Am I jinxed?

I swear, I think my wing kit - specifically my spars, were made after a liquid lunch was served to the hole-punch operator.

11th rib outboard, the predrilled holes for the spar and waffle plate are horizontally off by 1mm! Clear as day, for anyone who cared to look. So, which is correct? Waffle plate or spar? I took a few measurements, decided the spar was ok, redrilled (so the waffle plate holes are oval at rib 11) and moved on, figuring an extra half-length will be required to fill the hole. No biggie.

If only.

Wing jacked up, level, square spar, not twisted, upper outboard wing skin holes drift out of alignment while moving inboard, in just about the same place and amount the spar/rib holes are out. Great!

Has anybody else had these kind of issues?

My plan right now is to do my best to get this skin aligned, I'm making an extra TE spar jack, hoping I can juggle everything and make this my mistake, but I'm not hopeful.

If that doesn't work, I'm going to get permission to drill and dimple these as -4's, which is the only way I can see not having half-moons of unsupported material, etc.

I bet the fitting of the outboard LE is going to be a complete fiasco too.

RIck 90432 - staring at wings

Stop and call Vans

If you have this thing level, square and plumb, the skis should line up perfectly if you did a decent job on flutting and drilling your ribs to the spar.

Mine fit perfectly. It is possible that your spar is not built properly. Before going forward and ruining your skins and ribs, I would call Vans and get the low down.

Rick, Check a few things:

1 Make sure your flanges are 90 degrees, if they are see #2

2. Make sure the flange on the end of the rib that meets the spar is bent in the right spot. If the flange is to wide the holes in the skin will be above the holes in the spar. If the flange is to narrow the holes in the skin will be below the holes in the spar. Even though it may be a perfect 90 degree angle on the flange of the rib it most be located in the right spot or it will move the location of the holes in the rib in relation to the skin. Had a leading edge rib like this and bought a new rib and all was well.

3. Cleco the skin first to the spar using plenty of clecos and then to the ribs

Clarification

Guys, thanks for the hints - but I think I may have been unclear about what is happening. Per the instructions - inboard skin + walk reinforcement - no problem. Start on outboard skin - generally I've been positioning at the overlap, then supporting by cleckoing to the spar with 3 or 4 at mid span - EXCEPT the holes don't match on the outboard past 1/3 of the way out. Simply, one hole matches, the next does not, nor do the remaining outboard holes. I can reverse this if I start with the mid-skin rivets, then the OB skin won't line up with either the inboard skin overlap or the 1/3 inboard holes. It's not a progressive moving out of alignment, like you'd expect from a warpage condition.

Regardless of how I start, the ribs have enough flex to square up, and the TE aligns just fine. I have not tried the bottom skins yet, nor the LE skin - but I'm expecting the same situation.

Is this more clear? I'm just not in the mood to go through the whole image hosting nightmare right now, or I'd post a pic.

Rick 90432 wings

I think what you are trying to say is the holes don't line up side to side as if the spacing between the holes length wise along the spar or possibly the skin is not correct. Do you have your other spar or skin to compare it to? Left and right skins are interchangable if you haven't drilled them yet if I remember correctly. Try your other skin on this spar or just lay the two skins on top of each other and see if there is any difference.

I don't remember anymore but it may be important to make the ribs face the correct way as shown on the plans.

Ribs facing wrong way or out of order. Every time I have thought the parts were screwed up, it turns out to be "operator error"! These parts are designed and punched out by computer. Small chance they are flawed.

Keep 'em coming!

Guys,

Paul, you've got it. Skins match L&R. This was not an issue with L wing, only right(left is already fully drilled, disassembled). Triple checked part numbers and rib direction - ok. Conclusion: R spar is different.


And while I think 3-D cad is a great thing, my wing ribs have a mis-punched hole - a known problem for the first 500 or so -9 wing kits. And on misformed rib rear rib. And three LE ribs bent crooked.

It looks like this, of you pardon the ASCII art:

Root <---- O O O (O (O (O ----> Tip

At or about the 11th rib, the offset happens, and does not vary out to the tip.

