56a London Trolleybus - unlisted variations

[Diecast]

There are two unlisted variations, the first is the wheels variation, the second one is the casting variation.
There are two types of the metal wheels:
a) "56" MW ø7,5x18
b) "no name" MW ø7,5x18 (on all axles)
Antonin

[Diecast]

There are known two casting variation on the inside of the roof, with smooth and cross hatching surface. I have three variations in my collection:
a) smooth roof interior

[Diecast]

b) crosshatched roof interior

[Diecast]

c) coarse or multiple crosshatched roof interior (similar to 20c Chevrolet Impala Taxi)

[Idris]

I think (b) and (c) are most likely to represent twin tools.

[Diecast]

My proposal of the new lis 56a London Trolleybus. Please comment
Antonin

[matchboxkiwi]

What was the idea with that cross hatched roof pattern?
Was it to strengthen it or just to collect the dust?

Cheers, Steve
Matchboxkiwi

[Idris]

What was the idea with that cross hatched roof pattern?
Was it to strengthen it or just to collect the dust?

As I understand it, there is some kind of issue with releasing large smooth areas of casting from the tooling. The cross-hatching breaks up the inner surface of the roof, so improving casting release.

[GHOSTHUNTER]

...yes, as stated above by "Idris".

The 'Cross-Hatching is not unique to Lesney, it can be found on other brands of toy and model cars. It prevents 'Capillary Action' from working, holding the castings in the cavities of the tools (moulds) when what you want is the castings to come out of the tools!

In some cases the 'Cross-Hatching' can not be added to the surface, especially if the surface is meant to be smooth, so the answer is to design something like trim lines or an additional little detail like a door hatch, to just break up the area to work in the same way as if there was some 'Cross-Hatching' put there. The most well known example of this was on a 'Yesteryear' model's roof, which from Day One of production in late 1968, was totally smooth but during 1970, a series of dead straight well defined lines appeared towards the rear section of the roof, something the real car does not have!

GHOSTHUNTER.

[Idris]

The 'Cross-Hatching...prevents 'Capillary Action' from working, holding the castings in the cavities of the tools (moulds) when what you want is the castings to come out of the tools!

No it doesn't. Capillary action is a property of liquids, not of solids. My guess is that the cross-hatching somehow makes it easier to part the two solid surfaces, perhaps by allowing easier air ingress.