Stiffeners question on rudder

[JurgenRoeland]

I noticed that in almost all pictures I see on other builders websites, the rudder skin used to come bend in one piece of aluminum.
In the new kits for rv7, the skins come in two seperate sides which are put together with a trailing AEX wedge.

Does anybody know why this is ? Does it have something to do with the articles I read and found in rvator on cracks forming at the end of the stiffeners near the trailing edge.

Concerning those cracks risks. Does anybody know what the ideal distances are to leave between the front spar and the trailing edge inforcement wedge to have minimum risks of cracks later ?

Thanks in advance

 

[woodmanrog]

My experience with cracking

I am now in the process of making a new rudder for my 6. It is the RV8 folded rudder. The rudder should be folded tight enough so that there is no pulling outward when the final rivets are installed in the forward edge. RTV should be run the entire length of the folded edge to minimize vibration and eliminate the possiblility of cracking. I also heard that putting pro-seal between the stiffeners and the rudder and then riveting them together will help eliviate cracking from vibration. (this is the problem I have). Hope this helps.
FYI Van started using the same rudder kit on the 7 as he does for the 9. Larger rudder for more rudder authority in spins I presume. I would use it on my 6 but I don't want to second guess Van.
Woodman

 

[jmjula]

Van's upgraded the RV7 rudder from the smaller RV8 folded style to the larger RV9 2-piece. The reason for this was less than desired spin recovery with the smaller rudder. If you do a search, or look through Van's sight, you will find all the details.

 

[JurgenRoeland]

I also read about the larger rudder for spin recovery. I'm just curious about why the new RV7 (like mine) now comes in two seperate skins and no longer as a prebend skin.

 

[jmjula]

The larger rudder is simply built that way. I actually built both because I started way too long ago. Here is my page showing the newer rudder: http://jmjula.home.comcast.net/~jmjula/rudder.htm

 

[LifeofReiley]

It's...

a parts count issue... same as -9 rudder parts, Profit.

 

[L.Adamson]

I figure that the shorter "classic tail" rudder on my 6A, has less drag, and therefor makes the plane faster....

I wonder if there is any truth to that?

L.Adamson --- RV6A

 

[JurgenRoeland]

Thanks guys, that clears things up.