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USA Build: A4D-1 (A-4A) Skyhawk, circa 1956, Southern California

An early Scooter in service with the US Navy Reserves at NAS Los Alamitos

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Phil Cooke03/03/2016 20:06:56
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2070 forum posts
1428 photos

Hiya John, great to see you on here with your own A-4 build thread! thumbs up

Is the day-glo A-4A your chosen subject? It looks great in those colours you wont be losing that one! It will be good to see a UK PSS design being put through its paces at one of the ISS events I look forward to that!

J.H. Rood03/03/2016 20:41:57
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165 forum posts
201 photos

Yeah, Phil! Really I am torn between that bird and that foxy astrophysicist CHARLIE's imaginary Aggressor A-4E out on the flightline at NAS Miramar. My first thought is to keep it simple and follow the build plan for an A-4E or A-4F; I absolutely LOVE the Aggressor colour schemes, and their overall clean lines.

But as a youngster in the 1960s I grew up seeing sometimes the bright red & white colors on jets out in the Mojave and Inyokern deserts --- and nowadays at age 61 (almost) I can DEFINITELY benefit from a bright dayglo scheme.

Here is that same particular aircraft (Bu.139934) with a different unit a bit later, circa 1961-63... some hi-viz panels are there, but they are hard to see clearly in the photo:

139934 elsewhere.jpg

And below now again is my first attempt at an A4D / A-4A nose profile fitted to your 1/12th scale design. Mainly it is just shorter, a higher C/L, and the air intake is unswept and a tad further aft. Everything else looks roughly the same, and the A4D-1 had no refueling probe. As always, my main focus is to get the pilot relief tube operating properly.

A4D-1 and -2 and A-4A nose profile.jpeg

Last but most importantly, if all goes to plan, the Mark I Eyeball and the K.I.S.S. principle will be in heavy rotation throughout this little project.

J.H. Rood03/03/2016 20:44:54
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165 forum posts
201 photos

"Call-sign Charlie, Lady, git outa the way!

You're blocking our view of Jester's Top Gun Tinker Toy!"  love

charlie-top-gun.jpg

 

Edited By John_Rood on 03/03/2016 20:51:07

Andy Meade04/03/2016 12:24:43
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2310 forum posts
598 photos

That looks like a great nose profile John - I think it's great that you're going to the trouble to model this extra variant. Will you / can you share a PDF of the changes once complete, so that others could follow?

Git 'er done!

J.H. Rood16/03/2016 16:46:48
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165 forum posts
201 photos
Posted by Andy Meade on 04/03/2016 12:24:43:

...Will you / can you share a PDF of the changes once complete, so that others could follow?

Andy:  YES -- I will do!

Edited By John_Rood on 16/03/2016 16:50:16

J.H. Rood16/03/2016 17:24:00
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165 forum posts
201 photos

Before.jpeg

Humiliatingly, it's been literally YEARS since I've had a workshop up and running, and so this project is a major reentry for me. My first real task has been to reestablish a workspace. Neglect is COSTLY! This has been a REAL battle, but I am now seeing light at the end of the tunnel...

After.jpeg

My building board is a flat, heavy piece of 3/4" hardwood with a pin-friendly flip-side of Masonite sheet attached to the board with Gorilla Glue. Reference lines are helpful for me as I'm a nut about geometry and so forth.

Bare Board.jpg

I'm building from Traplet's laser-cut kit and it incorporates the minor fine-tuning bits discussed thus far on the Mass Build thread.

A-4 Candy Store Opening.jpeg

Helpful --and totally unlike my natural "chaos unravelling" project mismanagement style -- the cool list of other needed stock items!

Stuff to get.jpeg

And here's a good bit of my10+ year old stash of medium soft through medium-hard balsa, spruce, and ply. I'm dumb and unwise, but over the intervening years I actually WAS wise enuff to keep this stash well-ensconced under the bed and away from high heat, cold, humidity extremes.

My balsa stash.jpeg

And lastly here's Clancy The Douglas Tech Rep --- with The Supreme Allied Commander (a drunk feral frog) listing at times overhead with a watchful, wandering eye or two...

Douglas Tech Rep in his C-17 Cargo Bay, with the Supreme Allied Commander overhead and tipsy.jpeg

J.H. Rood16/03/2016 17:28:03
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165 forum posts
201 photos

And yes, that cat up there is inside his exact-scale mockup of a 1/15th scale C-17 transport's cargo bay. Some crazed gent in the PSSA UK has one underway, and my cat has been enlisted as a stress-tester.

J.H. Rood16/03/2016 18:24:15
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165 forum posts
201 photos

Titebond II Gone Bad, and its Partners in Aeromodelling Crime:

image.jpeg

I'm trying SUPER-PHATIC for the first time, on the advice of friends. I hear nothing but GOOD things about the stuff. For USA modelers: http://www.horizonhobby.com/super-phatic%21-dlmad21

image.jpeg

I bought these four from Horizon Hobby and service was VERY fast from Illinois to here in Boston.

image.jpeg

They get special air treatment, these Mass Build participants...

image.jpg

J.H. Rood18/03/2016 20:56:38
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165 forum posts
201 photos

The shorter nose profile of the A4D-1 is penciled-in...

nose profile penciled in.jpg

...and happily the new nose profile will allow the battery box design to go in pretty much as-is...

battery box will just fit.jpg

It makes it, just!

