horzizonal stabilizer build question

[rockwoodrv9]

OK, now that I have worked for a few hours on my project I was starting to consider myself an expert. Then I got to clecoing the skin on the HS. Everything was great until I got to the angle ribs on the end ? HS 905, HS 905. I am not a mathematician, but with the ribs going at an angle, the holes will not line up with those on the skin. My questions are:

1. Do I do whatever it takes by stretching the rib flange at the spars to make the holes line up?
2. Do I drill new holes using the skin as the pattern?
3. Is there another option?

Another question I have is about the cleco?s. When I look at photos of other builders, every hole has a cleco in it. Is that necessary? What advantage is there putting one in every hole? Since so many do it, there must be a good reason that I can?t see ? even after several hours of assembly experience!

I am enjoying the build. I think the plans and the manual could easily be improved and made much easier to understand. Im sure as I get further into the project, I will understand the drawings better, but I know if my engineers ever gave me drawings as incomplete and unclear, they would be back at the CAD program.

Thanks for the help. I appreciate it.

Rockwood

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[fatherson]

Asking questions was definitely the right thing to do, Rockwood. I'm like you, and have to overcome my tendency to barge right ahead until I face an insurmountable roadblock. Here's some answers from one beginner to another, so don't take them as gospel:

1. Do I do whatever it takes by stretching the rib flange at the spars to make the holes line up?

Not sure what you mean by "stretching" here, but follow the directions about straightening the flanges using a fluting tool. My general advice is "slow way down", especially at the beginning. Take a class. Get some local help on site. Read the plans once and again (for example, are you certain your flanges are facing the correct direction?)

2. Do I drill new holes using the skin as the pattern?

Definitely not. On the pre-punched kits, you shouldn't need to do that.

3. Is there another option?

This question is kinda answered by your later one. A cleko in every hole may not be necessary (but might help sometimes, like on the trailing edge wedge), but a cleko every other hole when things aren't fitting will often pull everything into alignment.

I'm almost certain you were kidding about the "expert" feeling after a few hours. I sometimes feel less capable even after many hours of learning on the job.

Have you built the two practice kits? They're definitely one way to break cheap parts before you attempt expensive ones.

--
Stephen

 

[cln1owner]

Granted, it's been a couple of years since I've even looked at my HS, but those ribs look backwards to me... the web of the rib should be inboard and the rib flange should face out towards the skin edge.

 

[rockwoodrv9]

was able to get the holes to line up

With some gyrations, I was able to get the holes to line up. The fit of the shim and the doubler on the spar along with the rib being positioned at an angle, it had just stretched a bit. With a little pushing and using a nail in the holes to help, it worked out fine.
As for being an expert after a couple hours, I thought everyone felt that way!

I did build the tool box and made a few other things around the house. i picked up some AL in Denver last week and have been experimenting on it. I picked up 1/8 and 3/32 bits and forgot to get the #30-#40 bits to ream out the holes, so I am assembling what I can until Thurs when the bits will be here. I don't have a hand squeezer yet, but I do have the DRDT-2 and that makes a great dimple.

One thing i need is something better than a finish nail to line up the holes. I bought a Bostitch 1.16" pin punch. That lasted about 3 holes until it snapped. What are you using to find the holes and align them if needed?

Thanks for the help.

 

[rockwoodrv9]

correct

Granted, it's been a couple of years since I've even looked at my HS, but those ribs look backwards to me... the web of the rib should be inboard and the rib flange should face out towards the skin edge.

I did notice that when I was aligning them and flipped them around. Thanks for noticing! That helped a bit with the hole alignment, but adjusting the shil - rib angle made it fit. thanks

 

[Mike S]

The more clecos you have in the structure, the better aligned things will be ---usually. They keep the skin pucker at a minimum, but are heavy and too many can distort an assembly unless it is supported well, or fully clecoed

A trick you could use is to put in 3 or 5 in a row, and then remove the center one drill that hole out, and then leapfrog down the line, keeping at least one cleco on either side of whatever hole you are working on. In the area you have already match drilled, just use enough clecos to keep things from falling apart.

