1/24 Airfix F6F-5 Hellcat "Kicked Up A Notch": New eBook Now Available!

[CraigH]

6 hours ago, chuck540z3 said:

 

Sorry Craig!  As for the decal, you are in good company, because every single build of this kit seems to have it that way, thanks to the incorrect instructions.  As mentioned, I've looked at hundreds of pics and not one of them has a stencil of any kind next to the antenna wire and considering how large and clear the lettering is, this is a major error in my mind.  If I might make a suggestion, getting rid of the decal is more important than finding a new one, because the pitot stencil is very small and on many aircraft almost invisible (if not invisible).

 

Cheers,

Chuck

That's my thought. I'm have a printed version of the notice from a reference book so I've scanned it, photoshopped it and I'm going to see if I can get a good enought print resolution to print one on decal paper. Not hopeful though

[CraigH]

46 minutes ago, John Stambaugh said:

Here again is a fine example of individuals, dedicated to their craft who make the extra effort to "get it right ". 

 I must admit that I will eagerly take  your expertise for my benefit. 

 Both Craig and Chuck have laid down a detailed roadmap that makes this build less daunting for me.

 Gentlemen, I thank you. 

You are more than welcome John. Advice will be $10 a post when you start 

[John Stambaugh]

8 minutes ago, CraigH said:

You are more than welcome John. Advice will be $10 a post when you start 

I'll be in touch

[chuck540z3]

March 25/22

 

 

 

 

On to finishing the landing gear, which is mostly painting.  I am using the Aerocraft Brass Landing Gear as well as the Barracuda Diamond Tread Tires/wheels (BR24412) sets, which I prepped on Page 16 of this build thread for those who might be interested.  The Aerocraft set comes with new resin gear doors, because the brass gear has a fairly well-defined brake line that gets in the way of the kit door attachments.  The doors also have stiffening brackets molded on the inside, that are 2 L-shaped bars that are side by side on the real deal.  Unfortunately, there is nothing to attach the doors onto the gear legs, other than a couple of strips and the brackets are not very well cast.  After fiddling with these doors on the brass gear a bit, I came up with a better solution, which is to add stiffening brackets to the kit doors, trim off the tabs on bottom 2 of the U-shaped attachments at the rear, and widen all of the attachments to accommodate the slightly wider brass gear.  I also filled the lower pin mark hole since it can be seen if you look hard (bottom of “Widen arrow”), while I left the upper 2 holes alone because they are completely hidden by the gear leg.

 

 

 

 

The outside detail of the kit door is also a bit crisper than the resin versions.

 

 

 

 

Here is why the bottom 2 U-shaped tabs get in the way of the brake line, while the top tab is fine if it is widened and the top of the door is sanded back a bit in order to fit.  At this stage I have painted the brass with Mr. Metal Primer-R, followed by Mr. Surfacer 1200, and gloss black and Alclad Chrome on the oleo.  Although it can cut back the shine of the chrome, I then sprayed a coat of Tamiya X-22 to seal the chrome in, otherwise the Alclad would lift when it was masked off.  So, although it doesn’t look like much, that oleo strut has 5 separate coats of paint!

 

 

 

 

The landing gear, tires and wheels were then painted, followed by the same weathering washes I applied to the fuselage to match the underside.  After the dry-fitting work I did earlier, everything fits strongly without the need for glue, although I will likely add a bit here and there to make sure that nothing moves later.  The first thing that comes to mind is just how big this model is, because the landing gear really makes it stand high.

 

 

 

 

Sometimes photography doesn’t replicate what my eye can see, because the bright lights really picked up the aluminum-colored wash, which looks way too bright and unrealistic.  The excellent detail of the Barracuda resin really comes to life, however, despite these pics.  All I can say is, “trust me”, they look really good and realistic for a weathered aircraft in person.

 

 

 

 

Another angle to show the deep detail within the wheel, despite the bright reflections.

 

 

 

 

The oleos came out looking really good without lifting and BTW, that inner oval plate is different on both wheels (L & R), and should be roughly perpendicular to the gear leg.  This should have been mentioned in the Barracuda instructions, but thankfully, I noticed the differences and checked a few references.

 

 

 

 

Unfortunately due to the tire and gear door, the oleo will be mostly hidden from both sides.

 

 

 

 

The other side, which gives a better pic of the inner oval plate on the wheel.  The brake line was hand painted in dark grey for a bit of contrast.  Now you see the oleo…

 

 

 

 

Now you don’t, unless you peek inside from the front.  Note that the gear doors dry fit nicely to the legs, which will make gluing them later easy and secure.

 

 

 

 

The rear wheel assembly is also hard to photograph because it’s so dark against a dark background, but it fits really well now, thanks to some modifications I made on Page 16 to bend the brass and add a small axle to the kit wheel.

