1/18 Scale Blue Box F4U-1A Corsair Modification

[LSP_Kevin]

Exceptional work as always, Jay!

 

Kev

[brahman104]

Definitely finding it hard to articulate exactly how awesome this is Jay! I just can't fathom the complexity that you're pulling off here....

 

I feel like restorers are going to use THIS as a reference!

 

Cheers,

 

Craig

[JayW]

The time has come to start clamping things to the engine mount truss.  Tons of clamps required.  Who can help direct me to a product that will help me?  Or perhaps a method of fabricating clamps?

 

Here are the clamps largely used on the Corsair:

 

 

Scaled to 1/18, most of the clamps I  need are from .020 to .040 inch wide, as thin as possible, and wrapped around various diameters.

 

Chuck used clamps from modelcargarage for his 1/24 Hellcat recently.  I searched that web site - and came up with this:

 

  

 

I wonder if this is it..... They look to be photo-etch, which makes me fear for the very small applications, not so much fear for larger applications, like wrapping around a .125 inch engine mount diameter tube.  

 

Any ideas?

[Shoggz]

Genuinely jaw-dropping stuff.

[Rocat]

Beautiful work!

[chuck540z3]

On 4/14/2022 at 8:39 AM, JayW said:

The time has come to start clamping things to the engine mount truss.  Tons of clamps required.  Who can help direct me to a product that will help me?  Or perhaps a method of fabricating clamps?

 

Here are the clamps largely used on the Corsair:

 

 

Scaled to 1/18, most of the clamps I  need are from .020 to .040 inch wide, as thin as possible, and wrapped around various diameters.

 

Chuck used clamps from modelcargarage for his 1/24 Hellcat recently.  I searched that web site - and came up with this:

 

  

 

I wonder if this is it..... They look to be photo-etch, which makes me fear for the very small applications, not so much fear for larger applications, like wrapping around a .125 inch engine mount diameter tube.  

 

Any ideas?

 

 

Hi Jay,

 

Those look almost identical to the ones I used, but I can't tell by size.  My frets are 28 mm X 13 mm, so if those are as well, they are likely the same thing.

 

Great work as usual,

Chuck

[JayW]

I have officially lost my mojo.  I think it is because my next task must be to add clamps to the engine mount for all the various systems lines and wire bundles.  No fun, but I must do it now.

 

Meanwhile - a reminder of my subject (currently):

 

 

Ignore the "F4U-1D" - that is in error.  I picked this subject a couple years ago.

 

I have taken pride in all my previous 1/18 builds to not have any "anachronisms".   That is to say, to select a subject (so far mine is Jolly Rogers #29, Bu No 55995, line number 1636, pilot Ira Kepford), and not put on that subject a feature that doesn't belong on that subject.  Line number 1636 - remember that for the discussion that follows.  We all know, or should know, that wartime aircraft underwent alot of changes throughout their service runs.  That is certainly true of the F4U.  So how picky should we be....  I know it is possible to go too far and be too picky.  After all, most modelers are not privy to the engineering drawings or parts manuals as I am (subscribing to Aircorps Library).  But alot of it is important, and visible.  So I have recently discovered some dismaying things about my plans for this subject. 

 

One of the most important, in my opinion, is the incorporation of pressurized ignition on the engine, and incorporation of water injection.  These are visible items, easy to pick out (although for the latter only if the accessories compartment is open).   

 

Pressurized ignition - R-2800's with pressurized ignitions have entirely different distributor housings and ignition harnesses as opposed to earlier unpressurized versions.  These items are prominent on the nose of the engine.   My engine has the earlier (unpressurized) version, like this:

 

 

Dana Bell volume 2 states that the pressurized ignition became effective on line number 1551.   85 units BEFORE my subject was manufactured.  Uh oh.  To me, a deal breaker.  I must now select a different subject, with a line number at or before 1551.  Either that or have an obsolete engine in my subject.  No way.

 

Water injection - this was added at line number 1552, 84 units before my subject.  And I had no plans what so ever to add the water injection equipment to the engine accessories compartment.  Too complicated!  So again, I need to change my subject to an earlier one.  But, the pressurized ignition problem above has made this a moot point.

