What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Elevator Mismatch (Drilling Mistake)

Rteem

Member
So, looking for some sanity or help from the community.

Part of mounting the elevators requires having them both at neutral, and using a guide block / clamp to make sure that they are drilled both perpendicular and even to each other.

Unfortunately, the clamp I chose to use didn't quite hold against the will of a new #16 drill bit to wander.

I now have a hole that is off by a slight amount on the left elevator, and the result is that the elevators are about 1/4 inch off at the foremost section where the weights are.

I'm looking for recommendations on how to recover, here's some things I've considered:

1. Rebuild one of the elevators - I simply don't see how without massive work I could replace just the horn because the skins won't peel back nicely anymore now that they are rolled.
2. Fill the hole with weld, and redrill the elevator horn
3. Set neutral to split the difference (so one rides 1/8 low and the other 1/8 high)

Any help or suggestions would be GREATLY appreciated... pictures here:
https://photos.app.goo.gl/ZHBQydUfhDd6ot5K6
 
I saw photos just a few weeks ago where someone corrected a similar mistake by flowing metal into the hole with an appropriate welding tool, dressing smooth, and re-drilling. That's the route I would take first. Accepting a split deflection on the elevators would be a nonstarter in my opinion.
 
Did the same thing, had a welder fill it, sand, paint and re-drill ... perfect now ... consider that a practice run.

Seems like everybody knows a welder, it took all of 10 minutes.
 
Weld the hole

I dorked one of mine. Take it to a good TIG welder. Mine was welded and so smooth if not for the paint, I wouldn't gave spotted the weld. I redrilled and applied some matching paint.
 
Been there

I welded in a small piece of metal the thickness of a washer and re-drilled. Your not the first. Weld and move on, it will be okay.

n3vgy8.jpg
 
When I purchased my RV7A from the builder he had mis-drilled the elevator horn so poorly that there was almost a 1 inch difference between the left and right side elevators. To compensate for this difference it appeared he mis-rigged the ailerons. Bottom line: the aircraft wanted to roll upside down the faster it flew.

The fix for this was to weld closed the old holes and drill new ones correctly. Had to re-rig the ailerons and balance the elevator. But after the corrections were made the aircraft flew wonderfully. No issues since and it’s been four years.
 
I welded in a small piece of metal the thickness of a washer and re-drilled. Your not the first. Weld and move on, it will be okay.

n3vgy8.jpg

Welding a piece as a doubler is a great idea but consider welding the piece on the outer side since you might run into issues with the spacing to the center bearing.
 
Nothing structurally wrong with a patch, but . . .

A good TIG welder can weld inside the hole, a little grinding and it will be flat => recommended.
 
Yep, have it welded and redo. I had to do it on my canopy frame where the nylon slider is.
 
I goofed up mine also. I googled welders in my area and found a custom car shop that had good reviews for TIG welding. I showed up with elevator in hand and the first thing the guy said was "Is that off one of those RV planes? Some mismatch drill issue? I've welded a few of these over the last couple of years". -Made me feel a little better. :D
 
You are in good company

Welded the misdrilled hole and redrilled

Speaking from experience
 
An alternative fix if you have a lathe but no welder........ Dremel one hole over and concentric. Redrill larger, then turn up a steel shouldered washer to press fit in the hole.
Stewart Willoughby, 6, paint is next
 
It takes no time for a welder to fill and grind it ... 10 minute fix and they would probably charge you $25.

It's probably easy to conclude you can just clamp these two parts together and drill the hole but the tube that is welded to the arm isn't perfectly aligned from part to part which is why you get that offset alignment and why Vans has us drill the hole in this way .. I bet a lot of builders are doing this thinking it would be easier than per the manual.

Pretty much every 14 builder I talk with outside the forum has had to re-do this for one reason or another.
 
Last edited:
An alternative fix if you have a lathe but no welder........ Dremel one hole over and concentric. Redrill larger, then turn up a steel shouldered washer to press fit in the hole.
Stewart Willoughby, 6, paint is next

This is similar to the approach I went for when the project I took over had this issue. I over-drilled the hole and machined and pressed in a shoulder washer with the hole drilled in the correct place.
 
Welding

When welding a doubler like this try to avoid square corners. If a round washer is needed make one edge of the washer a teardrop shape. Both these methods will reduce the stresses inherent in the welding process. If you are hiring the welding done and a TIG is being used, stress to the welder the importance of slowly cooling down the weld by holding the torch in place after the arc is terminated until the argon flow times out. No need to use a high strength filler rod. ER70S2 is fine.
for strength four relatively small tack welds would be sufficient. However it is standard practice to weld the doubler all around.
 
Back
Top