 

 

 

 

Much of the bottom of this assembly will also be covered by a gear door, but you can still see some good detail from the side.

 

 

 

With most of the landing gear hassles out of the way, I can now finally attach the engine, which is a big relief when I do.  I still have a lot of things I want to do to the engine like adding a few more parts, weathering and paint touch-ups, and with it securely off the ground, I don’t have to handle the sucker any more with my hands, which always seems to remove a bit more paint.  Hopefully I don’t drop it on the floor again like I did last time I attached it!

 

 

I’m off for a few days so no update for at least a week or more, and thank you for your continued interest in this build.

 

 

Cheers,

Chuck

Edited March 25, 2022 by chuck540z3

[SwissFighters]

Great work Chuck!

[shark64]

this is always a treat to follow. You are one talented modeler.

[rafju]

And the pictures are outstanding!!!

[dodgem37]

Great show, Chuck.

 

Sincerely,

Mark

[JayW]

Oh man what a professional job on the all important landing gear!  It is exquisitely detailed, and clean looking.  

 

Did I gather that the wheels are not yet glued on?  I ask because I would recommend the tire flat be visited.  On my Corsair build (BTW, Corsairs and Hellcats shared the identical wheel/tires), there was lots of sometimes passionate discussion on how much flat these tires sported. 

 

Here is my math (forgive me if it sounds like an elementary algebra class): 

 

According to the Erection and Maintenance manual, recommended main tire inflation values are as follows - 131 psi for landing weight of 14K lbs, 99 psi for landing weight of 10K lbs.  Roughly linear variation for weights in between.  Those are carrier deck values; the shore based values are about 15% lower.  A max take-off gross weight F6F is a bit over 15K lbs.   Empty weight is about 9.3K lbs.  Let us suppose your aircraft has a weight of 13K lbs, which is somewhere in between.  Your oleo extension suggests the aircraft is not fully loaded.  Let us also suppose it is at max recommended tire pressure (131 psi).

 

Let's assume that about 90% of the weight of a Hellcat is on the main wheels (10% on the tail wheel).  That means each main tire sees .9 x 13K / 2 = 5850 lbs of weight.  

 

To calculate tire flat area in square inches, divide weight by tire pressure.  5850/131 = 44.6 sq in.  This value ignores any stiffness of tire sidewalls, which would have some ability to support some small amount of weight even with zero tire pressure.  But that would be very small (a weight of 200 lbs would probably completely flatten an uninflated tire).   Compared to 5850 lbs, that is negligible.

 

To take that down to 1/24 scale, that tire flat area value must be reduced by 24 squared.  44.6/24/24 = .077 sq in. 

 

If the tire flat were a circle, area = pi (radius squared).  Or, do a little algebra and the radius of the circle = sq root (area/pi).   For the 1/24 scale Hellcat the radius works out to be .156 inch.  (math check:  area = pi x radius squared = 3.1416 x .156 x .156 = .076 sq in.  Close enough).  A radius of .156 inch = a diameter of .312 inch. 

 

So, if your tire flat were circular, you would expect it to be .312 inch diameter.   However, the tire flat is more oval than circular.  So the major axis will be larger than the minor axis, but the .077 sq in area must be the same whatever the shape of the oval.  BTW, the area of an ellipse (oval) = pi x semi-major axis x semi-minor axis, where the "semi" means half the length of the axis (like a radius is to a diameter).  

 

Measure the flat you have currently and see how close it comes to .077 sq in, or about .31 inch by .31 inch.  I suspect it is far smaller.  An oval flat of say  .38 inch by .28 inch would get you in the ballpark. 

 

Another way to look at it is to observe the tire tread.  There is no need for a tire tread to be as wide as it is on that tire, if it never contacts the ground.  So it would seem logical to assume the tire flat should encompass, or nearly encompass, the width of the tread on the bottom of the tire. 

 

I know many modelers create unbelievable models, and refuse to put any flats at all on the tires.  I am not sure why, but they must have their reasons.  For me, I want my models to depict a real aircraft sitting on the ground.  Which means on planet earth with our gravity, the tires have to have a flat (and a bulge). 

 

Carrier based aircraft have really high tire inflations.  Pictures can show tires with very little side bulge.  That issue was part of the discussion on my build.  So, if one were to simply sand off a flat and ignore any bulge, one could be forgiven.   But, if a bulge were desired, then if one measured the length of a cross-section of the outside surface of an inflated tire (no bulge), from rim edge to rim edge (that would be roughly a semi-circle), then that length value should be maintained on a cross-section through the bulged portion of a tire.    The shape of the cross section would change obviously, with sidewalls pooched out some, and bottom flat, but the length of the cross-section should remain the same. 

Edited March 25, 2022 by JayW

[chuck540z3]

8 hours ago, JayW said:

Oh man what a professional job on the all important landing gear!  It is exquisitely detailed, and clean looking.  