As to the angle rib thing, I have not heard of someone having that issue before, so I would tend to suspect you have something wrong. Either the correct rib installed incorrectly, or the wrong rib in the first place.

Good luck, carry on

 

[rockwoodrv9]

clarify

Granted, it's been a couple of years since I've even looked at my HS, but those ribs look backwards to me... the web of the rib should be inboard and the rib flange should face out towards the skin edge.

I tried the ribs both ways to see if they fit. I am about ready to get an air cleco gun after the assembly, tear down, twice! The picture is the second time with the ribs reversed. I pealed off all the plastic and that made the difference.
Everything fits fine now. I measured the holes in the skin and Vans allowed for the length change because of the angle.

 

[bird]

just a note

to remember, on assembly always check carefully on the drawings, especially with ribs. In general, the outboard ribs and inboard ribs usually install with flanges outward. The reason is for access to rivet them, some other parts during the build are like this also. When you get to the wings be especially careful as to which ribs go where. They look very similar but are different. On the wings you will be installing some ribs marked L/H on the right wing and vice versa. Pay close attention to this by double checking on the drawings. It will save you a lot of trouble as you build. hope this helps.

bird

 

[Andrew M]

Alignment

I use a couple of sharp scribes to help align things. Also note that clecos fill the hole one way, but not 90 degrees out. The can be put in "narrow" and rotated "fat" before releasing to help pull in the direction you want. Using a cleco in every hole, chasing the alignment as you go is common around leading edges. As far as prints and instructions, I have found these to be more that adequate. However I also have 20+ years banging rivets. Just because I know what Vans is after doesn't mean everyone will. Many of us here are only to glad to help.

 

[Paul B]

slow down

As others have said, slow down and check the drawings very carefully. You don't want to install ribs facing the wrong way or the wrong rib in certain locations (it can be done).

Be very careful using a nail, punch or other prying tool in the holes. If you are using enough force to break a punch, you are distorting the holes. I have a couple of punches that I have ground down to use as line-up tools but I use these as a last resort. 90% of the time if things don't line-up it is because I am doing it wrong.

 

[krw5927]

Granted, it's been a couple of years since I've even looked at my HS, but those ribs look backwards to me... the web of the rib should be inboard and the rib flange should face out towards the skin edge.

Nate hit the nail on the head. Check your drawings VERY carefully before you proceed. The ribs in your photos are installed backwards (left ribs on the right side, and vice-versa). The flange goes inboard so that you can squeeze/shoot the rivets there with the skin on.

The holes will line up nicely when the correct rib is in the correct location.

 

[Don]

I don't think anyone has mentioned fluting yet. I know when I started building fluting seemed to be a black art. I could make rib holes line up with a little coercion. Then one night, about 6 weeks into the build (jet checked my log), and probably after reading Van's tips in the front of the manual, I happened to put two matched ribs back to back.

One rib was an 'L' and the other a 'R', and were oriented with the webs facing each other. The warpage caused by forming the flanges of the rib was obvious. here's a before picture:

and an after fluting picture:

It was a very modest 'ah ha' moment, but it was part of that "education" builders seek. I understood why some of the holes didn't line up perfectly but were close enough to wiggle-fit a cleco in to hold the rib in place. That's when the reason for fluting became obvious. A bit of careful fluting between the predrilled rivet holes flattened the ribs out almost perfectly.

It was quit surprising to me at the time, just how easy and obvious, purposeful fluting was to do. After that, when things didn't fit really well, a little tweak with the fluting pliers fixed the problem. Now as others have noted, there are times when things are not close to fitting and in my experience, 100% of time it has meant that I've assembled something wrong.

Have fun with your build.

 

[airguy]

I pealed off all the plastic and that made the difference.

Yup - there you go. Some of the tolerances on the pieces are close enough that even a few thousandths of an inch worth of the blue plastic is enough to cause trouble. Pull all the plastic off matching surfaces before fitting them up.

