Attaching elevators to HS advice!

[Ivan Kristensen]

I have attached the elevators to the HS and the next step is to align and match drill the elevator horns as per instructions on page 11-3. Step #6 on that page indicates to put the elevators in "trail" position and that I will most likely find a mismatch at the bottom end of the two elevator horns.

"In trail" I take to mean that the two elevator halves are perfectly aligned to each other and that the counter balances are matched to the HS.
In making sure that the in "trail" alignment was accurate I used a laser level and to the naked eye and the laser level they are perfectly aligned.

My problem is as follows: With the above set-up in place the right counter balance is perfectly aligned with the stabilizer but the left counter balance is misaligned by 3/16" at the forward most point.

I called Van's with this problem and was told to ignore the counter balance misalignment but to maintain an elevator halves alignment.

I tend to agree with that assessment except that it bugs to see these counter balances not being aligned with the HS in the neutral or trail position.

My question to all you RV-10 builders is; have any of you experienced the same problem (Van's tells me that some of you have) and if so what if anything did you do about it?

I really would like to hear from as many of you as possible on this matter and to find out if there is a solution. Thanks in advance.

 

[cnpeters]

I have the same issue with my -9A. And I have heard about it with others here in the forums. Not much to do - it is imperative that the trailing edges are aligned, whereas a little misalignment of the counterweights won't matter.

 

[RV10inOz]

And when drilling the holes in the norns, suggest you make a jig by finding a bolt the right size that suits the bearing and then drill a hole in the centre of the bolt.

Now you can use the "Holy" bolt as your guide to centreing the whole thing.

Did that make any sense

DB

 

[TSwezey]

Mine is slightly off also.

 

[sportpilot]

in trail

I did not address any trailing edge issue. I aligned the counter balance arms with the HS with duct tape as instructed in the plans. I drilled the aft most horn as the demisions indicate. with the counter balance arms taped flush to the HS With the block of wood in place I match drilled the the right side horn. I have previously built an RV 9 in the exact same way and it flies in perfect trim. I dont see the problem.

 

[Rick S.]

Ivan,

Mine came out perfectly aligned...maybe just dumb luck but with the counterbalance arm aligned with the HS, the trailing edge was perfectly aligned between the two elevator halves. What didn't line up perfectly was the elevator horns, they were off about an 1/8" from each other. This is not a factor since the horns are drilled together with the elevators in trail..as per the plans. I don't know why mine came out perfect and others didn't...but can say that I was very careful building those parts because they needed to "match".

I am surprised Van's said they heard of it occuring, and don't offer a reason. You can manipulate the counterbalance arm up or down during construction prior to drilling and riveting the skins. I did make sure that the arm was symmetrical to the elevator while match drilling, clecoing the skins and during riveting, this maybe why I came out OK.

FWIW, I can't believe I'm giving you any information about anything to do with airplanes. I met you many years back as a wide eyed teenager at one of the first TOC's in Vegas, it was either 1976 or 1978?? maybe later. That darned Austrian Hanno Prettner (sp)? Had an airplane on rails!! I still have the pink jacket! They called you the Gentle Giant from Canada, and you were indeed that!! What a shot in the arm for R/C in the late 70's and 80's thanks to the late Bill Bennett, the Circus Circus Hotel and Model Airplane News...It's an honor to be able to even think I can help you get over a hump in your RV-10 build. Geezzz I'm still wide eyed Umm...yes I did get my start in model airplanes, my old expired AMA number was 98033..

 

[Rupester]

ALignment

Although the Vans 'structions don't tell you, in most cases you must choose between having the trailing edges aligned perfectly OR the counterweights matched to the HS. Seldom do they both align at the same time. Vans says to to clamp the counterweights to the HS and drill the horns, but a number of builders have thus ended up with elevator trailing edges that don't align well. I recommend clamping an 8' or greater straightedge (alum. angle) to the trailing edge, then clamping one c'weight to the HS, and THEN drilling the horns. That way you may end up with one counterweight slightly "off" , as you apparently noticed... but you'll have a perfect trailing edge.

 

[Rick S.]

I reiterate....work to get your alignment of the arms while building the elevators...after the skin is on and riveted, it's too late, if your arms do not align with the HS but the trailing edges align then you did not get the counter balance arm of the elevators inline with the centerline of the elevator.

Having built many similar assemblies prior, I knew that these parts needed to be aligned with each other. Van's really should point out that they all should be aligned during assembly, not just the fact that the arms might be out of alignment, just align the trailing edge, so sad, to bad, so sorry. Looks like ****, minor affect on flight...but it just ain't right. I circumvented the plans and hung the elevators to the HS and then finished up the balance arms while keeping the T.E. aligned, I matched drilled the arms while maintaining thier alignment with the HS...it's one area that you really need to step beyond the plans and see the whole picture. A plans revision would be great to show this...I write too many revisons for other stuff in my day job, I'm not doing it...but this is the best way to get them not only good enough for flight but good enough for the eye.. as I said in the prior post, You can manipulate the arm up and down to perfectly align with the HS, prior to match drilling, takes a little foresight into the total picture, not just the single part you're working on. Really...honest...I wouldn't kid ya