 

Also dismaying to me is cowl flaps.  All early Corsairs had cowl flaps that extend all 360 degrees around the cowl.  This led to problems in service where oil leakage (or other fluid leakage), when cowl flaps were open in flight or take off, could spew out of the gap and deposit itself onto the windshield.  This was eventually fixed in production with a "dead flap"  fairing which replaced the top three cowl flaps.  I provide a picture from the parts manual showing both the "before" and "after" shoulder configurations under the cowl flaps:

 

 

You can see the fixed fairing which replaces three cowl flaps on top of the aircraft fuselage.  And I went through the trouble of Rhino modelling it and having it 3D printed:

 

 

That pic doesn't include the cowl flaps themselves but hopefully you get the message.  But the "dead flap" it didn't come on line until line number 2325, fully 689 line units AFTER my subject!  Whaaa?  How could I make that mistake?   Here's how - I wasn't paying attention.  I have seen many pictures of early F4U's - birdcage versions or early -1A's - with the top three cowl flaps shut.  I assumed wrongly that the later "dead flap" was installed.  No, instead, a field modification was incorporated to bolt a fixed plate over those flaps to keep them closed.  I think the mod was fairly simple.  It was not incorporated on every unit in the field, but many including my subject #29.  So what am I gonna do?  I am going to abandon my beautiful 3D printed dead flap part, and Rhino model another curved shoulder for the top of the diaphragm, which accepts the full array of cowl flaps.  I am undecided whether or not to have a simple plate over the top three flaps - I make that decision later.  I am inclined to.... and I am accepting suggestions.

 

There is more.    The bomb window - I thought it was discontinued on the first F4U-1A (line number 0950).  Well it wasn't.   It stayed with the configuration, according to Dana Bell, until line number 2531.  895 line units after my subject, and almost to the point where the -1D model was introduced.  Really???  So I decided to double check Dana and ran into troubles.  First, the parts manual provided in Aircorps Library is a 1945 edition, and doesn't even show a bomb window at all!  What an omission - it shows all manner of previous configurations back to the bird cage versions, all over the airplane, but not the bombing window?  I checked the drawings.  Sure enough, the drawing where the bomb window is called out (VS-10250 - "Fuselage Assembly Complete"), in one of its late revisions and not earlier revisions, specifies the replacement aluminum lower panel for the bomb window and it incorporation point.  But alas - the note that defines its incorporation point is too fuzzy to read!!!  I can however tell when that note was added to the drawing by the revision block descriptions, and it appears that it was added in late 1943, whereas the -1A version of the Corsair was introduced in early 1943.  This tell me many -1A's retained the bombing window.  But I am unable to verify just which line number the aluminum panel came on line. 

 

Of course, if you follow this build, you already know I skinned over the bombing window.  And it's going to stay that way.  So, I am going to pick a subject before line number 1551 as described above, and that subject probably but not certainly had a bomb window.  And I must live with the anachronism.  Oh well....I feel stupid.

 

I cannot tell you how many times I chose a configuration to build based on line number 1636 (the Ira Kepford aircraft).  This is especially true in the cockpit.  And now I am going to abandon this subject and go with an earlier aircraft on or before line number 1551.  I don't even recall which configurations I modeled will become invalid.  But it's just as well - the #29 Kepford aircraft is so popular that I feel like doing something different anyway.   I would still like to do a subject from fighting 17 (Jolly Rogers), and there are many which would fit the bill.  I'll decide before too long - I  have more to build and I would like to settle on a new line number so I can continue trying to put the right stuff in there. 

 

A post on the accessories compartment will come soon.  Take care.     

 

 

 

 

 

 

Edited April 20, 2022 by JayW

[brahman104]

Sucks to hear that Jay! I know pretty much everyone reading this would say "don't worry about it, and you're the only one who's going to know," but I know the extreme levels of dedication you've gone to with this build to get everything as it should. 

 

Having said that, the realities of war might afford you some leeway. Most of these aircraft probably had an engine change at some point in their lives and an earlier one may well have still been in the supply chain at the time. Same could probably be said for some of the other discrepancies you've found. I know a lot of research goes into the documents you're getting your information from, but there's even still bits and pieces that happened to these frames that weren't especially well documented.

 

Take the B-17 or B-24 for example, there's so many modifications that went on not only during the production runs, but also intermediate depots and then sometimes by individual crews to make up for deficiencies in the field, and perhaps even several times over the course of their service.

 

Realistically (and I know that you know this  ), unless you have the actual aircraft in front of you and you are modelling it as it stood that particular day, can you really be certain that what you've depicted couldn't actually be correct at some point? Certainly not trying to downplay your revelations here Jay, but you've got one hell of a model and it represents an extraordinary amount of talent in it, who could stand before you and argue any different?

