Tail surfaces - 109F versus 109E?

[Graham Boak]

Which do we do ? All of them, of course.

There does seem to be an unexpressed absolute lurking in this thread: that there was only one standard of fin/rudder for the E, and only one other for the F. Therefore manufacturing plans that do not match existing examples must be wrong. I do not know how many different rudders were produced during the life of the 109, but it is quite likely that one set of drawings will match a specific production batch, whereas another set of drawings will match a different batch. To produce dimensions from source A, and declare source B's different dimensions "wrong", you must be sure that they are referring to the same production batch.

In British terms, the same modification standard.

Anything coming from a flight test origin may be immediately suspect, as a non-standard test item.

[Crumpp]

There does seem to be an unexpressed absolute lurking in this thread: that there was only one standard of fin/rudder for the E, and only one other for the F. Therefore manufacturing plans that do not match existing examples must be wrong. I do not know how many different rudders were produced during the life of the 109, but it is quite likely that one set of drawings will match a specific production batch, whereas another set of drawings will match a different batch. To produce dimensions from source A, and declare source B's different dimensions "wrong", you must be sure that they are referring to the same production batch.

Well put and absolutely correct.

[pstrany]

Wow! I can see I should have been more precise!

The manufacturer's drawings I refer to are general layout, not for individual parts. I'm fairly certain that each sub-manufacturer would have received an extremely detailed set of drawings of each and every part they were to manufacture, but while I would love to have a set, I have yet to see anything like that.

So what I have to work with are overall layout drawings, 3-views (some very detailed) from various aviation books, and period photographs. While the drawings thus far posted are extremely helpful in terms of providing dimensional data, the drawings themselves do not seem to be intended to be an exact rendition of the outline of the various parts in question.

From a detailed examination of period photographs (of which most are from an oblique angle and thus of little use) I have found that indeed, even on the same model (like the Friedrich) there are differences from aircraft to aircraft in the exact outline of the aircraft (and so I also would assume the parts themselves to vary, though of course the differences are generally small.)

When I try and them overlay these photos with 3-view drawings from various sources, the differences can be quite striking (in an incredibly anal sort of way.)

My goal is to start with the best information I can find, as I know that in the process of creating the individual parts, I am going to make errors, no matter how slight, which will make the end product less than perfect (as indeed the various sub-manufacturers in the original production lines would have faced this same problem.) What I am looking to avoid is to compound the errors of others, where I am taking their less than accurate rendering of various shapes and outlines and compounding those errors with my errors in the process of creating the piece.

To that end, I need to know what the original source looked like. Even working from period photos (which I differentiate from current photos, as most of the existant aircraft may have been restored or altered in some way) is compounding the errors of the original manufacturer in rendering the parts.

So yeah, I'd love to have a set of draftsmen drawings of the original parts, or save that then a good set of photos of original units, or save that then a set of accurate drawings made after the fact. I'm in the process right now, and at some point very soon I am going to say, "close enough for jazz!" and build my beauty.

So thank you all for exercising my brain and helping to keep the Alzheimer monster at bay, for your information and thoughts. I greatly appreciate it!

Paul

[Kutscha]

From the introduction in 'Aircraft Archives - Fighters of WW2' Vol 1

"The books in this series form a representative group of subjects. Each is a typical example of skill and dedication applied by an amateur researcher over countless hours of translating measurements and photographic interpretation into a multi view scale drawing which, in fact, no manufacturer's general drawings could ever provide! For it may come as a surprise, but the reality is that manufacturers' general arrangement drawings have little value in the factories, are rarely accurate in shape or scale and. without exception, illustrate the aeroplane in a stage long since superseded by production variants. It is the sub-assembly, or component detail drawing, which offers priceless data for the researcher to complete the jigsaw puzzle of any aeroplane."

[mmoustaf]

Originally Posted by Kutscha

From the introduction in 'Aircraft Archives - Fighters of WW2' Vol 1

It is the sub-assembly, or component detail drawing, which offers priceless data for the researcher to complete the jigsaw puzzle of any aeroplane."

I would definitely agree with all written above but quoted example in the priceless data terms.

it worth of price, but it necessitate really good engineering skills to complete this puzzle and then rebuild a "new bright world with correct general arrangement in 72nd scale" and sometimes this work takes much more efforts than real benefit would have take place at all.

What am i doing now is generating a new set of drawings using assembly plans, general dimensions and photographs for my book in Russian about 109 of different manufacturers (especially G-6 which I'm pointed on) and I definitely agree this is a hard work and somehow a question of trust.

[Crumpp]

in fact, no manufacturer's general drawings could ever provide!

It must be pointed out that general arrangement drawings are not the topic under discussion.

It is the sub-assembly, or component detail drawing, which offers priceless data for the researcher to complete the jigsaw puzzle of any aeroplane."

It is the accuracy of the sub-assembly or component detail drawings in relation to the production variant.

All the best,

Crumpp

[olefebvre]

Yes indeed, having a set of Emil's rudder drawings under my nose i can say that the rudder construstion is quite a challenge... The rudder profile being absolutly not symmetrical for instance.

[Crumpp]

Hi olefebvre,

That is why we have jigs.
Using them we can produce multiple complex assemblies with compound curves that are exactly the same.

[olefebvre]

Hi Gene,

Out of curiosity do you use some kind of 3D measuring machine to reverse engineer some of parts for which you don't have the exact dimensions (missing factory drawings for instance) ? Or do you rely on more usual and cheaper measuring tools ?

Oli.
Not sure you realised it was me

[Crumpp]

Out of curiosity do you use some kind of 3D measuring machine to reverse engineer some of parts for which you don't have the exact dimensions (missing factory drawings for instance) ? Or do you rely on more usual and cheaper measuring tools ?

Hi Oli!

I figured it was you. No my friend we rely on much simpler tools. Certainly there is error within the tooling but that level of precision is well beyond what can reasonably be expected.

If you build a jig then parts can be produced that fall within very narrow margins. Certainly not six sigma standards but then again 3.4 defects per million opportunities is well beyond most companies capabilities today.

All the best,

Crumpp