 

Did I gather that the wheels are not yet glued on?  I ask because I would recommend the tire flat be visited.  On my Corsair build (BTW, Corsairs and Hellcats shared the identical wheel/tires), there was lots of sometimes passionate discussion on how much flat these tires sported. 

 

Here is my math (forgive me if it sounds like an elementary algebra class): 

 

According to the Erection and Maintenance manual, recommended main tire inflation values are as follows - 131 psi for landing weight of 14K lbs, 99 psi for landing weight of 10K lbs.  Roughly linear variation for weights in between.  Those are carrier deck values; the shore based values are about 15% lower.  A max take-off gross weight F6F is a bit over 15K lbs.   Empty weight is about 9.3K lbs.  Let us suppose your aircraft has a weight of 13K lbs, which is somewhere in between.  Your oleo extension suggests the aircraft is not fully loaded.  Let us also suppose it is at max recommended tire pressure (131 psi).

 

Let's assume that about 90% of the weight of a Hellcat is on the main wheels (10% on the tail wheel).  That means each main tire sees .9 x 13K / 2 = 5850 lbs of weight.  

 

To calculate tire flat area in square inches, divide weight by tire pressure.  5850/131 = 44.6 sq in.  This value ignores any stiffness of tire sidewalls, which would have some ability to support some small amount of weight even with zero tire pressure.  But that would be very small (a weight of 200 lbs would probably completely flatten an uninflated tire).   Compared to 5850 lbs, that is negligible.

 

To take that down to 1/24 scale, that tire flat area value must be reduced by 24 squared.  44.6/24/24 = .077 sq in. 

 

If the tire flat were a circle, area = pi (radius squared).  Or, do a little algebra and the radius of the circle = sq root (area/pi).   For the 1/24 scale Hellcat the radius works out to be .156 inch.  (math check:  area = pi x radius squared = 3.1416 x .156 x .156 = .076 sq in.  Close enough).  A radius of .156 inch = a diameter of .312 inch. 

 

So, if your tire flat were circular, you would expect it to be .312 inch diameter.   However, the tire flat is more oval than circular.  So the major axis will be larger than the minor axis, but the .077 sq in area must be the same whatever the shape of the oval.  BTW, the area of an ellipse (oval) = pi x semi-major axis x semi-minor axis, where the "semi" means half the length of the axis (like a radius is to a diameter).  

 

Measure the flat you have currently and see how close it comes to .077 sq in, or about .31 inch by .31 inch.  I suspect it is far smaller.  An oval flat of say  .38 inch by .28 inch would get you in the ballpark. 

 

Another way to look at it is to observe the tire tread.  There is no need for a tire tread to be as wide as it is on that tire, if it never contacts the ground.  So it would seem logical to assume the tire flat should encompass, or nearly encompass, the width of the tread on the bottom of the tire. 

 

I know many modelers create unbelievable models, and refuse to put any flats at all on the tires.  I am not sure why, but they must have their reasons.  For me, I want my models to depict a real aircraft sitting on the ground.  Which means on planet earth with our gravity, the tires have to have a flat (and a bulge). 

 

Carrier based aircraft have really high tire inflations.  Pictures can show tires with very little side bulge.  That issue was part of the discussion on my build.  So, if one were to simply sand off a flat and ignore any bulge, one could be forgiven.   But, if a bulge were desired, then if one measured the length of a cross-section of the outside surface of an inflated tire (no bulge), from rim edge to rim edge (that would be roughly a semi-circle), then that length value should be maintained on a cross-section through the bulged portion of a tire.    The shape of the cross section would change obviously, with sidewalls pooched out some, and bottom flat, but the length of the cross-section should remain the same. 

 

Jay,

 

I take it you want me to make the flat spot bigger?  As you can see on this pic, there is one there already and based upon being a carrier aircraft, I assumed that was enough.  Making it bigger is no big deal, so maybe you can find me something that looks to be just about right. 

 

 

 

Thank you sir,

Chuck

[JayW]

2 hours ago, chuck540z3 said:

Making it bigger is no big deal, so maybe you can find me something that looks to be just about right. 

 if you put the main gear tires on a flat piece of sand paper and began moving it about, you'd gradually increase the flat(s).  I stated that .38 inch by .28 inch would be in the ball park.  But that is just one ellipse.  I don't know what shape you would come up with.  But, if it were circular (it won't be), the flat would be .31 inch by .31 inch.  .40 inch by .25 inch would get you there as well.  That should give you an idea.  What are the dimensions of the flat you now have?

[levier]

Chuck...fabulous!   Jay... that's some serious tire analysis!  All great stuff guys.