Van-o-gram tomorrow.

$5 they say one of two things: drill it and be careful of offset, pretend like it's not there, or drill it for #4's at where mismatched.

Rick 90432

I read somewhere (but don't remember where) that this is a common problem on the 9 because the spar is too long to be punched all at once, so it is repositioned in the machine before doing the outer holes. Sometimes it's not aligned perfectly but usually only slightly out like mine were. 1mm is excessive!

Measurement

Guys, I've actually measured the offset, and it's 0.031" It exists for the upper and lower outboard skins, as well as the leading edge skin. That would make 172 holes that don't match up along the spar. It's unlikely a -4 will fix this - you could if you could jig-drill for position (of all 172 holes, through both skin and spar) but I don't know how to do that - yet. I don't know if c/s the spar flange for a -4 dimple is a good idea either.

Waiting on Van's response. I've got my own, 'optimized customer satisfaction' version, and I'm thinking about pushing it, we'll see what they say. I'm in a Monday mood.

If anybody wants a copy of the pic, pm me with an email address. It's kinda obvious in the pics. Basically, the on-center spacing is 1.134" for the holes, except for one at 75 3/4" out - it's 1.103" - then it resumes 1.134". The 'repositioning on the punch press' sounds like a reasonable cause!

Rick 90432.

rjcthree said:

Guys, I've actually measured the offset, and it's 0.031" It exists for the upper and lower outboard skins, as well as the leading edge skin. That would make 172 holes that don't match up along the spar. It's unlikely a -4 will fix this - you could if you could jig-drill for position (of all 172 holes, through both skin and spar) but I don't know how to do that - yet. I don't know if c/s the spar flange for a -4 dimple is a good idea either.

Waiting on Van's response. I've got my own, 'optimized customer satisfaction' version, and I'm thinking about pushing it, we'll see what they say. I'm in a Monday mood.

If anybody wants a copy of the pic, pm me with an email address. It's kinda obvious in the pics. Basically, the on-center spacing is 1.134" for the holes, except for one at 75 3/4" out - it's 1.103" - then it resumes 1.134". The 'repositioning on the punch press' sounds like a reasonable cause!

Rick 90432.

Click to expand...

This is not an ideal solution but it may reduce the # of holes to adjust. Try clecoing the outer skins from the outermost rivet holes first. I.e., hang the outer skins from the outboard end towards the inboard and the inboard skins from inboard to outboard. Then just look at the overlap region and correct that.
May not work at all...

-mike

Inboard vs outboard

Mike, thanks for the idea, and you're right, it would decrease the number of rivets to about 120, plus the double rivet line at the seam between inboard and outboard skins.

Edit: I don't know if it would work, actually - the skin would be off inboard, and all the TE spar holes, which would have been located by the inboard skin, would no longer match the outboard skin - unless I warped the snot out of the panel.


Rick 90432

update 3/28

I'm a little disappointed with the response I've gotten so far from Van's on this issue. My email was sent early Monday morning. Monday evening I called during tech support hours, and was told to wait for an email response - such that they wouldn't have two people working my issue. Ok, fine.

Tuesday: no email. I call during evening tech support hours, and get told 'it's been bumped up to engineering', and that they will call me back, they take my number, and . . . . no call.

Wednesday(today): No email, no call. Evening hours, I call again, get my number taken again, and don't get a call. Van's is now closed.

In summary, I've been dead in the water since Friday, and I'm starting to get cranky. Am I wrong? Seriously, tell me what you think.

Secondly, I've been rattling my brain for a solution to this. A new spar is the only solution that I feel safe with at this point. Drastic, but I need to send my center section in to have my QB fuse built, so they should be able to match-ream the new spar. This appears to be a straight quality issue, the parts I rec'd, and put time into (platenuts) is unsuitable. It should be replaced.

Yes, I'm cranky. I am sorry about that. I don't think I'm wrong, but I'll listen to you guys if you give me your thoughts.

