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770 side skin fitting problem

Andre Kerstens

Andre Kerstens

Member
My aft and center fuse pieces were mated together today (yeah!), but a good start of the day has turned into bad side skin fitting problems. No matter if I start cleco'ing from the front or from the back, the skin doesn't line up with the rivet holes by sometimes up to 3/4 of an inch. Pushing/pulling on the tail doesn't bring anything as well. Has anyone else had such a tough time with the 770 skins as well? Anything I should try? I'll call Vans tomorrow as today they are closed.

Have a look at the pics on my builders website to see what I mean (you have to scroll down a bit for the side skin fitting problem).

Thanks!
Andre
 
Andre Kerstens said:
My aft and center fuse pieces were mated together today (yeah!), but a good start of the day has turned into bad side skin fitting problems. No matter if I start cleco'ing from the front or from the back, the skin doesn't line up with the rivet holes by sometimes up to 3/4 of an inch. Pushing/pulling on the tail doesn't bring anything as well. Has anyone else had such a tough time with the 770 skins as well? Anything I should try? I'll call Vans tomorrow as today they are closed.

Have a look at the pics on my builders website to see what I mean (you have to scroll down a bit for the side skin fitting problem).

Thanks!
Andre
Click to expand...

Andre,
Do you by chance already have the fwd lower longerons drilled to the center section and the lower firewall weldments?
If so, it is forcing the firewall to be at the wrong vertical position. The F-770 side skins should be what establishes the vertical position of the firewall. You need to cleco the skins to the center section and then let the firewall move so that it aligns with the skins.
 
Hi Scott,
no, the firewall has not been mounted/drilled yet. To have as much flexibility as possible I also removed the bagage skins and all the cleco's that hold the bagage ribs to the 706 bulkhead. Didn't help :-( I have no idea what's going on here, as it seems most people just cleco these on without problems.
 
Andre,

Try moving the back of the aft section up and down versus forward and backward. If I recall correctly and maybe I don't, ( I am getting older) seems we had the same issue. Make sure you have the double row where the two parts join lined up.
 
Same Problem

I thought I was looking at the post I was getting ready to write tonight. I was mating my RV7 fuselage also today. My side skins look exactly like yours. I guess we should have a conference call with Vans.

Mark
Fairmont, MN
 
RVRC said:
Andre,

Try moving the back of the aft section up and down versus forward and backward. If I recall correctly and maybe I don't, ( I am getting older) seems we had the same issue. Make sure you have the double row where the two parts join lined up.
Click to expand...


What Robert said... raising the tailcone just behind the 706 bulkhead should line things up better for you.
 
Its must be something in the air, as I just put my 7A side skins on only about 4 hours ago. I started around the wing spar cutout, nice and easy. When I got to the aft section, I had the same fault. I had to move my sawhorses around. I had to lower the Tail so that the holes would move FWD toward the side skin. I dont think Vans will be able to help other than advise you to move things fwd/aft or up/down.

I just went out and had a look at the longeron to firewall gap. Mine go past the rivet hole on your webpage and stop 16/32 from the end edge on the side skin end/firewall.

Did you do the ADD 1" to tape measure thing and forgot to ADD it at the end, as IT looks to be about 1" short. I would call Vans on the longeron problem.
 
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Wow, that is kind of amazing :) Maybe the first who gets Vans on the phone can let the other know what they said... think we have ended up with side skins from a bad batch?

Andre

Mark7986 said:
I thought I was looking at the post I was getting ready to write tonight. I was mating my RV7 fuselage also today. My side skins look exactly like yours. I guess we should have a conference call with Vans.

Mark
Fairmont, MN
Click to expand...
 
I wonder if the longerons will move forward 1/2 inch more when I get those holes to line up. I don't understand how they could end up to short as I re-measured before bending the left longeron this afternoon and they are exactly the length Vans specifies on the plans (173 7/16 I believe). Wish now that I hadn't cut them yet I guess. Let's see what Vans says.