[JayW]

Tire flat - Here is another way to do it.  I found this on the F6F-3 General Arrangement drawing "SP1277":

 

 

The F6F-5 should be just about the same.  Note the static load rolling radius of 13 5/8 inch.  This on a 32 x 8 tire.  Careful though - if you scale the tire diameter on that drawing, you get just over 31 inches.  32 x 8, I have found, doesn't necessarily mean exactly 32 x 8 in the world of tires.  Go figure.  I got about the same value (approx 31 inches) on the equivalent drawing for the Corsair (they have the same wheels and tires).  Also, "static load" means full gross weight.  The rolling radius is going to be different (larger) for an aircraft that is less than full gross weight.

 

But take that rolling radius of 13 5/8 inch for a moment.  A tire of 31 inches diameter has a true radius of half that - 15.5 inches.  That means the rolling radius is 88% of the true radius (13.625/15.5 = .88).  If anyone is uncomfortable with that, use 90%.  Now, what does that mean for a diameter measurement?  True diameter, we already determined, is 31 inches.  Diameter at the flat is going to be rolling radius plus true radius = 13.625 + 15.5 = 29.125 inches.  As a percentage then, that is 29.125/31 = .94 = 94%.  And again, if anyone is uncomfortable with that, use 95% or 96%.   

 

An easy way to measure tire flat on a model tire is to get some calipers and measure its true diameter (not radius) away from the flat, and then measure the diameter at the flat.  And compare.  Sand down that flat until you get about 95% or 96% of the true diameter.  This is going to get you just about spot on, for a nearly full gross weight aircraft with tire pressure of 131 psi. 

 

But wait!!  Look at the gear orientation of an F6F:

 

         

 

They tilt inward.  So measuring that flat is going to get a bit messy.  I think you can still use calipers, and still use the same method as I described.  But measure the diameter at the flat perpendicular to the flat, not the axle.  The error will be very slight, and can be ignored.

 

The tail wheel tire ought to have a flat too.  I believe that 95% diameter value ought to be good enough for that tire also. 

 

At this point, I am going to shut up about tire flat.  This is not my model and I have no interest in twisting the arm of the guy who owns it!  Chuck - you do what you want to do, and I think we all approve.  It's a fabulous effort.   

Edited March 26, 2022 by JayW

[zaxos345]

Awesome!!!!!!! 

 

John

[chuck540z3]

Mar 30/22

 

 

I am very glad to report that the engine is finally permanently attached to the fuselage and there were no major mishaps!  I did mange to get some CA glue dripped on one fuselage side (grrrrr), but the clean-up was fairly quick and uneventful.  For this kit, that is a HUGE step to get behind you, because the model is huge, the 4 engine mounts don’t slide into place without a fight and when I added 3 oil lines, it made a tricky procedure that much more difficult.  Anyway, it’s done.

 

 

Here's a pic of generally what I’m shooting for in terms of displaying an engine under maintenance.

 

 

 

 

And my preliminary results.  I really toned down the bright orange color of the spark plug wires with pastels.

 

 

 

 

The “stressed skin” look on the wings looks quite cool from this angle.

 

 

 

 

 

 

This area has been weathered, but obviously not enough yet.

 

 

 

 

This lower duct in Step 218 is made up of 4 different parts, which accept a big lower cowling panel (M24) in Step 246.  There are 2 holes to accept this cowling, which I filled in once I realized that I don’t want the cowling at all.

 

 

 

 

I was going to make some oil line connecting tubes like I did before, but ultimately decided to just attach the oil cooling lines to the firewall as is, but they are still in the “correct” order.  I still have lots to do, like add more linkage and line detail to the upper portion of the engine, so wasting my time on the bottom that will rarely be seen didn’t seem worth the additional hassle.

 

 

 

 

I am going to be adding the front cowling part of course, as well as the rear top cowling panel, Part M8.  Checking the pic of the real deal above and other engine references, the recess for the cowling panels is very shallow, and there is a lot of big Dzus fastener holes, so I added strips of styrene and drilled some holes, much like I did on the fuselage and wings already, as you can see above.

 

 

 

 

Another angle to show that the cowling styrene needs to be quite thick at about 0.75 mm, while the fastener holes in the kit crossbeams were either widened or added to match the other holes.

 

 

 

 

The 2 parts dry fit, along with the top cross beam to give an idea of what this bird will look like when finished.

 

 

 

 

Things will snug into place a lot tighter when I apply glue.  Note that there is still a recess on the cowling parts, after the addition of the styrene strips, which looks a lot more realistic now.

 

 

 

 

Like I always say near the end of a build, “I’m running out of parts!”.  I have the canopy, fuel tank, 2 bomb pylons and lots of tiny bits to keep me busy over the next couple of weeks, and then I should finally be done.  Good thing too, because spring has started to arrive to these parts, when my modeling mojo comes to a halt until the snow flies once again.

 

 

Cheers,

Chuck

Edited March 30, 2022 by chuck540z3