PSS A-4E 'Top Gun' Skyhawk

[Phil Cooke]

The day has finally arrived!

I wanted to make a timely start on my A-4 build and get the blog section underway with a short update today, 1st March, as we commence the 2016 PSSA Mass Build! Many thanks to everyone who is taking part, with 38 builds registered we should be in for an exciting event when in just over 6 months time we meet on the Great Orme 10th/11th September...

After much deliberation, I've decided to model the famous 'Aggressor' A-4 as flown by 'Jester' in the Top Gun movie... something a little different from the grey and white scheme of the prototype model completed by Matt Jones and myself last year, whilst still allowing a 'stock' build as per the drawing and Traplet woodpack.

I've made a modest start today on the fuselage, nothing more than laying up the fuselage sides which are made up from 3 pieces of 1/8" medium balsa. I've started here as I wanted to point out that the woodpack contains the small faceted sections which help form the wing T/E lip. If you've purchased the woodpack, these can be found on Sheet 1A.

One side at a time I pinned an entire sheet of medium 1/8" balsa to the plan aligning the bottom edge with the little solid arrows on the plan - you'll find that a 4" x 36" sheet of balsa overhangs the fuselage length by ~1/2" front and back - leave this overhanging equally both ends which will allow for some curvature later in the build.

I cut a 640mm x 30mm length of 1/8" balsa, similar grade, to glue to the top face of the 1/8" sheet with the laser cut faceted piece at the bottom. Once aligned, I taped the 3 pieces together flat on one side, then opened up the tape 'hinge' and glued with PVA. Once repeated, both sides were laid flat with a sheet of paper between them before they were pressed to cure over night.

The full depth one piece fuselage sides will be trimmed carefully to shape once dry. There, I said it was a modest start... but a timely one.

Good luck with your build, I look forward to watching your A-4s progress on the forum!

[Mark Kettle 1]

Nice start Phil , and quick 1:49 mintue/secs into March, at this rate you'll be done by the 2nd of March.

[Steve Houghton 1]

Excellent Phil. I shall be watching this thread intently so I know what it is I'm supposed to be doing. This is my first kit/plan balsa build since about 1980, so I haven't got the foggiest what it is I'm supposed to be doing or where to begin.

My kit has arrived but I haven't had a chance to open it up and lay it out as I have another project on the bench just coming to a conclusion this week, then it's all systems go and look to see what sheet balsa I need to buy.

Btw, what sizes of sheet balsa do I need to buy? I'm guessing you've probably already listed these requirements Phil? I know how organised you are.

Cheeky aren't I

[Andy Meade]

Is it done yet?

Steve - from the "Introduction" thread : 

WING

Wing Spars – 1/8” x 1/8” SPRUCE strip – 4 Off

Wing Skins and webbing – 1/16” balsa sheet – 7 Off

Sub L/E – 1/8” x ½” balsa strip – 2 Off

Sub T/E – 3/16”^h x ¼” balsa strip - 2 Off

Wing L/E – 1/4” x ½” balsa strip – 2 Off

Wheel Bays – 5/8” balsa sheet – 1 Off

Ailerons – 1½” x 5/16” T/E Aileron Stock - 1 Off

Wing Dowel – ¼” dia x 3” Beech – 1 Off

Scrap infill required ¼” balsa sheet, 1/8^th balsa sheet, 1/8^th light ply sheet

M3 torque rods – 1 Pair

6mm nylon wing bolt and captive nut – 1 Off

 

FUSELAGE

Fuselage Sides/Intake skins – 1/8” balsa sheet – 4 Off

Decking – ½” SOFT balsa sheet – 1 Off

Decking – ¼” balsa sheet – 1 Off

Doublers – ½” x ½” balsa Triangular – 2 Off

Doublers – ¾” x ¾” balsa Triangular – 1 Off

Scrap infill required – 1/8” balsa sheet, ½” balsa sheet

1 Sullivan type Snake (elevator actuation)

 

TAIL

Fin post – 3/8” x ½” HARD balsa strip – 1 Off

Elevator – 1¼” x 3/8” T/E stock – 1 Off

Elevator actuator – M2 pushrod and 5mm dia brass tubing

 

You will also need a 1/12th scale jet pilot - just a bust as per the plan. No PSS model is complete without a pilot!

