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So I might be super dense I did end up having to re-bend my root rib drive plates since I bent then in the wrong direction. But I cannot figure out this skin.



I marked out the lines at the measurements and I marked out the do I then cut a straigt line from the notch to the marking on the top half of the skin??? would that not change the angle of the cut of the bottom half of the skin and why would you just not print that if you wanted a different angle from the top half vs the bottom half.

I think this is what they are trying to get at but just seems weird to me. note that this is looking from the top edge across the bottom. Which is not illustrated in the plans.



Also how structural is the drive plate should i be concerned that I bent it back from a stress point of view?

Does not look like the pics are playing nice they can be found in the last two pictures on my most recent post of my eaa builders log located here https://eaabuilderslog.org/?blproject&proj=7Wc0KY8D6

Hi Juan

I couldn’t figure out exactly what your main question is, hopefully someone else has that answer. As far as the “rebend”, this is a super critical piece for safety of flight. Please check with sonex technical support and tell them exactly the process you went through on these parts before you continue with them. Then.......build on.

All the best, Gordon

I think you are asking about the 7/16” difference shown in the plans. The leading edge of the ruddervator is not vertical, but angled aft to allow for movement in both the up and down direction. I believe the 7/16” difference is not to angle the rib, but to allow the rib to stay perpendicular to the skins. You can test fit the rib in the skin to prove to yourself that the line you connected follows the rib before you cut the skin. Don’t know if that helps or not, good luck.

You may want to drill out the rivets in the horn anyways to replace it if you did bend the wrong way first, bent back to center and then bent the right way. I’d buy new aluminum sheet, trace and remake those horns, you’ll be surprised how easy it is to duplicate with a band saw and clecos to duplicat the holes.

I will be replacing the drive plate, as far as the ruddervator skins I was talking about the 7/16th difference. brining in that lower corner could result in two things.

1. it changes the bottom of the skin to have a diffrent cut angle from the top due to bringing the corener in relative to the uper corner but having the same end point on the bottom, (i think this is what is intended and it is what i have marked on the pictures in the build log.,

OR
2. its a notch on just that edge but the upper and lower retain the same angle and there is just a notch across that front face of the skin. (The confusing part is i would expect the diffrent cut line to be indicated in the plans for the top view as a dashed line showing the reduced angle underneath or a bottom view for reference of the diffrent angle.

Also is it just me or is the side view to top view rotation just unclear in general in the plans i think i have figured out that the side view is rotated counter clockwise to the top view but it just seems weird to me since that ends up fliping the part relative to the front view. Part of this confusion is probably not having a full set of plans and just having the tail kit plans that dont allow me to see the big picture but in general i get that feeling from most of the three view depictions the front and side views do not match up relative to the top view, although taken as a pair (top/front) or (top/side the make sense the (side/front) appear to me to have some odd rotation. i wish i could explain it better but thats the feeling i get every time i see a three plan depiction.

That skin cut can definitely be confusing, and I botched my first one and had to order another ruddervator skin.

Basically, you just need to identify and mark the 3 points that the plans are showing you. 1 point each on the trailing edge, the top leading edge, and the bottom leading edge, then draw the cut lines to connect the dots.

When looking at the plans page picture that's in your blog, the bottom left figure is helping you orient the part. The bottom right figure is telling you the point on the trailing edge and the point on the top leading edge. The top right figure is telling you the point on bottom leading edge. Measure twice cut once to connect the dots.

One thing to note (and can add to the confusion) on that bottom right figure... it's assuming you're looking at the part as if it were facing you while laying flat behind a plane of glass. When you set the piece on your workbench, the face nearest you (the top of the ruddervator) will be at an angle relative to your table. So your table isn't the "plane" that it's referencing, rather it's referencing the plane of the top skin. Understanding this can/will help you on this part and many more parts to come.

lakespookie wrote:Also is it just me or is the side view to top view rotation just unclear in general in the plans i think i have figured out that the side view is rotated counter clockwise to the top view but it just seems weird to me since that ends up fliping the part relative to the front view.

Here's one way to imagine the views in the plans. The bottom-right figure in your plans picture for instance. Imagine grabbing the part as depicted in that figure with 1 hand on either end of the ruddervator (inboard/outboard ends.) When the view shifts left, your left hand would come towards you and your right hand away from you. To go to the top-right figure (from the bottom-right figure), you'd bend your elbows up and curl your wrists up. This is the way all of the plans parts are depicted, and the location of the figures relative to each other on the page tells you which way to rotate them.

For interpreting drawings, pretend the main drawing is at the bottom bolt a bowl. To get to the side, top, or bottom view slide the part up the bowl. The bowl "rotates" the view for you.

Bryan Cotton wrote:For interpreting drawings, pretend the main drawing is at the bottom of a bowl. To get to the side, top, or bottom view slide the part up the bowl. The bowl "rotates" the view for you.

Much better analogy than mine.

I love the bowl analogy and yeah it all makes so much more sense now.

They taught us the bowl method at the Sonex workshop.