Airfix 1:24 Spit Vb: was "newbie questions" now building again

[xffw45343tg]

Hi.

Having not started anything for (ahem) quite a while, I was persuaded by my daughter to help her build a 1:24 Spitfire that I'd given her some time ago. We all know that this kit shows its age but we're not entirely put off just yet. The plan is to stick to OOB as far as possible in the interests of making it to the finish line. The monster's tasks are to cut things off the sprue (she's getting good), delegate fitting to me mostly (can't be doing with all that filing stuff), do sticking, do painting (except when she should be doing homework etc in which case she sometimes delegates) and doing the obligatory swooping the taped together assemblies around the room making machine gun noises.

However, her retentive father is getting a little bit frustrated by the general vagueness of the kit but I know precious little about Spitfires so I reckon it is time to ask for help. So:

1) What is part 158 (in step 2) supposed to be? It sticks out from what seems like an additional gearbox cover that sprouts from what I'm guessing is the prop reduction gearbox. Few of the Merlins I've found have this extra gearbox and none of them have a shaft coming out of it.

2) What's the story with the coolant header tank (part 9)? All pics seem to be natural aluminium (not matt black as called out) and none are just hoop shaped. Every Merlin seems plumbed differently.

3) Are we right in going for semi gloss black for the engine rather than matt black? Some pics are natural alloy, some gloss black, some semi, but not matt.

4) Humbrol 78 seems much darker than the very pale green found on all the restorations. Just add white to a second coat or go with it?

5) Firewall: Green or silver?

6) We added the electric motor (thanks Jadlam/Amazon) and I spent a long time getting it to sit square within the engine block. However, the practice prop still seems to bind a bit, despite part 5A being smooth as silk. Any top tips?

7) Why are the cannon ammo boxes (? - step 15) optional? Were there 2 different types of fairing? What's right for this kit?

8) Any other suggestions for a "let's build it competently OOB" build?

Thanks in advance,

Kirk (& daughter)

Edited May 25, 2016 by Kirk

[Phil32]

This is a tad vague but on 3) any consensus I recall seeing has been on a glossier black, and on 4) there was a lengthy discussion on here about humbrol 78, end result being it matched some original swatches of aircraft grey-green closely and talk of 'interior green' had been throwing the scent. As ever, lighting plays tricks with paint colour however! I'm just passing through on a mobile here but figured I could post that much as a starter; i'm sure someone will be along soon with more comprehensive info!

[xffw45343tg]

Thanks Phil.

Instinct says just lighten the green and move on.

A couple more things:

9) Magnetos(? - parts 18 and 19 in step3). Black or silver?

10) The landing gear struts are not square with the openings in the underside of the wing. Realistic or warped parts?

Cheers,

K&D

[GREG DESTEC]

I built this kit a couple of years back, and generally it went to gether well. Its "lightly" adapted from the original mark 1 kit so the merlin maybe whatever model applied to the early spits and not the mark 5. All i can say to look out for is the wing assembly attaching to the fuselage. There is a tendancy for the wings to "droop" - getting the correct dihedral needs quite a bit of effort, clamps elastic bands etc. Enjoy your build, its an impressive kit once built up.

[Work In Progress]

It really does need some sort of stub spar to set the dihedral and keep it where it needs to be.

[xffw45343tg]

It really does need some sort of stub spar to set the dihedral and keep it where it needs to be.

I'd thought about that. The obvious seemed to be to attach a spar to the base of the firewall, but it looks like this would interfere with the main landing gear forward mounting point. In the real thing, is the spar forward or aft of the firewall and does it incorporate the landing gear bearing?

I guess we would need something shaped a bit like this: \_/ (though with a tad less dihedral). Not sure how to make it sufficiently accurately so as not to make the problems worse (i.e. centre section is a smidge too short, it won't meet the lower wing skin). Anyone gone the spar route before and done all the learning for us?

K&D

[xffw45343tg]

I built this kit a couple of years back, and generally it went to gether well. Its "lightly" adapted from the original mark 1 kit so the merlin maybe whatever model applied to the early spits and not the mark 5. All i can say to look out for is the wing assembly attaching to the fuselage. There is a tendancy for the wings to "droop" - getting the correct dihedral needs quite a bit of effort, clamps elastic bands etc. Enjoy your build, its an impressive kit once built up.

The particular additional parts (157, 158) seemed to be on a "Mk V differences" sprue, but there seems to be an enormous variation in Merlins. I was looking here for engine pics but don't know if this is the engine type we should be modelling. Can open, worms everywhere!

K&D

[gingerbob]

Ah, having found the instructions online, I think I can answer some.

I believe Part 157 is the gearbox for the Coffman cartridge starter, which was on the Merlin XII (Spitfire Mk.II) and also perhaps some Seafires (Merlin 32 maybe?)- but I may be wrong about that part! It was also used to drive the cabin pressure pump on the Merlin 47, used on the Spitfire Mk.VI. Part 158 is the "driveshaft", a rather crude representation by the look of it. I think some Mk.V engines (Merlin 46) had some evidence of this gearbox, if only a bulge in the crankcase, which is why the blister on the starboard side was retained on some aircraft even though there was "nothing" underneath. But remember, this is from the hip, so I may be rather inaccurate.

