Revell 1/32 Spitfire Mk.IIa kit - Built as a 54 Sqn Spitfire Mk.Ia.

[Derek B]

Looking forward to that. Will you correct the length of the fuselage ?

 

Good question Pascal - I have been deliberating on this one a bit. From a purist point of view, and probably as a personal preference, yes, I would. However, I suspect that most modellers will ignore the error as it may be too much trouble for them to correct (the internal fuselage spinner prop shaft support makes it very difficult to shorten the nose from the front back; the kit length error on the kit is between the rear of the exhausts and frame 5 firewall bulkhead).

 

I have not decided yet if I want to correct it or not? - if I do decide to correct it (or at the very least indicate where I think it should be shortened), it will simply be to show my preferred method of doing so and is totally optional for everyone else.

 

Derek

Edited May 5, 2017 by Derek B

[Derek B]

Some Revell spinner Vs Hasegawa spinner back plate diameter observations:

 

A quick dimensional check of the spinner base plate diameters of the drawing, Revell and Hasegawa kits has disclosed the following:

 

Drawing: 19.5mm to 20.00mm (Probably due to copy distortion)

Revell kit: 20.50mm

Hasegawa kit: 19.8mm

 

This identifies the Hasegawa spinner back plate as being smaller than the Revell one by - 0.7mm.

 

The ever helpful Edgar Brooks has confirmed that the Mk.IX Spitfire front former drawing shows a dimension of either 24.4" or 24.6", which is 19.36mm or 19.52mm respectively in 1/32 scale.

 

He also states that the Monforton publication indicates 24.15" for the same area, which is 19.16mm in 1/32 scale. He also mentioned that a friend measured a Spitfire Mk.IX spinner diameter, which was found to be 24.25" (19.24mm in 1/32 scale).

 

If all of the full size measurements are averaged out to produce an approximate theoretical spinner backplate diameter, with a degree of uncertainty of accuracy, it comes out as 24.6" diameter, which equates to 19.52mm - for the purposes of modelling, this is probably a pretty good base line figure to work from.

 

When offering up the Hasegawa kit spinner to the Revell kit nose, it is apparent that it is slightly undersize to the nose spinner backplate location (and conversely, the Revell spinner is fractionally too large in diameter when offered up to the Hasegawa kit). What exaggerates this effect, as already noted by yourself, is that the spinner backplate location at the nose of the Revell kit is eccentric - the diameter is deeper vertically than horizontally (effectively slightly oval), measuring 21mm vertically and 20.6mm horizontally.

 

The good news is that if you wish to use the Hasegawa spinner on the Revell kit, you only need to reduce the nose diameter by just over half a millimeter and reshape the rest of the surrounding area of the nose to match (using the George Cox drawings as a guide), which will improve the look of the nose in this area because the curve of the nose to the spinner will be slightly less abrupt.

 

In profile shape, the Hasegawa spinner mactches the drawings quite well in terms of size, shape and diameter (which in common with the rest of the Hasegawa kit continues to show the greatest accuracy all around when assessing suitability for a BoB Mk.I aircraft of all kits, including the Tamiya kit). The Revell spinner could be modified, but would require reshaping at the front (I have not looked at any AM Rotol props as yet, nor the Revell Hurricane Rotol prop - I must check this out sometime).

 

Derek

Edited May 5, 2017 by Derek B

[Derek B]

Kit corrections

 

Here is where I start to correct the observed anomalies with the Revell kit. The major issue with the kit appears to be the over deep wing section that causes the whole of the fuselage to be too deep from approximately the front of the underwing radiator position all the way to the bottom of the propeller spinner. This extra depth may only be in the region of 1.5mm, but it is enough to alter the overall shape and impression of the aircraft in this area.

 

Additionally, the shape of the upper fuselage between the front of the windscreen forwards to the frame 5 firewall bulkhead (essetially the area of the armour plate protection over the fuel tank) is also more angular than it ought to be (it should form a nearly constant radius in cross-section). In plan view, the fuselage width is also wider than the drawing from the nose aft to just after the cockpit - the rear fuselage is about right.

 

The fuselage is nearly 2mm too long, the area of error being identified as aft of the exhausts, which misplaces the cockpit too far aft and the positional location of other panel lines and key features (which in themselves are out by small, but varying degrees as well). 

