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Rudder Leading Edge

I'm trying to finish up the rudder and working on rolling the leading edges of both rudder skins to meet. I'm having a heck of a time making the curve without risking bending the skin at the spar. Is anyone else having any problems and if so, how are you tackling this? I've read the section in the manual on how to do it but I can't seem to get it the final 25% so the holes match up as best as possible and to minimize the preloading due the the natural spring back nature of the skins.

One thing that I"m thinking is contributing to my problem is that I've primed the inside of the skins. It's a very light coat just enough to cover the aluminum. Is it possible that the primer is not allowing me to make an easy bend?

Can I just pull the two halves together? Or is that going to be too much preloading? I got the shorter tabs together at the top, but there is also some preloading on these. The shorter tabs were easier to work with.

Any and all comments would be appreciated.

Bill S.
West Chester, OH
#140100
 
Section 5.9 on page 05-13 talks about using a water pipe or a broom stick to roll the leading edge. I have had good success using a large wooden dowel (1-1/4" to 1-1/2") with a minimal (saw blade width) groove of 1/2" depth cut along the length of the dowel. The dowel should be about a foot longer then the skin so you have two 6" handles on either side when the skin is inserted in the groove.

Insert the skin into the groove and securely tape the skin to the dowel. As you turn the dowel, keep the section of the skin that meets the spar as flat as possible. This will keep you from creasing the skin along the flange. Turn the dowel until it is touching the back side of the spar. It may take a few tries until you have a curve that you like.

The primer on the skin will not effect the ability of the skin to maintain a curve.
 
I think it is one of those processes where it seems like you are getting nowhere and then eventually things start lining up. Be patient and keep massaging it. It will happen....I did a lot of searching and didn't find any real cheats to make it very easy...
 
I know in our build class when we did this it was stressed to pull back as much if not more then you roll (back in this case being pull toward where the nose of the aircraft will be. It seemed to work really well.
 
I appreciate the comments. Suffice it to say that I am totally frustrated with this and cannot figure out what I'm doing wrong. It seems so simple and the plans make it sound so easy. Tape and roll.

I have worked on it for a couple hours each of the last 4 days and I'm not happy with the results. I have tried dowels from 7/8 in diameter to 1 1/4. Still unable match up the holes without using both hands to pull it together, which doesn't seem right at all.

Can someone reply with how much spring back tension would be acceptable? Do the holes have to pretty much line up, or is a 1/2 inch or 3/4 inch separation acceptable and just pull the skins together the rest of the way and cleco?

Is it possible to unroll/unbend what I've done so far and start over?

HeliCooper mentioned pulling back a lot as it's rolled. So I guess that means clamping the whole rudder to my workbench to apply that much pull back force.

Ron B......have you completed this step yet on your rudder assembly? If so, how did it go?

Thanks

Bill S.
#140100
 
I'm pleased with mine, but the radius is not perfect. There is a slight crease where the bend starts. I would say I had the holes quite close to lining up but the skin angles to one another were a bit off. I had to reach inside with a dowel and push a little, while riveting to get the two skins to nest each other properly. The clecos pulled them in but when one was removed for riveting the skins would separate.
 
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