Location of front and rear wing-attach fittings

[Bird]

Re: Location of front and rear wing-attach fittings

I may be lost here also.
I just measured the 3 wings I have that are uncovered and this is what I found.
In the 13 rib wing starting at the root working outward measuring end to end all start with 30" with the following 1 thru 6, 4/16--4/16--4/16--4/16--2/16--4/16.
In the 15 rib the only difference was the 2nd position that was 30 5/16 and I can't figure that one out might be just me.
I didn't find any other size basically just the 2 sizes but I can't justify that 1 in the 15 rib wing

[8708]

Re: Location of front and rear wing-attach fittings

Well, I may have led all of us down the wrong path.
We hung the wings from the roof of the hanger, got the front attachment fitting to line up and pinned it and then lifted up on the wing and amazingly the rear fittings slid into place!
I guess my mistake was not taking into account the diheral and the angle of the wing as it meets the fuselage. Although I would have sworn it would not have fit.

I apologize for getting everyone out making measurements, etc. I hope no one had to go out of their way too much. I certainly am thankful for having such a great forum to turn to!

Unless anyone objects I would like to ask Rob to close the thread.

Thanks to all!
Jay

[Larry Lyons]

Re: Location of front and rear wing-attach fittings

Just my 2 shillings but this thread has brought out info that needed to be known. Larry

[Robert Lees]

Re: Location of front and rear wing-attach fittings

No need to close it...it's all good info.

[8708]

Re: Location of front and rear wing-attach fittings

Hi Rob,
That sounds good. I did not want to mislead anyone with my mistake on the wing fittings.
Thanks!
Jay

[Forrest Barber]

Re: Location of front and rear wing-attach fittings

The main thing is that the center of front spar to center of rear spar is of course 31" . Conversely the center of front wing attach to rear wing attach is 31". If you check the drawings you will see that most dimensions
are + or - 1/8th .....
The 31 in is used for all trammeling of wings and checking the top fuselage sub assembly for dimension & squareness . The whole top of fuselage is a sub assembly that came out of a jig that was perfect..... same with the forward end of fuselage and the whole side of the fuselage , these assemblies where then put into the main frame jig and out came a nice fuselage. There were three main frames in 1946; Mrs. Feris got the worst of the three we think the best one disappeared around 1958-60 over in PA.
Hers got sold with the factory stuff ; then MODIFIED to build the F-22 fuselages; what a mess! Back to building my ARK bye Forrest

[Guest]

Re: Location of front and rear wing-attach fittings

The main thing is that the center of front spar to center of rear spar is of course 31" . Conversely the center of front wing attach to rear wing attach is 31". If you check the drawings you will see that most dimensions
are + or - 1/8th .....
The 31 in is used for all trammeling of wings and checking the top fuselage sub assembly for dimension & squareness . The whole top of fuselage is a sub assembly that came out of a jig that was perfect..... same with the forward end of fuselage and the whole side of the fuselage , these assemblies where then put into the main frame jig and out came a nice fuselage. There were three main frames in 1946; Mrs. Feris got the worst of the three we think the best one disappeared around 1958-60 over in PA.
Hers got sold with the factory stuff ; then MODIFIED to build the F-22 fuselages; what a mess! Back to building my ARK bye Forrest

I am going to offer a second opinion here (see red above).

The main thing isn't that the spar center to center distance is 31" for the length of the wing.

Rather than that the main thing is that the spar center to center distance is the same as your fuselage fitting center to center distance for the length of the wing.

That way you don't have have those distorted spars at the root where the fitting got forced together by deforming wood.

I have seen that more than once.

For example the distance might be 31-1/16" from center to center on your fuselage fittings so set your wing to fit it.

Make it so the wing fits on nicely. The wing spar struss/frame assembly will not be effected strength wise by that 1/16" in the example I made.

Also their is the tolerance that Forrest mentioned that would allow this too.

I put the wing on the fuselage prior to covering in order to get this fit right.

In my opinion its too important to be left to a ruler alone but must be put in place to verify it fits.

Dave

[Forrest Barber]

Re: Location of front and rear wing-attach fittings

correct , out in the field the fuselage fittings may have moved by repair or rework. From the factory right out of the jig that dimension is right on.
Just have the spars parallel as noted . Here in Allaince we always tried to return the fuselage fittings to the correct measurements. I get a lot of calls about parts not fitting from one ship to the other. This is usually due to repair out in the field.

[Guest]

Re: Location of front and rear wing-attach fittings

correct , out in the field the fuselage fittings may have moved by repair or rework. From the factory right out of the jig that dimension is right on.
Just have the spars parallel as noted . Here in Allaince we always tried to return the fuselage fittings to the correct measurements. I get a lot of calls about parts not fitting from one ship to the other. This is usually due to repair out in the field.

kinda like the way guns were before 1900!

[Robert Lees]

Re: Location of front and rear wing-attach fittings

THREAD DRIFT WARNING!

kinda like the way guns were before 1900!

We all complain about quality control, quality systems, etc, but as Dave implies, it was the mis-match between guns & ammo (particularly during the Great War) that led to the first Mil Spec (shells have to meet certain dimensional criteria, to match those of the guns).

This in turn led (in time) to quality standards, the NPL, MS series, AN, BSI, ANSI, etc.

Not that we should forget the likes of Whitworth (much earlier, 1841), who's design standards are still in use today...for example, all camera tripod mounting threads are 1/4 Whitworth threads.


Please forgive the thread drift.

[Hank Jarrett]

Re: Location of front and rear wing-attach fittings

Just a tiny bit more drift. It is my understanding that the Japanese made the bore of their rifles before WW-II just slightly larger than the allies so that captured ammunition could be chambered in their weapons, but if Japanese ammo was captured it couldn't be used by us.
Don't personally know if this one is true, but an old Pacific Vet told me that it was.
Hank

[Guest]

Re: Location of front and rear wing-attach fittings

I tried to google the National Screw Thread Standardization Act but did not find.

It was around 1910 and essentially brought thread drift to an end in the US.

[Robert Lees]

Re: Location of front and rear wing-attach fittings

[Pearson]

Re: Location of front and rear wing-attach fittings

So, all you great thinkers out there, are the spars supposed to be 31" apart all the way out to the tips? Does this mean that the compression tubes have different lengths only to offset things like the attach fittings and doublers.

I have not disassembled my wings. But I have been watching this thread with great interest.

[Guest]

Re: Location of front and rear wing-attach fittings

read the posts the answers are there