Edited By Andy Meade on 01/03/2016 08:53:01

[Phil Cooke]

Ahhh, I see Andy beat me to it with the list, many thanks. Commuter travel and work has meant I wasn't able to react swifter. Yes Steve, the list above should be comprehensive for the material needed in addition to the Traplet woodpack, I gave this some careful thought prior to compiling it in the 'Intro' thread. Hopefully there will be no 'holes' in my working.

Mark/Andy, a timely start was important but I won't be breaking any timescale records with this build - after all we have a full 6 months to construct and refine this model.  Using the woodpack, folk will see the model assemble quite quickly. My build blog won't be extensive, the write up is already printed in the Feb and March RCMW mags covering the build in detail, but I will bring out any details that might aid progress further.

The finish on this model will be quite different from the prototype which was film covered all over and had a solid balsa cockpit. Here, for the camo Agrressor I intend to glass and resin the airframe then spray, as a learner prior to the same job to follow on the A-10. The clear canopy should allow a little detail in the cockpit but it's not too roomy in there - just enough room for 'Jester's' sandwiches and his A-Z of Miramar.

Edited By Phil Cooke on 01/03/2016 11:19:09

[Steve Houghton 1]

Cheers Andy

[Steve Houghton 1]

Phil - Can I assume all the wood strip & sheet listed is in 36" and not 48" lengths?

[Steve Houghton 1]

Don't worry Phil, I got it now

[Andy Meade]

He's slacking again isn't he? Can't even run his own build thread. Tsk.

For reference, wood is 36" x 4", medium balsa, unless otherwise stated

[Steve Houghton 1]

Ta muchly Andy. Wood ordered for delivery tomorrow. I've no excuses now!

[Bob Jennings 1]

Hi Phil,

Haven't got electrickery in the shed yet, but I'm starting my twin build this week.

Have a feeling this event will be amazing, judging by the interest so far.

[Martian]

Will be watching in silence and enjoyment

[Peter Garsden]

Will also follow this with interest. I have my woodpack, plan, and canopy all ready and waiting.

Just short of a Liz Earle moisturiser bottle and the February edition of R/C Model World. I've got the March edition but not Part1. It was too late. I have emailed Traplet to see if they could send one to me, but I am not optimistic.

Still after a lost foam Carbon Jart it should be a doddle.

[graham Gilliver]

Good start Phil,

from being a day ahead I am now a day behind and not likely to make a start for a couple more now due to work requirements. but I watch with envy.

the december issue of RCMW is on the shelves here at the moment so may have awhile to wait for the second article too. thanks to you I am able to read the first one.

local printers machine is broken down so will have to go further afield to get my drawings for the T'bird mods done.

If some one else is planning the gold RNZAF 50th anniversary colours I will use the test colour scheme for that aircraft.

How do I create an album so I can put a picture here? Cheers Graham

[graham Gilliver]

[graham Gilliver]

almost figured it out . ta it is a bit close to the common grey/white with the associated viz probe but better than two doing the same scheme. G

[Phil Cooke]

I've cut the 1/8" fuselage sides to shape and marked them up on the inside (Left and Right pair) with accurate former and doubler positions to aid assembly. Easy enough to cut from the plan by extending the lines, they are all straight sided facets apart from the wing saddle... here the woodpack helps no end!

Once the former positions are marked accurately from the plan you can overlay the laser cut 3/16" doubler and trace round that for the perfect curve.

2 fuselage sides, marked up ready for assembly

A bit of detail at the front of the wing at F3. Note how the fuselage side allows for the 1/16" ply face on the rear of F3.

