2x4 on edge and used a center punch to mark the rivet locations, then drilled them out on my drill press. The pipe isn't stainless but is galvanized. The manual says it doesn't need priming, but everybody seems to anyway, including me. Some even slosh primer inside the pipe.
Click to expand...

The counter weight pipe in the 9's are stainless.

I did like you're asking, Phil. I marked with a sharpie, removed them from the skin and very carefully center punched them. Then set them in my drill vise and used the drill press. Very sharp bit, very slow speed, lubricate. All should work well.
 
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Did that task during the weekend.

1) Primed the Counter weight and skin (minimize scratches to the skin)
2) Clecoed assembly together
3) Partially drilled the counter weight and the skin with a #40 drill bit
4) Took aileron apart
5) Drilled the counter weight with a #40 drill bit then a #30 in a drill press
6) Used an old drill bit to countersink the counter weight
7) Primed countersunk holes
8) Dimpled the aileron skin with a male die and a hammer
9) Trial fit all pieces
10) I am currently waiting on a helper to rivet the ailerons together
 
Phil,
Just finished task (you and I are close in our -9A build). I have a center punch that is "automatic" - you compress the tip (spring) and a strike occurs. I did this 3 times on each hole, then used the 1/8" drill. No walking. An Irwin black oxide bit actually cut all holes in both tubes except 3 - excellent drill. All drilling with cordless set on slow. Used Boelube each hole.
Carl
 
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