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

[chuck540z3]

Looks like a real cockpit to me!  So much work, but so worth it.  Go Jay Go!

 

Cheers,

Chuck

[JayW]

Here is a tough one I need some help with.  Pressurized bottles.  The F4U-1A has three bottles in the cockpit, all at least partly visible, and all on my short list of work to be done.  The oxygen bottle (RH side by the seat), the landing gear "emergency release" CO2 bottle, and the vapor dilution CO2 (or is it nitrogen?) bottle (both underneath the LH side console).  I have enough information to get the sizes and shapes right, but I have no information at all as to their color and any stenciling they would have.  Anyone have anything?     

[Out2gtcha]

Wow. Utterly amazing! I cant believe I missed the update on this one, the scratch work on the side walls is stupendous.

[JayW]

On a completely different subject - Wheels and tires.  I want to turn these parts on my lathe during cold weather, as the lathe motor stays cooler that way.  So I am going to machine them fairly soon.  It has not been easy to determine the exact dimensions of these parts.  The drawings only specify 32 x 8 tires (one could presume 32 inch outer diameter and 8 inch width at the sidewalls, and he/she would be wrong).  Wheels and tires are government-furnished equipment (Goodyear) so no detail dimensions are provided.  So one must do some scaling on any drawings that show the LG.  When I do some scaling on the landing gear installation drawing (VS-10275), I get different dimensions.  Not only that, but I think some liberties had been taken by the drafter - some parts do not appear to be drawn entirely to scale when compared to dimensional callouts on the detail parts.  I include one frame of drawing 10275 for your viewing pleasure:

 

 

Is that cool, or what?  This drawing suggests (by scaling) the tire diameter is about 30.75 inch and width is about 8.75 inch.  Not exactly 32 x 8!  Not only that, but I checked the F6F Hellcat LG installation drawing (these drawings are available at AirCorps Library of course), and got similar dimensions with similar scaling methods.  The F6F and F4U shared the same wheels and tires, FYI.

 

Another drawing, brake installation drawing 10277 reveals the shape of the wheel itself (at least the width and diameter can be gleaned), although in "phantom", or "reference":

 

   

 

Research on other drawings has given me firm dimensions for the bolt circle diameter (7.00 inch), the offset between centerline of strut and centerline of tire (7.50 inch), and distance from axle to lower torque link attach (8.00 inch).  From these dimensions I can scale and get fairly close with wheel dimensions:

 

Wheel outer diameter is about 18.0 inch.  Wheel width is about 8.55 inch.

 

Question for my Corsair experts:  Can any of you verify or correct these dimensions for wheel and tire?    

 

Edited February 16, 2021 by JayW

[brahman104]

I wish I could help with that one Jay, but it looks as though you're doing everything I would. I've found the same issues with a number of B-17 drawings and conflicting dimensions. At the end of the day, if all else fails, the Mk1 eyeball gives a pretty reasonable interpretation in 99.9% of cases!

 

Craig

[JayW]

2 hours ago, brahman104 said:

I wish I could help with that one Jay, but it looks as though you're doing everything I would. I've found the same issues with a number of B-17 drawings and conflicting dimensions.

 

Come to think of it Craig - when I did my Mustang years ago, there was all kinds of discussion about it over on the P-51 SIG website.  Everyone had an opinion.  For teh Mustang though, there was more info floating around the net, and I eventually homed in on it.  Not as much on the Corsair for some reason.

[Oldbaldguy]

I’m not sure I’d rely on called-out tire specs like 32x8, etc to determine the size of your wheels and tires.  I think that’s tire company speak known only to the initiated - it makes sense to a tire guy, but not anyone else.  My Cub sported 8.50 by 6 tires, for example, but I don’t think you could actually measure those dimensions anywhere on the tire if your life depended on it.  Short of visiting an existing Corsair with tape measure in hand, your Mk 1 eyeball may be your best bet.

[TAG]

On 2/1/2021 at 4:04 PM, JayW said:

Here is a tough one I need some help with.  Pressurized bottles.  The F4U-1A has three bottles in the cockpit, all at least partly visible, and all on my short list of work to be done.  The oxygen bottle (RH side by the seat), the landing gear "emergency release" CO2 bottle, and the vapor dilution CO2 (or is it nitrogen?) bottle (both underneath the LH side console).  I have enough information to get the sizes and shapes right, but I have no information at all as to their color and any stenciling they would have.  Anyone have anything?     

 

Dude.

 

Jay.

 

Just...

 

WOW!

 

 

Re: bottle colors, here's a thread @Wolf Buddee started a few years back about that very subject, some good info on there:

Keep up the epic work, CANNOT wait to see the next installments!

 

Cheers,

Thomaz

[JayW]

20 hours ago, TAG said:

Re: bottle colors, here's a thread @Wolf Buddee started a few years back about that very subject, some good info on there:

 

Yes!  I actually found that same thread after I posted about it.  Left me just about as confused!  I went with yellow for the O2 bottle by the way, I dunno - just because.  I am still undecided on the CO2 bottles but am leaning toward gray and black.

 

Thanks for looking in!  