Don't know about the coolant header tank, which I believe had a plate of armour protecting it from ahead (on Mk.Vs).

I'm guessing that the cannon ammo drums are optional either: to suggest that they've been taken out for re-loading, OR that there might be an interference problem if you're closing the hatches (in which case you ain't gonna see 'em anyway).

Don't know what parts 18/19 are, or what color. My guess is black (and yes, Merlin should be a "nice" black, don't overdo the gloss on a model, though or it'll look like a toy). To be honest, I like my Merlins serviceable, cowling closed, and ready to scramble, so I never worried that much about mysterious gubbins! What I do know is from trying to understand Spitfire, and therefore engine, development.

I'm not quite sure what you mean about the gear legs "not being square with the openings". They angle forward and are nearly perpendicular with "the ground" from a front-view, so neither vantage would make them "square" with the wing. On the real thing, a pintle (sticky outy thing, the "axle" for the gear leg) bolts onto the aft face of the spar, and the gear leg goes on that. The pintle is at a weird angle to make the gear leg go where it needs to both up and down.

The spar carry-through is on the front face of the firewall. You can see it pretty well here (first photo, which gets bigger if you click it), and that photo also shows the header tank pretty well. It's a Mk.IX, but will still give you the idea.

Hope this helps!

bob

[Phil32]

I've seen a completed one of these recently and am reminded, yes the wing droop does make the kit look quite 'off'. This may be curable by glueing the top halves of the wings to the body before adding the bottom halves?

[gingerbob]

I wouldn't rely on that- I think adding a spar is a great idea- too much expanse of somewhat flimsy plastic!

bob

[xffw45343tg]

Thanks Phil and Bob to your detailed explanation of parts. Think I should leave the pressure pump driveshaft off and hunt around for some scrap for a spar. I'm thinking that if it runs as far as the outboard extremities of the wheel bays that should be enough. There's going to need to be a slot cut in the surface to which the upper wing skin attaches at the root and I might have to incorporate a hole for the gear pivot.

How to explain the 'gear strut alignment' thing better. Hmm. Probably best to post a picture but in the absence of available time, I'll try and explain. The gear strut is pivoted at its inboard end on the aforementioned pintle and has the wheel at the other end. The cutout in the lower wing skin consists of a circular bit for the wheel and a rectangular bit for the strut. On the model, the port strut does not pass though the rectangular hole in the same axis as the rectangle - it's more like on the diagonal. I only tried this side since it had fallen off the sprue and I didn't want to lose it and it may well be that the starboard side is better aligned. I just wondered whether the lack of alignment of strut and hole was intentional.

K&D

[xffw45343tg]

Hello again everyone.

We got a bit stalled on the wing spar bit but finally took a walk down to the model shop yesterday to seek out a bit of metal.

Came back with a length of rectangular section brass which seemed like it would be a simple solution. I'd carefully measured the height of the space between the wing skins at the root of 11mm, near as makes no difference, so went for 3/16 x 3/8 section (4.76 x 9.53mm).

However, we have 2 problems:

1. The wing tapers in section. Quite a bit. We put a bit of blutac in the gap, squashed the wing together and then measured it and found that though it is 10.6mm at the forward undercarriage spigot, it is down to 5.8mm by the outboard end of the rectangular opening (ammo cartridge chute?).

2. The wing has dihedral. How much? If we try to bend the brass, there is a reasonable chance that it will buckle.

Perhaps I didn't think this through. I suppose I could use the rectangle for the central section and then "plug in" a tapered angled section (made of another bit of brass) rather like the 1:1 construction. Or maybe we could make v cuts in the rectangular tube and see if I have sufficient soldering skills to make the resultant cut & shut strong enough for the job.

Suggestions?

K&D

Edited May 15, 2016 by Kirk

[woody37]

Hi Kirk,

Just noticed this thread.

I did the 1/24 kit a couple of years ago and put some details in around how I made the spar. I made a paper template first before transferring to plastic. I got the dihedral by tracing over the top surface of a wing front profile drawing.

Hope this helps..

http://www.britmodeller.com/forums/index.php?/topic/234963155-airfix-124-spitfire-vb-decals-on/?p=1666593

Cheers

Neil

[xffw45343tg]

Thanks Neil. Checked out your thread - lovely model. I reckon we should copy your boxed in wheel wells. Big improvement. .

I did some tinkering whilst Daughter did some revision and will try and post a picture tomorrow. What I think I'm going to do is cut the rectangular section so that it is the width of the fuselage at that point. I've cut a couple of tapered quadrilaterals (rhombuses I reckon) out of some thickish Perspex that I found in the stash, with the taper to match the blu-tac pattern. The idea is to file an appropriately shaped spigot on to the ends of each so that they match the dihedral on the inside skin of the wing when slotted into the brass section. I can then hand over to the registered keeper/glamourous assistant and get her to epoxy this spar to the lower wing and learn about a new adhesive. Need to figure out exactly how much of the undercarriage supports will have to go (all of the forward ones I think) so that the spar can fit in as much of a realistic position as possible. This will mean a new pintle bearing (a.k.a "hole" of approximate orientation).

