How bad is it?

Thought I might make a run at completing the tail kit today,which began with drilling the elevator horns to the HS-411 bearing.
Measure twice (X 50) to cut once, and many hours trying to decide why this won't work, then finally just started drilling.
All was going well until I tried to slide a washer over the bolt. Started to get that hackle feeling up my spine as I noticed the closeness of the bolt to the horn tube. I shaved a side of the washer to get it over the bolt and up against the flange, all the while thinking, this can't be good.



Then came the nut, and indeed it definitely wasn't good. After many many minutes of staring in disbelief, I took the nut to the 3-M wheel and took down the sharp tips off the hex ends, which wasn't exciting me either, for clearance from the horn tube so I could turn the nut on the bolt, .


As you can see these holes I drilled are way too close to the horn tubes. I can just barely turn the nut even with the hex tips shaved down, and I'm not exactly excited about having the tail held together with an altered nut. Any one ever run into this trouble, and what was the best corrective action?

As I'm finishing up on the tail kit, I have learned so many things. Unfortunately they have mostly been after I have drilled or cut material that I realized I need back. I can't afford too many more of these type of lessons.
I think Van's could use a dense guy like me to build one of their kits at their factory and point out things that should be clearly written in their plans and call outs.
Getting tired of calling support looking for information and being told, finding or figuring out something is just part of the learning experience. C'mon! Just put it on the plans in the sequence of the build.
OK, done yelling. Any direction on my issue above is much appreciated.
Thanks
Tom

Did you drill the hole in both horns ? Do you have a photo of the how you secured the horn to the elevator ? I am puzzled why the tube is so close to the hole of the bearing ...

The nut and bolt don't rotate, so once they are in and tight things should be secure.

I would just modify the washers to get the radius needed and not touch/modify the structural nut and bolt.

If the nut is too fat to fit, you could try one of these -

http://www.aircraftspruce.com/catalog/hapages/MS21043.php

But get Vans permission first.

The other problem might be alignment. The elevator needs to move correctly and be centered vertically. If the alignment is off, more drastic measures are needed.

Did you have the elevator hinge bearing screwed in too far causing you to drill the hole in that location?

As said, use an MS21042 nut. Probably should have had the rod ends out another turn or two.

Thanks for the reply's everyone.
Yes, I know exactly how it happened. It's another one of the lessons learned on this project, the ones learned after the fact.
I've wanted to build an RV since I was in high school, 30 yrs. ago, and I always knew that I would never be satisfied with the first copy. Just about every step in the project ends with, if I could do that again, it would be perfect. But if I don't start now I probably never will. So.....
Back to the issue at hand.
I followed the drill instructions per the plans. I centered the elevators to the HS with the smart level.


Then matched the elevators using clamps and shims.

The right side yielded the same numbers as the left.

The horns didn't come out perfectly symmetrical, but certainly close enough.

Once secured in place, I used a piece of fuel tubing for a bearing protection bushing and drilled the first hole.

I repeated for the left side, then drilled the holes to final size, and that's where the trouble in the original post began.
A suggestion from a couple of you hit the nail on the head. When I completed the elevators, I screwed the rod end bearings in right to 13/16, just a 16th short of the 7/8" max and never looked back.
Now in the unforgiving reality of hindsight, if I would have unscrewed them just one turn, it would have turned out absolutely perfect.
My elevators exceed the max travel the way it's set up right now w/o touching the HS, so I would not want to have the elevator extended back any farther than necessary and created a bigger gap between them.
Like many of the other curse word creators so far, I'm sure after a night to sleep on it, it will work out fine (I hope).
Thanks again for all your help. You guys are top notch.
Tom

My center bearing bolt was also very close to the tubes of the horn, though not so tight as to preclude using the factory hardware.


I did have to "manufacture" a new tool to get that nut tightened though...


Had I followed the plans dimensions for setting the rod ends, I would have run into the exact same problem as you. I set the depth, hung each elevator, confirmed that I had good travel, and was almost ready to go to town with the drill bushing, when I noticed that the way things were, I was probably going to get a piece of the tube on the control horns with the bit.

Then I saw that the counterweight skins weren't parallel to the HS outer ends. Aha! On the downside, this meant some trial-and-error to get the alignment right, but when it was done, I was much more proud of the finished product. Only the control horn interference saved me from a potential bad gap...THE HORROR!!!

I can't provide any advice for remedying the problem, but it seems you've already got that. What I can tell you is that soon enough, you'll be past this and on to other things...and then one day you'll be flying.

to tight!

My 4 was close also, go with Gil's suggestion, you could also use the MS21042 Metal lock nut. Your not the first and won't be the last to do that. I love your statement that if you could do it again it would be perfect, I felt that way after my first build, I would do it all better and different. The truth is your the best your going to be when your done. Your work looks excellent by the way.

RT

This wont' be your last set of "special words" and sleepless night. It's part of the process....

Yes this is a very common issue and I agree Van needs a big red flag at this point in the plans. If you search the threads you will find a lot of information on how to address this issue.

Although frustrating you will get through this, drive on and by the time you finish this will be a lost memory.