 

The cockpit canopy has varying size and shape issues that need to be tackled piecemeal. The aft glazing is too deep by nearly 2mm. The length of the glazing is about right, but the aft edge of the entry door is too far forward, leaving a non-existant space notch between the glazing and door edge. The overall length of the Revell kit cockpit from the front of windscreen to the rear edge of the aft glazing agrees pretty well with the drawings and those of the Tamiya and Hasegawa kits at around 44mm, so it is the proportions of the various components within this length that vary, and because of the additional fuselage length, is also displaced too far aft.

 

Overall, the features of the Revell Spitfire IIa are well represented on the kit, but their location, distribution and proportion is not always accurately dispersed, so it is difficult to accurately align everything up correctly with drawings or plans of reasonably good or known accuracy.

 

Any other observations of kit anomalies will be noted (and fixed) as corrections continue...

 

Correcting the upper fuel tank fuselage shape forward of the canopy

 

The technique that I will be employing to correct this (along with the fuselage width and wing depth) is very simple - I use brute force to bend the plastic into submission in order to obtain the correct shape and alignment!

 

The Revell kit plastic is relatively soft to a degree and can be worked, bent and manipulated up to the point that fatigue stress shows the start of a fracture occurring (this would also be true of any IM kit plastic).

 

The picture above indicate the main area that requires manipulating (lilac) in order to remove the angular form and reshape it to the correcr radius shape. The numbers represent the stage order in which I carried out the reshaping.

 

 

Stage 1 is to gently work and bend out the angular part of the fuselage top close to the windscreen - stop when the plastic colour alters to white, as continued back and forth bending fracture the area otherwise.

 

Stage 2 shaping. Manipulate the rest of the upper fuselage up to the firewall in order to obtain as regular curvature of the fuselage top back to the windscreen as you can. Because of the stiffness (and thickness) of the kit wall plastic at the very top of the fuselage immediately in front of the windscreen, it may not be possible to achieve a constant curvature in this specific area. However, it should be possible to greatly improve the fuselage shape in this area and get it close to that of the Tamiya and Hasegawa kits.

 

 

 

 

The above four pictures show how the kit fuselage appears after I have beasted it for a while - as can be seen, without any further correction, it is not far off to that of the Tamiya kit fuselage in terms of correct radius (you may also have to slightly bend up the top tine of the fuselage at the centre line in order to keep the upper line of the fuselage top matching the drawing side profile, but this is only very minor tweaking). Once assembled, this area can be  filed, filled and sanded and then a thin piece of plastic card made and fitted to cover the area to represent the fuel tank armour plating.

 

To be continued...

Edited May 5, 2017 by Derek B

[Derek B]

Correction of fuselage width

 

According to the plan view of the drawing, and by comparison to other Spitfire kit dimensions, the Revell fuselage is a little too wide, specifically from the spinner backplate at the front of the nose aft to just aft of the cockpit area. The Revell kit rear fuselage is generally acceptable in terms of width and shape. As the forward part of the fuselage cross section is to some extent masked by the overhang of the engine upper cowl edges, the main area that the additional  fuselage width is noticeable is from the frame 5 firewall bulkhead aft to just behind the cockpit area, so this is the area that I shall concentrate on correcting.

 

The lilac colour indicates the approximate areas where the fuselage requires manipulation in order to locally reduce the overall width. 

 

Using similar techniques to those employed to correct the upper fuselage shape (i.e. Finger and thumb pressure) carefully, but gently, manipulate the fuselage side by applying pressure to force the fuselage side inwards at the mid-point (the moulded fuselage longeron datum point is a useful guide here). Work your way methodically along the fuselage from frame 5 at the front to just behind the cockpit until you are satisfied that it looks less curved and therefore reduced in width.

 

Results of Revell kit fuselage width reduction after manipulation compared to the Tamiya kit fuselage on left. 

 

Similar view showing comparison of Revell (right) and Hasegawa (left) fuselages. It may be necessary to alter the shape of the internal frames and cockpit parts to accommodate the modified fuselage shape, but we'll cross that particular bridge when we get to it - still having fun?

 

Correction to the wing root fillet fairings

 

These look too flat and lumpy in shape towards the rear third of their length and could do with blending into the rest of the fairing. Luckily, there is sufficient plastic material in the wall thickness at this point to allow this to happen - I will show the results of this later.

 

Correction of fuselage length

 

The only major alteration possibly required to the fuselage (and this is entirely dependent upon the individual modeller) is to decide whether or not to shorten the fuselage by 2mm to bring most things back into alignment - my guess is that the majority of modellers will not do this. I have not yet decided if I will do this or not for this assessment, but if members wish me to do this to illustrate how it can be done, then I shall consider it.

 

To be continued...