Incidentally, where is the attachment on the real thing? Is the spar forward or aft of the firewall? If I remember correctly they made a big deal of this on the "Guy Martin builds Spitfires" programme but I can't for the life of me visualise the arrangement and position of components into which Guy's tapered bolts fitted.

Like I said, I'll try to get a picture or two up tomorrow to explain where we're at. Thanks for bearing with the wordy alternatives so far!!

K&D

[xffw45343tg]

Here's the 1st picture:

I realise that in addition to sorting out the undercarriage bearings, we're going to need holes in the spar for the gun barrels to pass through.

[xffw45343tg]

Quite pleased with it so far:

I went with a 6 degree dihedral and something like 1.5 degrees of taper. Spar is as stiff as you like so I think it's going to do the job nicely. The Perspex is a wee bit thinner than the hole in the brass tube so the tips of the spar can move fore & aft at the mo, but it's nothing a small shim of styrene card (or even just epoxy) won't sort out. The diagram was handy when sanding the ends of the Perspex to make sure the spigot fits at the right angle. If anyone wants a copy, send me a pm.

Holes for armament should be pretty easy but the undercarriage mountings less so. They'll fall right at the ends of the brass section and I'm going to have to think of something cunning to get the drill lined up in the right orientation. A proper engineer would probably knock up a jig, but I'm not so I might make do with some pencil guide lines and a guide hole that I then file out to size.

Cheers,

K&D

[xffw45343tg]

Calling it done on the wing spar now:

In the end the holes for the cannon and inboard gun were pretty straightforward to drill then, in the case of the cannon hole, enlarge with a file so that the barrel will fit through. The holes make the barrels sit a little higher up than they do without the spar there and they don't locate positively since I've had to remove the little lugs moulded on the lower skin to enable the spar to make contact evenly along its length. However, I think this is something we can deal with when it comes to lining up the cannon fairings later.

As suspected, the really tricky bit is sorting out the main gear pivots. The main problem seems to be that the kit "horseshoe" lugs into which the gear legs are supposed to click are simply not very accurately positioned - the left one being worst.

(Just spotted in this picture that the legs are in the wrong sides for the photo!!)

As you can see, the forward lugs have to be completely removed to fit the spar (along with most of the moulding that is meant to hold the gear up). I've done my best to position the holes in the spar on the forward end and used the file to get them to the right angles in the XY and XZ planes with a little bit of "wobble tolerance", but the slightest misalignment on the aft end means that the legs just don't follow the right retraction path to line up with the cut-outs in the wing skin. I think the best approach is going to be to cut the aft bearings off entirely and replace them with a bit of brass angle which we can set into positon in epoxy. If I had to do this all over again, I'd contemplate making something a bit more like the 1:1 construction with the pintle threaded into the spar.

What I'm most pleased about is that we can return to "daughter-made" mode now. It would have been a bit over-optimistic to expect her to have fabricated the spar but she's followed what I've done and should learn a bit from gluing and clamping it in place. All in all, the model will be significantly improved the addition though. I'll try and get a picture later of just how much droop is being taken up. Today's breakfast project meeting concluded that we should crack on with this after school. I feared that we were heading down the "parent takes over" route but can justify it in my own mind by regarding this as me making a few more kit parts for her to assemble.

Watch this space for progress.

K&D

[Spitfire31]

Hi Kirk,

Just noticed this thread.

I did the 1/24 kit a couple of years ago and put some details in around how I made the spar. I made a paper template first before transferring to plastic. I got the dihedral by tracing over the top surface of a wing front profile drawing.

Hope this helps..

http://www.britmodeller.com/forums/index.php?/topic/234963155-airfix-124-spitfire-vb-decals-on/?p=1666593

Cheers

Neil

I said it then and I'll say it again, Neil: that's a beautiful treatment of that venerable old kit!

I'm also impressed by the fact that you didn't string an aerial wire between the antenna mast and the rudder, in spite of the box art erroneusly showing one!

Starting with the Mk V (or perhaps even Mk II) the radio set was changed to a VHF one, which also meant that its shorter antenna was completely integral to the old aerial mast. No wire.

http://spitfiresite.com/2010/04/spitfire-masts-and-aerials.html/2

Good luck with the spar and the rest of the build, Kirk!

Kind regards,

Joachim

[GordonM]

Bit too late, but way back in the mists of time (70's) when the original wunderkit Mk1 came out I remember reading either the Airfix book on building and improving it by Gerald Scarborough (most likely, despite not standing a cat in hells chance of ever affording iit, but council libraries are dream factories!) or in an Airfix Annual how to make a plastic card spar to hold the wing alignment?