 

Just my thoughts  

 

Craig

[Oldbaldguy]

Sounds like you need to stick a list of Corsair production line numbers on the wall and chunk darts at it til you hit one you can live with.  I promise that whichever one you build, it did not remain in 100% Vought production drawing configuration for very long.   Very few airplanes do.  Back when the Vigilante was brand new, my dad would come home frustrated as a hell because they’d have to rewire major systems on brand new airplanes because they didn’t work as advertised once they were delivered to the squadron.  Even staid and reliable Cessna was said to have built new 172s knowing they had airworthiness directives that went into effect the instant they were pushed out the door.  It was harder and more costly to introduce changes to the production line than it was to put off fixing whatever needed tweaking until after delivery.  So, in reality, even though all these airplanes were built to spec, production drawings often are more of a general guide than the law of the land once the airplane enters service.  Who’s to say that even though Corsair #1512 (if you were to build that one)rolled out of the factory with a flobzit reamer installed per working drawing No. 17B, Sheet 42, that a couple of months later it was not sporting a grunch converter instead just because a maintenance chief decided it worked better and he had one lying around.  Whatever.  We won’t know any better.  Besides, it’ll be grand.

[JayW]

2 hours ago, Oldbaldguy said:

Sounds like you need to stick a list of Corsair production line numbers on the wall and chunk darts at it til you hit one you can live with.....

 

Part of the problem is that quite a few Vought drawings undergo a revision without the previous config retained on the drawing, like a different sheet number, or a pull-out view, and a dash number change.  No, the new revision just blots out the old, even though the old exists on aircraft in the field!!  Not cool!   And, with civilian aircraft, not per FAA rules.  Complicates things.  Anyway - I am making mountains out of mole hills.   Ill get there by hook or by crook.  Thanks for the comment.

[Bobs Buckles]

Awesome progress!

 

 

Bob 

[dodgem37]

OOF!

 

1/16

 

 

 

Found here: https://www.modelmotorcars.com/instructions-installing-hose-clamps/ if you're interested.

 

Sincerely,

Mark

[airscale]

Well Jay, I feel your pain - I have been there many times when I made something from drawings and then found my subject was different - it is a disheartening feeling, but never irretrievable..

 

We all know your compromise-o-meter is set at a flat zero - anyone who builds an 18 cylinder radial, cylinder fin by cylinder fin and then adds all the anciliaries for 'fun' approaches their subject with the discipline of a nuclear scientist, so there is no situation where you can 'live with' something you know is not right, I 100% understand that

 

However, in this case, I think there is a bright side. If I read you right, the only actual rework is the cooling flaps atop the cowl and much as it is painful to write off work, really this is the only casualty. The reason I think it's a good thing is that the rest is fixed by choosing another subject & here I have never favoured doing super well known subjects, they are a bit 'Disney' for me. While they obviously have a place in the model world, I think in our efforts to recreate the machines from our past, I would far rather look at a more esoteric, less well known, if not unknown subject.

 

Hopefully you can refocus, and to be honest when my mojo gives, I just move onto another part of the airfame and come back to what was getting me down later. Ultimately everything needs building so the order can be played with a bit

 

It doesn't help you, that I see it as a hidden bonus, but at least you know there are other perspectives on the problem

 

All the best

Peter

[JayW]

2 hours ago, dodgem37 said:

OOF!

OOF is right!  What an incredible store that is.  Those kind of radiator hose clamps, however, do not show up on the details I am building for the Corsair.  Now the Mustang - different story!  

[JayW]

2 hours ago, airscale said:

However, in this case, I think there is a bright side. If I read you right, the only actual rework is the cooling flaps atop the cowl and much as it is painful to write off work, really this is the only casualty. The reason I think it's a good thing is that the rest is fixed by choosing another subject & here I have never favoured doing super well known subjects, they are a bit 'Disney' for me. While they obviously have a place in the model world, I think in our efforts to recreate the machines from our past, I would far rather look at a more esoteric, less well known, if not unknown subject.

 

Thanks Peter for the words of encouragement.  Yes it helps.  Still galls me though to make a mistakes like that....

 

Curiouser and curiouser, I have noticed that there was a block of aircraft that got the bombing window frame, with the glass replaced by a sheet of .064 aluminum.  And then later on the entire window frame was replaced by a new integrally stiffened panel assembly (the one created when I skinned the belly a month ago).  This would have been entirely retrofittable, I would have to assume.  Although it is still a mystery where the production cutoff was for the original bombing window installation, this discovery makes me feel better about my subject not having the window.