Thx, Andre

Jamie Aust said:
Its must be something in the air, as I just put my 7A side skins on only about 4 hours ago. I started around the wing spar cutout, nice and easy. When I got to the aft section, I had the same fault. I had to move my sawhorses around. I had to lower the Tail so that the holes would move FWD toward the side skin. I dont think Vans will be able to help other than advise you to move things fwd/aft or up/down.

I just went out and had a look at the longeron to firewall gap. Mine go past the rivet hole on your webpage and stop 16/32 from the end edge on the side skin end/firewall.

Did you do the ADD 1" to tape measure thing and forgot to ADD it at the end, as IT looks to be about 1" short. I would call Vans on the longeron problem.
Click to expand...
 
Andre,

This looks OK to me... I remember it being a challenge to make all fit.

1. Check you have the right parts and the dimensions are correct - I am sure you do.

2. Cleco the side sheets to the "Golden Bulkhead" first. Now cleco to the bukhead supporting the rear spar. This will make your seating area take the correct shape and the easy holes are lined up. Now move around the rear section to fit. Some things may need minor alignment to fit.

3. Take another look at the plans and be sure you have the double rivets lined up in the correct location/position of the aft bulkhead correct. You have to drill at least one of those rows of rivets.

Do not be too cautious as you may have to push the parts around a bit to fit. If it will not go together then you have the wrong parts or trying to make them fit where they should not. Double check plans. Have you put the correct side skin on the correct side?

Your Longerons look suspicious if they are not the correct dimension. Double check and or remove them from the equation. You either have the skins in wrong position or longeron too short.

Richard
 
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Side Skins

I looked at the numbers on the side skins and they looked interchangeable. They are the same number, no left and right. I'll try swapping sides Wednesday.

Mark
Fairmont, MN
 
Andre,

I can't get to your web site to check the photos right now, but make sure you have your spacers in with your temp bolts to square up your 704 bulkhead. If the forward side of the bulkhead sits higher than the aft side it will throw the side skin off.
 
OK. Good news. I thought I give it one more try with the help of a neighbor before calling Vans and guess what, we managed to line up the holes in the 706 bulkhead and skin enough to get some cleco's in. I must say I never expected to need so much excessive force to do this. We had to lift the aft fuse at the 706 bulkhead by more than a foot!

Anyway, for those who are still trying (Mark, Jamie) keep on going at it and get some help. I'm sure you guys will be able to get this done too!

And guess what, my longerons are now nicely lining up on the front; half an inch between the end of the longeron and the end of the skin. I might even have to trim them a little.

Cheers and thanks for all the replies.
Andre

PS My website is down at the moment. I'm back up soon again I hope.
 
OK. Good news. I thought I give it one more try with the help of a neighbor before calling Vans and guess what, we managed to line up the holes in the 706 bulkhead and skin enough to get some cleco's in. I must say I never expected to need so much excessive force to do this. We had to lift the aft fuse at the 706 bulkhead by more than a foot!

Anyway, for those who are still trying (Mark, Jamie) keep on going at it and get some help. I'm sure you guys will be able to get this done too!

And guess what, my longerons are now nicely lining up on the front; half an inch between the end of the longeron and the end of the skin. I might even have to trim them a little.

Cheers and thanks for all the replies.
Andre

PS My website is down at the moment. I'm back up soon again I hope.
 
Great news andre !

I had the same problem to start with as you did, but all that was needed was to move things to get it in the correct position. I even had time to drill the arm rest that day.
I will have to keep track of everyone that sent a reply as we are all at the same point, the race is one !!!

P.S doesn't it look good, all together now, shame we have to pull it all apart again soon.
 
Yup, let's all plan the first flight at the same time ;)

I just drilled the armrests as well. I've also started to modify the 623 rib for the steps. Next the bend in the 770 skins...

Cheers
Andre

Jamie Aust said:
Great news andre !