Maybe a Socket Head Cap Screw would work better. (Allen wrench)

I had a problem, too, on my -7. The clearance between the horn shaft and the bolt head was tight, but acceptable. I found that the alignment in the vertical direction (along the direction of the arms) was noticeably out of alignment. After review with the VAF brain trust and Vans, it was "build on" but it was frustrating!

This section of the plans could use some more detail, indeed!

http://www.vansairforce.com/community/showthread.php?t=97098

Zero4Zulu said:

Maybe a Socket Head Cap Screw would work better. (Allen wrench)

Click to expand...

I won't get a chance to research this until Wednesday, but this sounds like a heck of a good remedy for my issue.
I could certainly hold an unaltered nut with the open end wrench (it won't turn that close to the horn tube anyway), while I spin the socket head bolt with the allen wrench.
You guys are awesome!
Thanks,
Tom

Can you even find a capscrew that doesn't have full-length threads. You need an unthreaded grip portion through the 2 horns.

aerhed said:

Can you even find a capscrew that doesn't have full-length threads. You need an unthreaded grip portion through the 2 horns.

Click to expand...

Good question. Made me do a quick search before I do my success dance. Innitial search was pretty grim, but then I found this. I'll have to call them this week to see what works in place of the AN4-14A Bolt.

http://www.gen-aircraft-bolts.com/

FYI, the MS21042 nut is an approved replacement for the typical AN nuts called out. The approval is on the MS21042 specification itself.

http://tinyurl.com/o5a7lys please see page 2, note 4.

Dave

OK, let's be precise here. The engineer says that the glass is exactly twice as big as it needs to be.

Limited Space bolts and nuts

You could replace the AN bolts with the 12-point reduced head bolts and nuts, which permit a smaller socket to be used, providing clearance:

Bolt: MS21250 -04XXX where XXX is the grip length in 1/16th inches. This will eliminate that problem cause by socket head bolts: full thread or insufficient unthreaded shank for the application.

Nut: M93-4 (also known as NAS1804-4)

These bolts are expensive, but could solve your problem. They area available from Coast Fabrication www.coastfab.com.

May I suggest you locate a highly experienced welder who can fill-in both the holes so you can start again? This would damage the powder coat but immediate cleaning, priming of the steel, and protective paint would mitigate that for now. In the future, you will more likely feel like making new elevators....

Good luck!

Get a NAS1351-3-XXP socket head cap screw. It is a 150ksi where the AN3 is 120ksi (as I recall). XX would be the grip length. Genuine Aircraft or Aircraft Sprice carries them. Compair the two specs to be sure you get the same grip length (part without threads).
Scott

Vans plans

Unfortunatley you will find it is far from the last time that Vans plans are lacking.
I can begin to tell you how frustrating it is to come up against so many areas where the plans have changed but not shown on the drawing, or making a part exactly per the plans and they don't fit. Two small examples are NO nut plates installed by Vans ( or even an instruction for you to do it) on the fuselage for installing the Horiz stab and also on the end of the flap for the control rod.
A few extra minutes from Vans, hours for the builder.
I've have spoken to them many times that they should have an honest quick build manual, so you don't have to go thru all the **** of the slow build when ou paid the extra money for the quick build ( no such thing, faster build maybe)
Their response is ( tough !!)
The best defense is to get with someone who has built one or more, it will save you many hours and lots of frustration.
Just finished my 8a after just under 8 years, flies beautiful but I cant say it was fun.
Bad thing now is you can buy one flying already cheaper than you can buy the rest of the kit and then build it... Bummer !!!! Good luck

Something else that bothers me is the lack of information on what you should and shouldn't do, depending on whether you're going fuel injected or not.

It would have been nice, if in the directions to install the carburated version's boost pump doubler on the firewall, the manual said "Oh, don't do this if you're installing a fuel injected engine."

A bit more quality control on the results coming back from the QuickBuild factory would be good too. I've found a good number of rivets that should not have been set in the fuselage since they need to be set in assembly with parts that the builder will install. For me: 14 Forward top skin rivets along the longeron and a rivet on each side where the horizontal stab gap fairing will be riveted on.

Also, alternating holes have rivets set on the lower wing root rib & skin so that the non riveted holes will be match drilled through the overhanging bottom fuselage skin. Well, the QB factory riveted the wrong alternating holes, requiring me to drill one out on each wing where a pre-punched hole in the lower gap fairing matched that position.

Sigh.

Well, this thread is timely.
I was setting up to drill the same holes today and ran into a somewhat similar problem although I think not as severe. This is only judging by eyeball because I have not actually drilled the holes yet but my left elevator horn I think will be just fine, the right one will be tight. I think the washer will just start to impinge on the radius made up from the weld. When I first fit the elevators up the crowding was worse so I ran both the rod ends on the right elevator out another turn to the 7/8" max called out on the plans. As it sits now the left elevator rod ends are both at 13/16" and the rights are both at 7/8" but the right horn hole will still be a little tight to the weld. I have an email in to Vans's for their opinion.

Out of curiosity, how many of you are seeing a difference in the angle of the two halves of the elevators relative to the horizontal stab. I have slightly less than 1 degree difference between the two elevators with a matched horizontal stab.
Opinions on effect? There just isn't any guidance in this section of the plans on how close they want them to be.