J.H. Rood18/03/2016 23:20:43
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165 forum posts
201 photos

90 degrees.jpg

Heavy 90 degree angle stock to keep things more or less right.

box.jpg

boxdone.jpg

J.H. Rood19/03/2016 00:48:54
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165 forum posts
201 photos

f3 and f6.jpg

Stiffening fuselage structure for wing attach fittings: Laminating balsa with ply, and epoxying-in the lock washer for the wing TE attach point.

f3 and f6done.jpg

J.H. Rood19/03/2016 02:00:51
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165 forum posts
201 photos

OOPS -- I didn't think to mark the lines for F2 and F3 ahead of time... so I had to back into it... AND IT SHOWZ

f2 and f3 box lines.jpg

Because of this tardiness on my part, it proved to be a bit of a hassle to get these lines correct; in fact, from Phil's build thread I see that, to some degree, the fuselage alignment DEPENDS on them to be true. The lines on the sides are intended to slope a bit, as the box is at an angle to the fuselage reference line -- but the lines on top and bottom must be at 90 degrees. And hey yes my lines kinda LOOK a mess -- but I will be careful as this fuselage build proceeds because we really MUST have things straight and true.

f2 and f3 box lines 2.jpg

J.H. Rood19/03/2016 03:48:29
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165 forum posts
201 photos

Dry fitting the avionics box to former F2 and the balsa/ply F3. The balsa base is 1/8" medium-hard that I found in my stash. Lying down up front is former F1, which will be modified to accommodate the A4D's shorter nose profile. The box, too may need to be shortened a bit -- we'll see as things come together.

dry fit.jpg

On the plans I've now shaded in a preliminary side profile for the A4D's shorter nose, including a centerline (C/L) that runs below but parallel to the existing datum line.

a4d shading.jpg

Edited By John_Rood on 19/03/2016 04:08:37

J.H. Rood19/03/2016 17:56:06
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165 forum posts
201 photos

A4D Nose Profile: Now drawing in a TOP VIEW.

I don't know why the photo is flipped sideways! Some kind of forum website software quirk?

No matter -- see that line marked "DOUGLAS REF LINE"? I incorporated it here because, to my eye, that appears to be the place -- a structural firewall, if you will -- where, forward of there, Douglas designers made future modifications to the nose profile. So I can use it as a reference point for "backdating" Phil's A-4E plan profiles to the earlier A4D configuration.

a4d nose development.jpg

J.H. Rood19/03/2016 18:18:13
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165 forum posts
201 photos

And so here is a top view, with the nose shape shaded in... and the dry-fit of the radio box and formers F2 and F3.

All this fuss helps me see where I will in fact need to crop the nose end of the radio box -- in order to achieve the proper A4D nose profile AND build in the structural strength needed there.  Phil and I were writing about this earlier today;  it looks like it needs some trimming in order to get sandable blocks etc for a proper nose taper.

top.jpg

Edited By John_Rood on 19/03/2016 18:43:56

J.H. Rood19/03/2016 18:53:13
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165 forum posts
201 photos

The Douglas Tech Rep has some concerns, too...

douglas tech rep nose check.jpg

Phil Cooke19/03/2016 19:48:59
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2070 forum posts
1428 photos

Good job John, the plan view profiles you've shaded look spot on, don't worry about shortening the battery box and nose by an inch or so, the prototype came out nose heavy with the battery as far forward as it would go on the plan as drawn, so you should still be about on the money for balance without the need for ballast.

Its pleasing to see the shorter nose variant being modelled as well as the longer nosed 2-seater. Great stuff!

Don't get any PVA on the cat wink

J.H. Rood19/03/2016 21:40:45
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165 forum posts
201 photos

All GREAT to hear, thanks, Sir!

Now here's just three quick things: 1.5" removed from the radio box, centerlines added to the box, and laminating sheets of 1/16th" x 4" medium balsa for the 1/4" sheet fuselage floor, here with the help of Super-Phatic and a heavy book of of proper British excellence from William Green and Gordon Swanborough.

nose job.jpg

Why laminate? Because I am shocked and ashamed to discover that I have no decent 1/4th sheet balsa! WHAT kind of modeller lacks this most basic of life requirements? The cost, again, of not keeping at the hobby with proper rigor.

 

Edited By John_Rood on 19/03/2016 21:42:39

J.H. Rood20/03/2016 00:53:05
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165 forum posts
201 photos

In hopes of getting things straight and true: Identifying reference lines and using them to secure alignment of this (important) forward fuselage module. I'm sorry again about some images flipping sidewise when I upload them to the website ... I don't understand why this is happening.

1.jpg 2.jpg

3.jpg 4.jpg 5.jpg 6.jpg 7.jpg

J.H. Rood20/03/2016 01:05:18
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165 forum posts
201 photos

Each joint is glued now with Super-Phatic and all looks straight and true so far, as in, the lines all meet up centered and square as I'd hoped they would!  

Overnight I shall keep the weights on and pins in so things will hopefully stay in place as the moisture in the glue evaporates... things pull, twist, breathe...

8.jpg

Edited By John_Rood on 20/03/2016 01:09:46

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