In putting the finishing touches on the elevators, I attached them to the HS and started to take some measurements to check for trueness. What I found was a bit disturbing. With the elevators in the same plane and the trailing edges matching up, the counterbalance arms are not in agreement. That is to say that one of the arms matches with the HS, the other sits about 1/2" higher than the HS.
The real problem is that no warpage can be identified. Ive been stumped on this for a week, and so has another friend who is an experienced builder. We have measured 6 ways to sunday and every part looks pretty true. Putting the elevators side by side on a flat surface and the counterbalances are mirror images of each other. I called Van's and they said that 1/4" would be quite acceptable and even somewhat expected, but that at 1/2" something is not right. The problem is that to Mr. Perfectionist here, 1/4" isn't good enough either and nobody can seem to find where the problem is.
- John
http://www.rivetbangers.com - Now integrating web and mail!
Current Build: 2 years into a beautiful little girl
Vans support was literally "You have a warp". Not much more. Though, it would have been difficult to give me more considering they couldnt touch it.
The current follow up to the story is that I took the elevators to another builders house last night who has a pool table. The one elevator checked out fine, but the second had a small warp on it. Darned if it wasn't dang near impossible to find without an extremely flat surface. We took the trailing edge rivets out and it relaxed. So, now the counterbalances are ~ 3/16" out. I think that is because I didnt seam thier flanges well enough on the inside. I am going to play with that a little more. The real tough part will be to reassemble the trailing edge without doing this again.
As hard as I have worked at keeping things straight & true, I am no longer convinced that these pre-punched kits dont' need some kind of jig.
Ill keep you guys updated as I go.
John
http://www.rivetbangers.com - Now integrating web and mail!
Current Build: 2 years into a beautiful little girl
Simply re-riveting it will most like put it back to the same warped position.
But, if you re-drill it while it's straight and then rivet it back together it may help to straighten it out. Of course this means going the next size up in rivets to eliminate any elongated holes.
The other option would be to order new parts and build another one.
I did that on my left elevator even though I probably didn't "have to".
It was straight, but when I bent the tabs in where the trim tab is, the fold was too sharp and it cracked/split it. I could have just made a rib to go in there, but instead chose to order a new skin and stiffeners and do it again. The 2nd one came out great and it wasn't all that much extra money to do so, just extra time.
Agreed David. I can't just rivet it else Im back in the boat. The options are to either do as you suggest and go to an AN4, which is ok with me, or to add a few extra new holes to hold it in shape while I bring the old holes in line. Im going to fully explore both options before I go the reskin route. I dont want to have my own version of the 202 rivets to drill out procedure
http://www.rivetbangers.com - Now integrating web and mail!
Current Build: 2 years into a beautiful little girl
Spike,
Building a new elevator isn't very expensive and could be the best way to cure the problem. I had to rebuild my Left elevator 3 times before I got it right!
Dan
An update. When we last discussed this I had taken the rivets out of the trailing edge of the left elevator and it relaxed. I took it one step father and took out the end rib to skin rivets on side of the elevator and it relaxed a bit more. At this point I weighted it down and verified its trueness, working methodically. I then riveted the skin back to the end rivet.
At this point I jumped forward in Vans plans and fabricated the trim tab, and mounted it to the elevator, riveting the hing in place on the elevator making sure I kept the assembly true. The end result was excellent. The elevator was fixed in a true state, and that allowed me to align the trailing edge holes and adjust them as/if necessary to make sure that the trailing ege came out straight and true. The end result is no warp, no oil canning, etc.
Thanx for the thoughts guys!!
- John
http://www.rivetbangers.com - Now integrating web and mail!
Current Build: 2 years into a beautiful little girl
CJ