Rick 90432

Just a bit of advice from a ol feller that deals with the public everyday.............The squeaking wheel gets the grease!.........call um every 5 minutes and you'll get your answer from Van's.

Ahhh, relief

Matthew, you're right. I got sqeeky, I got help.

I finally talked to Ken Kruger, in engineering. We talked, I took some additional measurements, and Van's is going to punch custom skins for me - upper, lower, and LE. Lead time is not yet determined.

He said they don't like to mix and match spars and center sections, although it's been done with no problem. It sounded like it may be easier(cheaper?) to custom punch a set of skins than send a new spar. They have done this for another builder with the same issue.

Either way, I was told NOT to drill to #4.

Things are looking up.

Rick

Rick,

Yeah, i would not despair too much. A custom skin sounds like a very interesting solution. You have to figure that Van's has pretty much seen it all, and they are in the best position for sorting out a solution.

I had a similar kind of QC issue on my rear spar. A flange was not bent accurately, causing my skin to rear spar holes to be out of alignment by 3/32" for about 20 inboard holes. It too was suggested to me to drill to -4 or even have new parts sent.

It's really frustrating when my left wing went oh so beautifully, then to have something so frustrating come up on the right wing.

Matchholed parts are wonderful when they are perfect. They are **** when it is not.

Jae

Spoiled?

Jae,

You bring up a good point. Are we spoiled by the match hole parts? I'm sure the folks who have built other things laugh at us and our prepunched holes . . . .but you have to admit, it's a beautiful thing!

Skins are being punched/shipped Tuesday.

One of the reasons we're going this way is because my measurements, while retentive, are good, and match what they should be by design, so we've got confidence. Otherwise, Ken was going to have skins punched with the offending holes blank, and I would back-drill through the spar flange.

Ken Krueger is one of the nicest people on the planet, by the way.

Rick 90432

Update - the joy and the pain

If you've been following my saga of mismatched spar holes, the good news is the custom skins Ken had made are perfect. I could not be happier with this, unless it could have been avoided in the first place.

I have found another mismatch in my right inboard bottom skin, and it's plain as day - a mispunch. If you try to draw a line down the rivet line, it deviates at the skin overlap about 2/3 back, all the way to the rear spar. Similarly, from the skin to rear spar holes mismatch from the outboard side of the middle spar bracket to the end of the inboard skin. Not by a little, eyeball guess is at least 0.06 - it's more than 2/3 of a hole mismatch. Basically, of you take the bottom left corner of the skin, and shift all the holes in just that section outboard by 1/16", you've got the picture.

I may hack this one. I'm thinking -4's and a backing strip.

This is why I'm ordering a QB fuse.

Rick 90432 - kinda working on wings

Last of the saga

Ken Kruger confirmed my new skin mispunch, and a new skin is on the way. He also confirms that I'm jinxed. Honestly, the left wing was assembled, drilled, disassembled in about 3 days. The right is going on 9 weeks now. Grrr.

And yes, I am getting other little things done - like getting an engine-parts order together!

Rick 90432

I just read the thread, but it's good to know that Van will make situations right. I'm sure "mispunching" a skin on purpose to get it to fit you wing was not a small task, but they did it.

Yukon said:

Ribs facing wrong way or out of order. Every time I have thought the parts were screwed up, it turns out to be "operator error"! These parts are designed and punched out by computer. Small chance they are flawed.

Click to expand...

I don't share your confidence. Sometimes Vans prepunched holes are way off.

The matched hole punching on the Trumpf machine is pretty good on the Vans kits. But where Vans come unstuck is when they take the punched sheet out of their precision Trumpf machine and start folding it in a sheet metal press brake as a secondary process. If they don't have the bend placed to the same accuracy as the punched holes (very difficult to do)....then the punched holes don't align.

This is very common on the pre-bent trailing edges of elevators, flaps and ailerons. When they don't get the fold in the right position the holes in the skin don't match the holes in the ribs.

Bob Barrow
RV7A Finishing