Also - as others have mentioned - if it doesn't fit with the prepunched kit, odds are about 99.95% that you've got it assembled wrong and need to take a breather and a good look at the drawings. I've only found ONE case of "truly bad parts from the factory" on my build so far, but I've had lots of those "It won't fit!" moments before figuring it out.

 

[RV9Ralph]

As a aid in lining up the holes, get an awl. It will help. I learned from an IA that gave me some guidance several years ago. But with this warning, if you have to pry too hard, you can booger up the holes (that's a techical term)
RV9Ralph
Livermore, CA

 

[aarvig]

Granted, it's been a couple of years since I've even looked at my HS, but those ribs look backwards to me... the web of the rib should be inboard and the rib flange should face out towards the skin edge.

I agree...those are backwards.

 

[rockwoodrv9]

yes

I agree...those are backwards.

Yes, they are backwards. I tried shifting them to see if I could get the holes to line up. My problem ended up being the plastic covering didn't allow the rib to sit tight against the shim. A measurement on the other rib confirmed the holes had been adjusted for the angle of the rib. It fits nice now. thanks

 

[Rivethead]

Why are you assembling with the plastic on?

 

[rockwoodrv9]

Im not now

Why are you assembling with the plastic on?

Im not now.

 

[airguy]

Make yourself a note in your plans - when you get to the fuselage and you are assembling the bulkheads in the far aft tail cone area, there are two bulkhead pieces that form the F-711 bulkhead that are riveted together and then riveted into the aft fuse - but the plans show them reversed. When you get to that point you will fight and cuss those parts, consult the drawings about seventeen times and fight and cuss some more - but the drawings really are wrong on that one. Reverse the orientation of the part front/rear, and they will fit MUCH better...

 

[rockwoodrv9]

lunch on me!

Make yourself a note in your plans - when you get to the fuselage and you are assembling the bulkheads in the far aft tail cone area, there are two bulkhead pieces that form the F-711 bulkhead that are riveted together and then riveted into the aft fuse - but the plans show them reversed. When you get to that point you will fight and cuss those parts, consult the drawings about seventeen times and fight and cuss some more - but the drawings really are wrong on that one. Reverse the orientation of the part front/rear, and they will fit MUCH better...

Thanks Greg, I owe you at least a lunch for saving me that bit of frustration! I enjoy your build site and look at it often. If you are ever in the Aspen area, I will make good on that lunch debt.
rockwood

 

[Rupester]

To the original question about clecos ...

When I took the Sportair workshop on basic metal skills (way back when I was an aluminum virgin ;o) the instructor said the basic guideline for drilling/riveting is a cleco in at least every other hole. I used that throughout my build with almost universal success.
My important discovery through the tailkit phase was that anytime something really didn't fit or holes didn't line up, it was ME doing something wrong or misinterpreting a drawing. Vans quality is so good, you'll rarely find an error on their part(s). There are many places where their instructions could and should be improved, but darn few instances where their materials or parts are incorrect or deficient. Many mfgrs could learn something from Vans quality control. But that's just my opinion ....

 

[rockwoodrv9]

Terry

You are correct. The problem was me not removing the plastic before assembly. I didn't think it would make that much difference leaving it on the spars - I was wrong. Then I spent hours taking it all apart and trying the ribs the other way, just to see if it worked. In my head, I figured the kit would not be drilled incorrectly, but I wanted to make sure. What bothers me is I wasn't bright enough to understand the thickness of 2 layers of plastic could put the holes off. I could make it work if I used a punch and forced it, but that just didn't seem right. After taking it apart and removing the plastic, it went together as it should. I guess working with wood all these years, I have to understand metal tolerances are different than wood.
Im making notes and if I find the time, will put the notes and draw them up in CAD and maybe send them to Vans. The drawings I have not been updated since 2001. I bet there have been some good ideas and clarifications that have come up in the past 10 years that would be nice to know now.
Have fun with your build.

 

[airguy]

This website is a goldmine of "been there, done that" - if you really think you've got a bad part or a bad drawing come here and ask the question before you start to modify parts or order new ones. It will save you a lot of time and frustration!