Edited May 5, 2017 by Derek B

[D.B. Andrus]

 

 

The only major alteration possibly required to the fuselage (and this is entirely dependent upon the individual modeller) is to decide whether or not to shorten the fuselage by 2mm to bring most things back into alignment....but if members wish me to do this to illustrate how it can be done, then I shall consider it.

 

 

 

Please consider doing so, Derek.

 

Excellent tutorial!

 

Cheers,

 

D.B.

[Derek B]

Wing depth correction

 

This is the major correction needed to the kit in order to correct the overly deep and portly appearance of the fuselage from the underside of the wing centre section to the nose when viewed in side profile.

 

As the wing root is over 1mm deeper than drawing (and both Hasegawa and Tamiya kits), but the relative position of the uppermost part of the wing section is approximately correct, it means that the excess depth can only be reduced from the lower wing section.

 

Iain Ogilvie applied a similar technique (albeit more elegantly applied) to correct the shape of his Revell Spitfire kit wing depth - a solution that we both arrived at separately (see here: http://forum.largescaleplanes.com/index.php?showtopic=51695&page=10).

 

Using the Tamiya kit wing as a reference (which is the most accurate representation of the correct lower wing shape of the Spitfire), it can be seen just how shallow and flat it is ina areas, particularly from the front spar aft to the identification light (this is the area that will be attempted to be replicated on the Revell wing section). In comparison, the same area on the Revell kit is practically a continuous curve from leading edge to trailing edge.

 

This picture clearly identifies where we need to manipulate the Revell kit wing and apply pressure in order to correct the depth anomaly and make it look more like the Tamiya kit wing. It should be noted that during this process, it is likely that the applied force will stress crack the front centre of the wing (unavoidable when you are going to try and flatten out a double curvature piece of plastic), but at this is located in an hidden area above the carburettor intake scoop, it will not be seen when we are finished.

 

 

 

 

The above photographs show where I applied pressure to correct the wing shape.

 

 

 

This is how it looks after bending to a flatter shape that is close to the shape of the underwing section of the Tamiya kit kit. As can be seen, the underside of the wing is now noticeably less curved, flatter in the centre section and is now much closer to both Tamiya and Hasegawa kit wings in appearance.

 

And just to confirm that the correction is successful, a measurement of 39mm was recorded (Drawing: 39.65mm, Tamiya kit: 38.8mm and Hasegawa kit: 39.32mm).

 

To be continued...

Edited May 5, 2017 by Derek B

[D Bellis]

What about styrene's natural tendency to return to its original as-cast shape? Without something to hold the new shapes, will not the bent parts eventually drift back to their original shape over time?

 

D

[Derek B]

Wing depth correction (Continued)...

 

Now that the depth of the Revell kit lower wing centre section has been successfully accomplished, other areas around it also require attention in order to make everything to correct (revised) shape and fit once more. 

 

As we could not modify the upper wing, bending the lower wing flat effectively makes the internal wing stiffeners a banana shape which means that they will now be too high in the middle and too low at the leading and training edges of the wing - this will interfere with the fit of the upper wing sections and undercarriage bay walls. To remedy this both the internal integral wing stiffeners and wheel well bay walls have to be reduced in thickness. 

 

The two other immediately obvious things are the rear of the wing fuselage mating section and the lower nose cowl fairing where the integral carburettor intake scoop mounting meets the lower wing; both of these will now be at the wrong angle and will no longer correctly mate together. Fortunately, the fix is once more easy - bend them until they do fit.

 

With the wing adjusted and flattened, it can be seen the internal moulded integral stiffeners are now no longer parallel to the wing chord, but are bowed. This effectively causes the stiffeners to mask the rear of the upper wing location tab slot.

 

With the upper wing placed over the adjusted lower wing, the bowed nature of the stiffener is now very evident. This will be corrected by reducing the thickness of the stiffeners on both sides.

 

And this is the effect with the internal stiffeners in the lower wing not reduced in height (the upper wing holds to lower adjusted wing away from the fuselage due to the bowed stiffeners, leaving a gap at the wing leading edge).

 

Inner moulded stiffer before reduction of the height.

 

Stiffener reduced in height and now parallel throughout its length across the wing chord (reduced from its original maximum height of 3.25mm at the point of greatest depth down to approximately 2mm).

 

Fit of the upper wing once the stiffener has been reduced in height and made parallel.