Don't forget to add the little laser cut faceted piece which helps form the step at the wing T/E!

Its a good time now to cut the 3 slots for the air intake formers before the fuselage sides get the doublers and triangular section added. Time now to find the triangular strip stock and add the doublers.

[Phil Cooke]

I've added all the fuselage triangular section and laser cut doublers tonight, creating a left and right handed pair.

A few detail shots... below - 1/4" nose doubler sits ontop of F1 and against the front face of F2.

Below - Important to leave a gap between the 1/2" front base triangular section and the 3/16" wing saddle doubler to allow the 1/16" ply doubler of former F3 to slip in during assembly later.

Below - triangular section extent and 3/16" doubler at wing T/E F7 position.

[Harry Twist]

Hi Phil,

Very tidy work and rapid progress already. Can I ask - for all your balsa-balsa joints are you simply using PVA?

Are there any joints where you will use CA?

Not gone mine rolling yet - middle of next week sees me getting a couple of days off so will aim to get stuck in then.

Regards Harry

[Phil Cooke]

Morning Harry, yeah in general I just use a well trusted PVA - Evostik Green Wood Adhesive in my case. I will utilise cyano later in the build, on the wing mainly, its best for sticking ribs - its wicking ability is very useful - and on the fus there may be a bit used in conjunction with CA where a 'fast grab' is needed to help as a third hand - adding the air intake skins was one area I recall from the prototype build.

[Phil Cooke]

Not touched the A-4 in a couple of nights as I've been late in from work and too tired to start... a little more done this evening worthy of report...

I've made up the 2 composite formers F3 and F6. Note how when the 1/16" ply doubler on F3 (right) is positioned correctly (so the battery tube and wing dowel holes align) it overhangs the balsa former by 1/4" at the bottom.

The pre-machined hole in the balsa half of F6 (left) didn't quite perfectly align with the hole in the 1/8" ply half - having glued them together I opened up both a little to the size of my chosen captive nut and compress fitted the nut down into the ply side of the former. You will find drilling 4 small pilot holes for the nuts 4 'teeth' helps fit the nut without cracking or distortion.

I made up the battery box using thin wicking cyano with the sides held square, one at a time. This assembly in particular is a lovely example of the accurate laser cutting, the box formed perfectly in no time at all. Once glued, its important to mark the box up with an axial centreline top and bottom, and the positions of formers F2 and F3 on the side walls. Read the positions from the plan. Note the formers are not square to the box, which sits at an angle (nose down) in the fuselage. Marking up accurately is important now as soon we will be gluing this assembly up in free space.

I did a dry fit - it was about now I remembered I had no F2 former in my laser woodpack, and I'll have to cut my own from 3/16" balsa - so just a dry assembly shot now. Regarding the 1/4" fuselage floor, its a good idea to leave this a little large on the sides so later on you can pin this down to the plan from OUTSIDE of the fuselage walls. I left mine 1/4" bigger than needed at the sides...

Another dry fit shot. Note the ply on the back of F3 seats down to the plan and butt joints against the back of the fuselage floor sheeting. Right, time to make an F2 then all this can be reassembled and glued up!

Edited By Phil Cooke on 09/03/2016 22:36:53

[Andy Meade]

Lovely and neat. I swear you have a separate photo booth for taking pictures of builds. This area is far too tidy to be a production environment

[Phil Cooke]

to be fair I took these photos last night at the end of the working session, not mid task, so I did have a quick dust down and moved some tools before the shots were taken. You do 'dust down' and put your tools away at the end of each session, dont you Andy??

[Andy Meade]

Nope - I haven't got any odd OCD problems!

Leave 'em where they fall

[Mark Kettle 1]

I've seen Phil's workshop, only a standard width garage, he does well and work's hard to get the photo's and shot's he show's, I expected to see a couple of fancy lights or soft defused lamps, no from what I could see just a strip light, no reflectors. Nice build by the way Phil .