I had the same problem to start with as you did, but all that was needed was to move things to get it in the correct position. I even had time to drill the arm rest that day.
I will have to keep track of everyone that sent a reply as we are all at the same point, the race is one !!!

P.S doesn't it look good, all together now, shame we have to pull it all apart again soon.
Click to expand...
 
Thanks for the encouragement. Tomorrow is my day to work on the fuselage. Hope I can find someone to help. I'll let you know how it goes.

Mark
 
How about that!! Let it set for a couple of days and it went right together. I guess what they say about walking away works. It looks good, did my curves, drilled all longerons, installed firewall and forward bottom skin clecoed on.
Life is Good

Mark
 
Think you're right. The second install (after the conical bends) went so much smoother. I'm drilling the longerons today, but have a question: where the longerons have a cut in them to fit around the 711 bulkhead bars they do not sit completely flush with the edge of the skin because of the top of the bulkhead (see this image). Is that a problem or can I drill the longerons safely here?

Andre

Mark7986 said:
How about that!! Let it set for a couple of days and it went right together. I guess what they say about walking away works. It looks good, did my curves, drilled all longerons, installed firewall and forward bottom skin clecoed on.
Life is Good

Mark
Click to expand...
 
770 Side Skin

I guess you've already answered the question/solved the problem, but when I called Van's 6 mos ago with the same question, they basically said keep moving things, get out the ice pick and clecos and it will go......it did.
 
Andre Kerstens said:
Think you're right. The second install (after the conical bends) went so much smoother. I'm drilling the longerons today, but have a question: where the longerons have a cut in them to fit around the 711 bulkhead bars they do not sit completely flush with the edge of the skin because of the top of the bulkhead (see this image). Is that a problem or can I drill the longerons safely here?

Andre
Click to expand...

We talked about this at length and decided it wasn't a problem, but rather was a construction sequence "issue" (you build the complete 711 builkhead first, including the top part, then later set the longeron on it...if we had held off on putting that top angle piece on, then we could have filed down the builkhead just a fraction of an inch and the longeron would have been pefectly even with the skin all along the fuselage). As it is, it gets covered by the top skin and such, anyway, and it's just a tiny fraction of an inch above the skin, so shouldn't be an issue. In any case, there's nothing you can do about it, anyway...build on!
 
770 revisited

First, a thank you. For all you folks out there that post your problems and all you other folks that add your solutions. And to Doug for hosting the whole process.

I am in the process of joining my aft and center section. A long story short, it would not align and the longeron seemed too short. I pushed and pulled and swore .... alot. Finally I did what any sane builder does. I checked vansairforce. Here it is, the EXACT problem I was facing with the solution.

I do not know how many times this has happened or how many times problems were avoided by spending time reading threads. Too many to count.

Thanks again.
 
+1. I joined the tailcone and center sections on my -7 last night and am clecoing on the side skins this morning. Had exactly the same problems, did a VAF search, and found this thread - what a stress saver!

Thanks everybody and happy 2012!

Dave

sahrens said:
First, a thank you. For all you folks out there that post your problems and all you other folks that add your solutions. And to Doug for hosting the whole process.

I am in the process of joining my aft and center section. A long story short, it would not align and the longeron seemed too short. I pushed and pulled and swore .... alot. Finally I did what any sane builder does. I checked vansairforce. Here it is, the EXACT problem I was facing with the solution.

I do not know how many times this has happened or how many times problems were avoided by spending time reading threads. Too many to count.

Thanks again.
Click to expand...
 
+2 Spooky how many are fitting Aft and Center Fuse Sections

I was at this very point yesterday myself; same results. Surprise, worry, then wondering what was wrong. This was followed by a visit to VAF finds a BUNCH of people in the same spot. I did have some preliminary luck getting clecos into the skin overlap by raising the aft fuse, but because the fit seem to be way off, I thought there was a problem. Evidently these skins need to be VERY taut (to prevent oil canning, maybe?)
 
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