Hello everyone,
Lets start this off with a little history....
While waiting on the quick build fuse and wings for my brother's -10, I ordered a RV-7 empennage... I assembled everything except the elevators. Shortly after that I found a good deal on a RV-7 quick build fuse, wings, and finished empennage, so I bought it knowing that I wouldn't get around to building until the -10 was complete. That was a few years ago.....
The -10 is complete and flying, and performs EXACTLY as Vans says per their specs. Top speed and climb etc. I am very impressed!
Now on to the -7..... been working on it for a few months. I wanted to finish up the tail rigging a few weeks ago and that is where the problems begin. I leveled the fuse and mounted the horizontal stab (built by the previous builder). Next I attached the elevators (also built by previous builder) and noticed that when the counter balance arms were clamped to the horizontal stab that the elevators were not in trail. I checked everything that I could and adjusted the pivot points in and out until I decided that something was wrong with the elevators... I spent the next 5 days building the elevators from my original kit making sure everything was perfect. (except for ONE thing...the tips!) I used a bending brake for the trailing edges and used huge blocks of machined aluminium to make sure nothing was twisted.
I mounted the newly constructed elevators friday and saw almost the same twist / mismatch with the "other" elevators although it was a smaller distance between the mismatch now the difference is 1/4" at the counter balance tips when the trailing edges are parallel. I removed the elevators to check them for flatness and they are perfectly flat but the counter balance arms aren't the same. Before I riveted the elevators together I tried to move the tip rib assembly around and if you move it either up or down it distorts the trailing edge so, there is only one way it goes together.
I spent some more time thinking it over and for the life of me I can't figure out why the CB's are not the same. So, I made the trailing edges parallel and drilled the horns. I kinda wished I would have asked this question earlier but oh well.....
How do you make perfect elevators?
Lets start this off with a little history....
While waiting on the quick build fuse and wings for my brother's -10, I ordered a RV-7 empennage... I assembled everything except the elevators. Shortly after that I found a good deal on a RV-7 quick build fuse, wings, and finished empennage, so I bought it knowing that I wouldn't get around to building until the -10 was complete. That was a few years ago.....
The -10 is complete and flying, and performs EXACTLY as Vans says per their specs. Top speed and climb etc. I am very impressed!
Now on to the -7..... been working on it for a few months. I wanted to finish up the tail rigging a few weeks ago and that is where the problems begin. I leveled the fuse and mounted the horizontal stab (built by the previous builder). Next I attached the elevators (also built by previous builder) and noticed that when the counter balance arms were clamped to the horizontal stab that the elevators were not in trail. I checked everything that I could and adjusted the pivot points in and out until I decided that something was wrong with the elevators... I spent the next 5 days building the elevators from my original kit making sure everything was perfect. (except for ONE thing...the tips!) I used a bending brake for the trailing edges and used huge blocks of machined aluminium to make sure nothing was twisted.
I mounted the newly constructed elevators friday and saw almost the same twist / mismatch with the "other" elevators although it was a smaller distance between the mismatch now the difference is 1/4" at the counter balance tips when the trailing edges are parallel. I removed the elevators to check them for flatness and they are perfectly flat but the counter balance arms aren't the same. Before I riveted the elevators together I tried to move the tip rib assembly around and if you move it either up or down it distorts the trailing edge so, there is only one way it goes together.
I spent some more time thinking it over and for the life of me I can't figure out why the CB's are not the same. So, I made the trailing edges parallel and drilled the horns. I kinda wished I would have asked this question earlier but oh well.....
How do you make perfect elevators?