Elevator counterbalance and horizontal

[clutch22]

(Pics shown below)

So I'll start by saying that this tail kit came from a previous builder that left me with the elevator final assembly point to pick up at.

The previous builder had slightly elongated several holes in the counterbalance rib that I was able to clean up round for .128" oops rivets. This should have probably threw a red flag and told me that the parts were not fully correctly formed/fluted when he final drilled them. But instead (hardly knowing any better) I pressed on and when I finished this right elevator, I did notice a little warp in the counterbalance arm and figured I would wait and see how it looked in the tailcone attach phase. Now I have it attached to the horizontal stab, and the upper surface just nicks the horizontal. The lower surface looks fine.

So the way I see it:
I'll either blend out the forward part of the counterbalance skin and rib, and still have more than 2D e/d to the rivets.
Or I can later on in the build, when I have some down time, build a new counterbalance assembly, and have to use a few more blind rivets this time.

By the way, I'm at the point where I am ready to drill my center bearing hole through the elevator control horn. I don't see any reason to let this counterbalance issue keep me from proceeding to drill it out, right?

Current condition:
https://lh6.googleusercontent.com/-...I/AAAAAAAAAWY/xGsMiCDq85w/w485-h861-no/13+-+3

Sharpie somewhat showing if I was to feather the counterbalance skin:
https://lh3.googleusercontent.com/-...I/AAAAAAAAAWI/sy8IaKi_nZ8/w485-h861-no/13+-+1

 

[alpinelakespilot2000]

Hi Andrew-

I had a similar problem and this is how Van's had me fix it. My RV-9 tail should be VERY similar to your RV-10.

1st of all, if you have not yet drilled the elevator horns, you may be able to adjust using the rod ends to get the counterbalance parallel to the HS.

Alternatively, if as I gather from your post, the counterbalance actually is not square to the trailing edge of the elevator (meaning the problem really is in the elevator), this will probably be a relatively easy fix. If you take out some of the rivets right at the joint where the elevator spar and counterbalance arm meet, both in the skin-skin, skin-spar, and skin-counterbalance rib, you will be able to pivot the counterbalance arm a bit until it is square Then, once square, drill a few of those holes up to 1/8, redimple, and then re-rivet. Everything should be square now.

Shaving off some of the counterbalance skin and rib, besides looking a bit odd, may make it difficult to get your lead weight in without it rubbing on the HS or at least make it sit proud of the elevator counterbalance rib and skin.

Hope this helps.

 

[Jesse]

I have seen these twists before that straightened out when riveted onto the elevator, but it had to be checked tight and drilled straight. Yours was obviously not done this way by the previous builder. I don't see any reason why you couldn't drill the horn, but you may want to do so with the trailing edges even rather than the counter balance arms even with the HS. I would certainly recommend replacing the counterbalance arm or possibly buying a built elevator and putting yours on a shelf for a day when you accidentally back your tail into the wall of a t hangar. If it's the left that you need, I know where one can be had in FL.

 

[clutch22]

Thanks for the ideas. I guess when I get around to fixing this, I'll remove a few areas at a time until i can free it up a little and see what the situation looks like.

If it's the left that you need, I know where one can be had in FL.

It's the right elevator that has the problem. My left elevator counterbalance gap was perfect. Thanks anyhow!