Rudder Skin Not Taut

[justplanecrazy]

I?ll attempt to describe my dilemma here as best I can.

The rudder skin stiffeners have been trimmed, deburred, dimpled, primed and riveted to the L and R rudder skins. The rudder skeleton has been clecoed together and I have clecoed the skins to the skeleton for match drilling. The skeleton is 100% clecoed hence is very stiff and the skin has been clecoed every second hole around the entire skin.

On the R rudder skin only, what I will call the skin sub panel (area of the skin between each of the skin stiffeners) pops in and out if you touch one panel and then the next panel up etc. To me, this seems like a classic for fatigue in service due to fluttering of the skin, especially on a control surface which I am sure will lead to control feedback to the stick.

I have done a bit of searching of the forums here and found a few issues in regards to rudder skin cracking however nothing that relates to the issue described here.

Has anyone experienced this issue with their skins and has it caused any problems or can someone suggest a remedy that they have used.

Thanks in advance.

Rob

[designerX]

If you search under the term 'oil canning' you will find some threads. What you describe sounds like 'oil canning' and I've read that many RVs have this effect on the rudder. The severity of this effect will probably be the deciding factor on whether you build on and fly with this rudder or order a new one.

I hope you get many more responses/replies. Can you more accurately describe the amount of movement and on how many 'panels' this issue exists.

The amount of movement will probably decrease when you rivet everything together. Before you do so.. make sure that your brake/bending device is perfectly straight and the trailing edge has been bent fully (down to the recommended minimum) and evenly.

Stan

[scard]

Mine oil cans just a bit in various places. I have to imagine that when under side load (deflected), the side in compression oil cans a lot. Looks like just a simple fact with the design. I also imagine that "fatigue" due to to the looseness of the skin will show up well before a failure, allowing the full day or two it will take to build a new rudder .