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22a Bodyshell Casting Variation

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Re: 22a Bodyshell Casting Variation

Postby GHOSTHUNTER » Thu Oct 12, 2017 6:55 pm

Here is Nick's picture with early and late versions.

#22a Vauxhall Cresta.JPG
#22a Vauxhall Cresta.JPG (53.33 KiB) Viewed 74 times

Looking at the area all around the axle housing on both models, but more evident on the right model, it gives the impression the tooling for this area was quite complex. Why was it felt the axles need so much bracing when there was already the standard slim curved bracing at extreme edges of the baseplate (I say standard, because this type of brace is seen on several other models in the range).

I also agree with the way the the effect of broken metal suggests a brace, or bracing of some sort may have been there, but on the pre-production models and removed for full production.

I have Three pictures of the supposed pre-pro model in medium Green, but sadly the baseplate is not one of them and nothing can be seen inside through the windows for any top bracing.

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Re: 22a Bodyshell Casting Variation

Postby Idris » Thu Oct 12, 2017 7:29 pm

GHOSTHUNTER wrote:I also agree with the way the the effect of broken metal suggests a brace, or bracing of some sort may have been there, but on the pre-production models and removed for full production.


Removving a brace would have required the addition of metal to the tooling, something which I understand is extremely difficult once the metal has been surface hardened. Removing such a brace would theredore almost certainly have required retooling, meaning a clean finish would be expected.

GHOSTHUNTER wrote:I have three pictures of the supposed pre-pro model in medium Green, but sadly the baseplate is not one of them and nothing can be seen inside through the windows for any top bracing.


That green model is now in my collection but, unfortunately, the photographs are on my home computer. However, I have the idea that the baseplace is the later braced version, meaning that the model is not a pre-production. (I'll post a photograph next time I'm back home.)
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Re: 22a Bodyshell Casting Variation

Postby GHOSTHUNTER » Thu Oct 12, 2017 8:32 pm

It is conceivable the baseplates were all cast with the brace, but then removed by hand before being painted and assemled with the axle/wheel assembly. Any engineering, sub-assembly or mechanical based workplace would have a policy of hand fettling or hand finishing of sub-standard products. Faulty products could be produced for a short while because of a fault with the machinary or the model components. Production would be haulted while the fault is rectified. The faulty items could be rectified by hand at a later date and even by sub-contractors (have been involved in this myself),

If that brace was not cast correctly it would foul the axle making it harder for the Girls to push the axle into it's channel on the base. A quick fix is to have someone break away this brace clearing the path for the axle.

Put those slightly modified bases back into production and they find their way painted Black and placed on to the bodies.

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Re: 22a Bodyshell Casting Variation

Postby DrJeep » Thu Oct 12, 2017 8:57 pm

Removing a brace would have required the addition of metal to the tooling


...is the major flaw in the idea that the brace has been removed. But the front axle on the no-brace model does have an obvious oval indentation that could be a new piece welded onto the mould? I have no idea if adding something to the mould would have been impossible or just very hard to do.

It is conceivable the baseplates were all cast with the brace, but then removed by hand before being painted


...is a really interesting idea. I don't think it explains the same broken look at the back, because surely there would be some Crestas with a back axle brace too?
Attachments
IMG_4537 - Version 2.jpg
back axle
IMG_4537 - Version 2.jpg (85.58 KiB) Viewed 67 times
IMG_4537 - Version 3.jpg
front axle no brace
IMG_4537 - Version 3.jpg (77.83 KiB) Viewed 67 times
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Re: 22a Bodyshell Casting Variation

Postby Idris » Fri Oct 13, 2017 5:14 am

GHOSTHUNTER wrote:It is conceivable the baseplates were all cast with the brace, but then removed by hand before being painted and assemled with the axle/wheel assembly. Any engineering, sub-assembly or mechanical based workplace would have a policy of hand fettling or hand finishing of sub-standard products. Faulty products could be produced for a short while because of a fault with the machinary or the model components. Production would be haulted while the fault is rectified. The faulty items could be rectified by hand at a later date and even by sub-contractors (have been involved in this myself),

If that brace was not cast correctly it would foul the axle making it harder for the Girls to push the axle into it's channel on the base. A quick fix is to have someone break away this brace clearing the path for the axle.

Put those slightly modified bases back into production and they find their way painted Black and placed on to the bodies.


What you say is certainly true of expensive cast components, but i struggle to see Lesney using had-fettling. Many other threads have referred to defective components simply being thrown back into the melting pot, and remember that there were cheaply made items where the profit margin was slight and the buisness model relied on volume production/sales.
I think that if the reject rate had reached unacceptable levels, production of the 22a would simply have been halted until the tooling could be suitably modified.
What we might be looking at is an indication of poor metal flow, in which case the brace (whose purpose has always been unclear) might simply represent an additional flow channel for the molten metal.
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Re: 22a Bodyshell Casting Variation

Postby GHOSTHUNTER » Fri Oct 13, 2017 10:31 am

''What we might be looking at is an indication of poor metal flow, in which case the brace (whose purpose has always been unclear) might simply represent an additional flow channel for the molten metal.''

This would then prbably give us a fairly accurate 'Time-Line' for the base without and then with the brace, but we don't have that do we or am I seeing it/reading it wrong.

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Re: 22a Bodyshell Casting Variation

Postby DrJeep » Fri Oct 13, 2017 6:39 pm

...gives the impression the tooling for this area was quite complex. Why was it felt the axles need so much bracing when there was already the standard slim curved bracing at extreme edges of the baseplate?


After the tiny 21a coach this was the first Matchbox with a separate baseplate and I'm sure it's the first with a riveted baseplate. Does this help explain the complex engineering? Was Matchbox working out how to get this right? Both Morestone and Benbros also made cars around this time with separate bases, and they're all remarkably similar to the Cresta. I've shown the inside of the Morestone A95 and the Benbros Hudson tourer because they're relatively easy to photograph, but the Morestone Beetle and Wolseley police car were also introduced in 1956.

Wild speculation now, but was the original plan to have a wide section over the axle like Morestone and Benbros? Could this be what's missing from the Cresta's back axle? Might Lesney have butchered the original master and made a second mould without the front axle brace? This isn't quite so fanciful as it sounds - the front ejector ring isn't quite in the same place on the two different bases.
Attachments
IMG_4538.jpg
Morestone A95, Benbros Hudson. Note axle braces
IMG_4538.jpg (49.36 KiB) Viewed 40 times
IMG_4540.jpg
Morestone and Benbros police car bases
IMG_4540.jpg (42.43 KiB) Viewed 40 times
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Re: 22a Bodyshell Casting Variation

Postby DrJeep » Sat Oct 14, 2017 7:20 pm

and here's part of the answer to my own question. The 22a front axle has exactly the same design as the Morestone and Benbros in my earlier post, with a wide axle brace over most of the axle. It's very difficult to photograph! It's the same on models with and without the brace on the outside, but this is the one without the outside brace.
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IMG_4545.jpg
internal front axle brace 22a
IMG_4545.jpg (35.2 KiB) Viewed 14 times
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