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Elevator balancing question

GK14

I'm New Here
Need some help regarding my right elevator. Since I’m waiting for my wing kit to arrive, I decided to paint sections as I go. I balanced the elevator by drilling out some lead from the fairing-side counter weight to achieve a slightly nose down balance - knowing the paint would add some weight. Well, I took out way too much lead and now I’m nose high. The paint was heavier than I thought…

I can get balanced with adding approximately 90-100 grams of lead at the location of the lead weight.

I did not use a nut plate (on the fairing side) to install the counterweights - it’s bolted on and safety wired - not an option to take off the current counterweight.


Solutions I’ve thought of but don’t love:

1: Drill a hole in the fairing and add an epoxy (and maybe some ground up lead) slurry, put it nose down and hope it adheres to the fairing appropriately. Would be near impossible to fix if it didn’t adhere. Also, fixing the hole would be a pain now that it’s almost done being painted.

2: Pop rivet a bracket next to the current counterweight, fill with epoxy flux and then add lead until it’s balanced. I included an example picture of a bracket taped to the location it would probably go. My concern is that if the pop rivets ever failed or the epoxy came loose, the control surface could jam.

3: Do nothing. Take comfort that I got one elevator balanced and build on.

Is there an easier way to balance an elevator? How should I proceed? Thanks!
 

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balancing ideas

There are self-adhesive lead weights for balancing alloy wheels, perhaps that is a solution, with added pulled rivets for extra security?
If the paint was applied too thick then it could be wet sanded and buffed (if 2K single stage) to reduce the weight.
 
What I had done here, prior to closing the cap, installed two additional nut plates for this purpose.
Instead of pop rivet, I suggest using rivnut, perhaps in the same pattern at the original weight. Then you can use drilled bolt to attach the weight and then safety wire it.
 
Go to any good golf club store and buy some lead weights that are used when making clubs to set swing weight.

https://www.golfworks.com/swingweighting-supplies/c/21/

The small lead cylindrical weights, or the tungsten powder can be used to weight up the tip of your light elevator counterbalance. They also have sticky lead flat pieces like tape, that go on the sole of the golf club to alter swing weight that could be easily stuck on in your chosen location, and maybe some extra epoxy to be sure it stays there. You can drill a hole near the tip of the counterbalance, add the weight, and then re-epoxy it closed and finish sand. Keeping the added weight as far forward as possible will lessen the amount of weight you need to add. You shouldn’t need much.
 
So you didn't install the platenut ... How about installing a rivnut at that location? This would achieve the same result as if the platenut were there.

Also, you could blind rivet weights at the platenut location....
 
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Lead shot

You could add lead shot in the holes you drilled out and use epoxy to hold it in, that is if enough lead shot can be added to make up the weight you require
 
RE: Elevator Balancing Question

I am very curious why there are no RV-14 recommendations for 1. The weight of the elevator counterweights, and 2. How the elevator should be balanced with no load (on the ground). Is this similar to other Van’s models?
 
I am very curious why there are no RV-14 recommendations for 1. The weight of the elevator counterweights, and 2. How the elevator should be balanced with no load (on the ground). Is this similar to other Van’s models?

The amount if weight required will vary with paint weight so there is not set amount you can recommend. You add enough weight to balance.

One could mix lead shot with epoxy to fill the holes. One can also pour lead into plaster of paris molds to make any shape you want. It is very easy to work with.
 
Thanks all. Gonna try to place a couple of rivnuts and then add weight (maybe a tungsten or lead powder mixed with epoxy) secured by AN bolts that I can safety wire. Would definitely add a platenut next time…
 
Thanks all. Gonna try to place a couple of rivnuts and then add weight (maybe a tungsten or lead powder mixed with epoxy) secured by AN bolts that I can safety wire. Would definitely add a platenut next time…

I would not do rivnuts, they will inevitably loosen over time and will create a real headache down the road.
I added a lead shot to fiberglass resin and flox mixture and added it to the tip of the fairing thru a hole I drilled in the front of the fairing.
Keep in mind a loose weight can cause you to have a really bad day with a jammed elevator.
 
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I was in the same place that you were when I reassembled my elevators after my plane was painted. I had drilled holes on the wrong side of one of my lead weights and could not get to them to add lead for balancing them due to the fairings covering them. What I did first was to determine how many grams of lead I would need to balance the elevator by placing lead at the rear of the elevator lead weight. I next took a strip of flat lead and cut it to the width of the rear of the lead weight block (narrow portion). Once I had the correct weight, width and length I needed, I drilled two holes through the rear of the lead strip and lead elevator weight. I finished it by adding a thin layer of JB Weld on the back of the elevator Lead weight and my new strip of lead, then screwed the 2 pieces together. That was nearly 1000 hours and 12 years ago. Good luck with your balancing. Lots of fine options have been shared.

Steve Koziol
RV9A
N424JK
987 Great Flying Hours!
 
Related RV-10 elevator balance question

I have a minor cosmetic problem on the bottom of one elevator trailing edge skin. I contacted Vans and they said using some filler as a fix would be fine as long as it doesn't put my elevator out of the balance specs listed in the attached table.

If I'm reading the table correctly, I can be trailing edge heavy by 37.5 in-lbs.

How does one go about accurately measuring the "trailing edge heavy" balance in in-lbs? Do I literally need to figure out how to attach a bending beam torque wrench to my elevator horns and measure the in-lbs of torque needed to lift it? That's what it sounds like but, as a first time builder, I'm not familiar with how to balance control surfaces.

Would that listed limit be for one, or both elevators together as a unit? The table lists elevator (singular). I'm also assuming the measurement should be done without any controls attached to eliminate friction from the equation?

I couldn't find a good resource on how to measure and balance a control surface. What I could find seems to indicate that it's design specific. Should an RV-10 elevator always be trailing edge heavy, vs neutral, or nose heavy?

Thanks as always for any insight.
 

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Here's how I would approach it.

The distance from your hinge line to the trailing edge of the elevator is your "inches".

The weight of the elevator as measured at the trailing edge will be your "lbs".

Multiply them together and if the number is less than 37.5 you are ok.

How to measure these is an exercise left up to the reader.

I didn't do this, because mine were in very close balance, but just thinking about it, the number seems quite high. If your rudder distance is about 12 in then you can have 3 lbs of weight at the trailing edge? Seems high to me, but I'm on my first cup of coffee.
 
Forget nutserts for this job. Wait until after paint and permanently attach the necessary mass.

This is a stack of primed and painted steel plates attached with five 5/32 SS pulled rivets.
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You might want to verify with Vans. I think the 14 is the same as the 10 and you just install the weight vans give you. The are not balanced like the rest of the rv fleet.
 
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