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Asymmetrical Elevator Problem

PostPosted: Tue Dec 19, 2017 10:27 pm
by Bacon8tor
After finishing the tail assembly on my Onex I discovered that the trailing edge of the right side elevator was 3/4" higher than the left elevator. (I could say the left side was "lower" but I will say right side higher for simplicity).

I'd like to blame it on Sonex for sending me a bent elevator horn but it is more likely me fitting the horn all nice and neat into poorly cut elevator skins. Both elevators still have smooth travel and the drive assembly (horn) appears square with the rest of the horizontal stabilizer.

if I leave it like it is I wonder how much of a trim/drag issue this will be. If I fix then how? Will I need to build an entirely new elevator assembly? What about taking a torch to the horn allowing the right elevator to "twist" down to even with the left? Would this compromise the strength of the horn beyond safe?

Re: Asymmetrical Elevator Problem

PostPosted: Tue Dec 19, 2017 11:11 pm
by daleandee
Bacon8tor wrote:After finishing the tail assembly on my Onex I discovered that the trailing edge of the right side elevator was 3/4" higher than the left elevator.


Hi John,

Did you contact tech support for their advice? Not sure if they are still open with the holiday coming up.

Anyway ... I had made an error on my elevator by missing the alignment of the hinges. Not the problem you have but the answer for me was to order new parts and rebuild the entire assembly. I wasn't going to short cut any areas and certainly not such a vital area as the elevator. Seems the replacement parts at the time were about three hundred bucks. Lesson learned ... I needed to be more careful in the future.

Having said that ... you need to determine where the twist is. Perhaps your fix could be done by drilling out the drive assembly from the root ribs. After replacing the root ribs, the drive assembly can be correctly aligned when fitted to the new root ribs and riveted in place.

As for me ... no I would not fly an elevator that far out of alignment. Don't let it discourage you. It will fly soon enough.

Dale Williams
N319WF @ 6J2
Myunn - "daughter of Cleanex"
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
Signature Finish 2200 Paint Job
166.2 hours / Status - Flying
Member # 109 - Florida Sonex Association
Image

Re: Asymmetrical Elevator Problem

PostPosted: Wed Dec 20, 2017 8:35 am
by Stogie6
[quote="Bacon8tor"]After finishing the tail assembly on my Onex I discovered that the trailing edge of the right side elevator was 3/4" higher than the left elevator. (I could say the left side was "lower" but I will say right side higher for simplicity).

I had a similar issue with my Onex tail. Let me revisit my build photos and remember what we did to correct the misalignment. I can also send photos of what I am flying with. So far, my only issue is a slightly heavy left wing.

Re: Asymmetrical Elevator Problem

PostPosted: Wed Dec 20, 2017 12:12 pm
by n502pd
daleandee wrote:
Bacon8tor wrote:After finishing the tail assembly on my Onex I discovered that the trailing edge of the right side elevator was 3/4" higher than the left elevator.


Hi John,

Did you contact tech support for their advice? Not sure if they are still open with the holiday coming up.

Anyway ... I had made an error on my elevator by missing the alignment of the hinges. Not the problem you have but the answer for me was to order new parts and rebuild the entire assembly. I wasn't going to short cut any areas and certainly not such a vital area as the elevator. Seems the replacement parts at the time were about three hundred bucks. Lesson learned ... I needed to be more careful in the future.

Having said that ... you need to determine where the twist is. Perhaps your fix could be done by drilling out the drive assembly from the root ribs. After replacing the root ribs, the drive assembly can be correctly aligned when fitted to the new root ribs and riveted in place.

As for me ... no I would not fly an elevator that far out of alignment. Don't let it discourage you. It will fly soon enough.

Dale Williams
N319WF @ 6J2
Myunn - "daughter of Cleanex"
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
Signature Finish 2200 Paint Job
166.2 hours / Status - Flying
Member # 109 - Florida Sonex Association
Image


As a scratch builder, I can fully understand what has happened. And I fully agree..fix it if it isnt right. The simpelist fix, IMHO, would be to drill out one of the root ribs, either get a new one from Sonex, or make a form and bend up your own! However, I am not sure a kit plans set would have the complete measurments for making your own. Then , of course, lay both elevators and horn assembly on a flat surface, keeping elevators alligned, and just reinstall rivets on the one new root rib. Just dont ask me how I know this!!!