 

As well as reducing the lower wing internal moulded wing root stiffeners in height to enable the leading edge wing gap to be closed, the same thing is necessary with the undercarriage wheel well bay walls. Either upper or lower (or both) wing walls can be adjusted to suit - I chose to lower the upper wheel well walls to match the existing lower wing wheel well walls (the above picture shows the adjusted upper wing on the left and the unadjusted upper wing on the right). Carefully file and cut away the horizontal edges of the front and rear walls and test fit frequently until the wing leading edge gap disappears with the walls of both upper and lower wing mating without any internal gaps.

 

This is how it looks after the stiffener is reduced in height; the upper wing slots are now free to accept the tabs.

 

Wing gap at leading edge now eliminated and the upper wing fit remains unaffected, but the lower wing, now flattened and adjusted internally, matches the drawing and Tamiya and Hasegawa kits for overall depth.

 

To be continued...

Edited May 5, 2017 by Derek B

[Derek B]

What about styrene's natural tendency to return to its original as-cast shape? Without something to hold the new shapes, will not the bent parts eventually drift back to their original shape over time?

 

D

 

Well D., as I understand it (and I am far from being an expert in this field), injection moulded plastic, which unlike resin, which is cast, is formed by application of theral heat and pressure which alters the molecular structure of the plastic to soften it and form its new shape, which is fixed when it sufficiently cools. Some plastics seem to have a molecular 'memory' property, which when reheated or under extreme pressure, allows the plastic to return to its former primary shape (yogurt cartons are pretty good examples of this).

 

Internal support, which is what Iain has done with his correction, is a good idea as it stiffens the area concerned. In my case, I will rely on the structural integrity of the rest of the airframe itself to hold everything into shape (I may add one or two small plastic support pieces here or there to prevent any stress points or cracks propagating, other than that, no major internal stiffening will occur).

 

Regards

 

Derek

Edited May 5, 2017 by Derek B

[Pascal]

Very interesting solution Derek. What gave you the idea that bending the plastic could solve the shape issues ?

 

(I hope that I've expressed it correctly, it is difficult to write in english what I'm trying to say in flemish. Most people would have taken a Dremel and some sandpaper, but your method is very original and brilliant).

[Derek B]

On 8/22/2014 at 8:11 PM, Pascal said:

Very interesting solution Derek. What gave you the idea that bending the plastic could solve the shape issues ?

 

(I hope that I've expressed it correctly, it is difficult to write in english what I'm trying to say in flemish. Most people would have taken a Dremel and some sandpaper, but your method is very original and brilliant).

 

Thank you for the very nice (but probably unwarranted) compliments (your English is fine and fully understandable to me). Having figured out what was wrong with the kit (as had already been pointed out by other modellers) I considered how best to try and correct it without too much work whilst trying to keep most of the detail.

 

The motivation for this assessment is to see for myself what the main issues are and find an 'old school' cheap and cheerful method to fix the issues (lead by example). I do not consider this to be an expensive kit, but it is good value for the money, and I therefore decided to buy it specifically as a sacrificial lamb for the purposes of this assessment - nothing ventured, nothing gained and if it all went wrong, I have only lost £20.00! (it will never be fully completed and I will buy another one if I wish to make a completed model).

 

Regards

 

Derek

Edited March 16, 2023 by Derek B

[Derek B]

Wing depth correction (Continued)...

 

 

With the lower wing adjusted by flattening it to correct the depth issue, it can be seen that the lower nose cowl oil tank fairing carburettor intake scoop mounting is following the line of the original wing shape and is proud of the revised shape wing leading edge. Likewise, the lower wing trailing edge under fuselage portion also exhibits the same problem.

 

 

The solution - like all of the corrections so far - is to bend both items until they fit properly!

 

 

As can be seen above, these simple correction addresses the main identified kit fault and completely transform the look of the aircraft around the fuselage centre section area.

 

This covers the major corrections necessary to correct the observed anomalies. I will continue to assess the rest of the kit parts and report my findings as I go. Once this is done, which covers kit corrections as it stands for a Spitfire Mk.IIa aircraft straight OOB, I shall provide a guide of how to modify the kit to make it look like a BoB Spitfire Mk.I aircraft.

 

Derek

[desmojen]

Ingenious! Nice work Derek

 

Jen.

[Derek B]

Ingenious! Nice work Derek

 

Jen.

 

Coming from you, that is a big compliment - Thank you Jen.

 

Derek

[Clarkeeboy56]

Been a while since I've posted on here, but I've just read through this thread and have to say what a well thought out and informative thread! Well done Derek! I'll check out Iain's thread on BM and Jen's on here and I think I'll be treating myself to one!