[JayW]

A while back I stated I would be doing some limited cockpit work and then closing it up for a long period while I did the inboard wings.  Well, I am finding there is a whole lot of cockpit work that can be done before I go to the wings.  Here is another cockpit update:

 

The horizontal beam on the Sta 186 bulkhead (that I cut in half) is fragile and easily catches on things like my sleeve or a fumbling finger.  So each side needed some reinforcement.  The LH side was reinforced by the side console (sort of).  The RH side needed something so I took a break from the LH side and did up the O2 bottle and its support stand:

 

 

You can see it somewhat reinforces the beam.  Hard work - almost entirely because it snugs up to the side wall and the side wall on this model is grossly out of scale due to its thick gage.  A layout helped, but I can only approximate the local contour so I have to resort to a bit of trial and error with the bracketry.  The bottle itself is acrylic and turned on the mini-lathe, and is something like 0.2 inch shorter than it should be to clear the aforementioned sidewall.  The hardest part was the straps just due to very small details.  As you can see I chose yellow for the color; some of you would probably have chosen green.  Pressurized bottle colors for WW2 aircraft is an interesting subject with many opinions.... When I get to the RH side, this bottle will be plumbed to the familiar O2 regulator and its long flex hose.

 

And then it was back to the LH side, where I will be for a good while longer.  Gadgets galore!  Next to the seat are two details that need to be there even if largely unseen.  One is a pulley bracket support shelf, and the other is a truss/bracket structure that supports the CO2 bottles and also the hydraulic hand pump.  It is a good example of a poorly designed afterthought of which the Corsair has many examples (IMO).  I provide pictures from the parts catalogue to help describe.

 

First the pulley bracket support shelf (for aileron trim cables, tail wheel lock cable, and wing hinge pin lock cable):

 

 

And the CO2 bottle and hydraulic hand pump support bracket:

 

 

 

And my versions of these details:

 

 

Not perfect by any means.  But once I get the bottles in there and tighten the cables (fishing wire), it should look the part.  It will probably take a flashlight to see them once the cockpit is done and the seat is installed.  That truss/bracket thing was a major PITA I can tell you!  Lots of tweezer work on small parts, and trial & error trimming.

 

Next post you will see the CO2 bottles and their very interesting cradles, and the hydraulic pump.  Take care!

 

  

 

 

Edited February 16, 2021 by JayW

[Maybach_man]

Dont know if this helps....

https://www.adamsaviation.com/files/ww/Catalogues/goodyear.pdf

[JayW]

On 2/11/2021 at 4:49 AM, Maybach_man said:

Dont know if this helps....

https://www.adamsaviation.com/files/ww/Catalogues/goodyear.pdf

 

Thanks for that.   It had critical dimensions for certain tire and wheel sizes, just what the doctor ordered, but not the tire size for the Corsair (or any other vintage warbird).  Thanks.  One thing I did notice - tire diameters and widths vary with air pressure more than I would have imagined.  So I should not be sweating getting it right down to the fraction of an inch.   

[JayW]

I don't like to post erroneous information, so here is a correction:

 

 

So that weird truss/bracket under the LH side console has three (not two) functions:  Mounts for CO2 bottles, the hydraulic hand pump, and also the fuel selector valve.  I had the hand pump going where the fuel valve should be.  in my defense, the drawings defining all this were of very poor quality, so light and underexposed they looked blank. 

 

And here I show the fuel selector valve fabricated (out of the various standard plastic stock), and installed on the bracket:

 

 

 

That valve has six ports where hoses can emanate from (three are on the far side of the valve hidden from view, and you see the other three).  This one will get five hoses, one port has a plug (the middle one seen above with the square peg).  Five hoses for the following:  LH wing tank, RH wing tank, fuselage tank, reserve tank, and the engine.  Three of the five hoses have been added so far.  The other two will come later after the fuselage halves have been joined and attached to the center wing.  Note how those hoses (actually 18 gage wire sheathing 0.08 inch diameter) crowd that pulley bracket.  Far as I can tell that is accurate; I don't think you will ever see a picture showing same on a real aircraft.  These are details that will only be visible if you look hard for them, when this thing gets finished.

 

The above installation was challenging.  The wire sheathing is stiff and doesn't want to bend.  Care had to be taken to not break off a part or ruin the bracket.  Note I have also added the red selector arrow handle and its shaft with a UV joint, interfacing with the selector valve.  

 

One more thing.  The fuel system for the Corsair is a dizzying series of continuing development.  The first version for the early birdcage aircraft had an internal fuselage tank and two internal wing tanks.  The second version (mine) had that plus a centerline jettisonable tank under the belly.  And then D-models had two jettisonable tanks mounted on wing pylons just to the side of the belly jettisonable tank, and deletion of the internal wing tanks, I believe.  Each of these versions had different fuel hoses and lines with different routing.  And it is not easy deciphering the drawings to figure out what the right configuration is to model for my aircraft (a middle run -1A).  I found out just a few days ago that instead of five fuel hoses, there is a sixth which my airplane is supposed to get - for the belly tank.  That sixth hose has a circuitous routing through penetration holes in several belly frames that I have already installed WITHOUT those penetrations (they were not shown on the drawings!).  That was not good news.  So, this airplane is not going to get that sixth hose even though it will have the belly tank hooks.  Honestly, I have to realize that this kind of stuff is never going to see the light of day.  Nobody on earth save myself is going to peer into this deep dark ugly cockpit and notice it lacks that sixth fuel hose.  Get a grip Jay!

 

Next post, the CO2 bottles and hydraulic hand pump will be finished at least.  Then it will be on to the engine quadrant and flap position sector.  At that point I believe the LH side of the cockpit will be as finished as I can get it, and I can start on the equally busy RH side.  Man, what a cockpit....alot of challenges remain.

 

 

 

  

 

 

Edited February 16, 2021 by JayW

[Jim Cox]

Excellent work! Anticipating each post...

[airscale]

crikey! that last pic is indistinguishable from reality Jay, absolutely spectacular

 

Your love and knowledge of your subject just shines through, and the research time alone would be equivalent to a normal model build..

 

..but then that is why I tune in, this is no normal model build

 

Peter