Things which are impossible to model

[Sandpiper]

A real lineside fire caused by a passing steam loco could be quite interesting if someone with a suitable layout fancies trying it. Probably something with a large scenic area would be best. 

[Talltim]

A real lineside fire caused by a passing steam loco could be quite interesting if someone with a suitable layout fancies trying it. Probably something with a large scenic area would be best.

And scale working fire engines..

Edited June 18, 2018 by Talltim

[Skinnylinny]

And scale working fire engines..

The Germans have been working on that...

 

https://www.youtube.com/watch?v=IvrroMSyKzQ

 

The video has German "voice acting" but can be set to show English subtitles.

[Sandpiper]

And scale working fire engines..

 

Along with a full size one waiting outside just in case things got a little out of hand.

[jjb1970]

Apparently the last frontier model making is the quest to build a decent class 50. Companies choose to try to make a class 50 not because it is easy but because it is impossible etc etc  

[The Johnster]

To be fair, English Electric only ever managed it once, with DP2...

 

That one was the best looking as well!

[John_Miles]

There are things in 4mm scale which cannot be accurately reproduced, for instance scale thickness footplates would be around 0.1 mm or about 3 thou. Much too flimsy.

[jcm@gwr]

There are things in 4mm scale which cannot be accurately reproduced, for instance scale thickness footplates would be around 0.1 mm or about 3 thou. Much too flimsy.

 

Signal arms being another example!

[PaulRhB]

Much of what is 'impossible' isn't really, scale thickness etc. If we didn't insist on handling with giant hands and causing G forces that a F1 driver would struggle with round corners

Also wind doesn't scale very well so signal arms have to survive the odd micro hurricane as we sneeze!

Until we scale all the environmental factors we have to re-engineer slightly to withstand them. There's a chap that can model figures as small as a human hair so that takes us down to scale modelling of model figures on model railways and possibly figures on those models!

Much is only difficult due to the cost of engineering it being a tad prohibitive for most of us, and then we wouldn't be able to touch without damaging it!

[justin1985]

I think back projection of weather effects etc onto fabric backscenes could be a viable goer, BUT the problem, as with using LED monitor screens etc is that they're all light SOURCES - it would surely be odd to have a layout backlit like that if that includes light coming from backscene features other than the sky. Perhaps if the sky was back projected but the horizon was a solid silhouette in front, that might work?

 

Potentially easier might be straightforward projection of moving cloud, weather, etc onto a plain backscene from a lighting gantry. Presumably the people who do commercial projections onto buildings etc have ways of configuring and adjusting the image to account for the shape of the object they're projecting onto?

 

Justin

[PaulRhB]

But all we see is light reflected so effectively even buildings 'give off' some light

As long as the front lights correct the balance it will work ok. It will actually counter some of the strong shadows on layouts that only have a front light source

Edited June 23, 2018 by PaulRhB

[Pacific231G]

Much of what is 'impossible' isn't really, scale thickness etc. If we didn't insist on handling with giant hands and causing G forces that a F1 driver would struggle with round corners

Also wind doesn't scale very well so signal arms have to survive the odd micro hurricane as we sneeze!

Until we scale all the environmental factors we have to re-engineer slightly to withstand them. There's a chap that can model figures as small as a human hair so that takes us down to scale modelling of model figures on model railways and possibly figures on those models!

Much is only difficult due to the cost of engineering it being a tad prohibitive for most of us, and then we wouldn't be able to touch without damaging it!

Unfortunately, for anything involving movement and forces, there's more to scaling than just reducing every dimension linearly. Some variables are linear but others are square or cube functions. It's also difficult to scale time, so movements will tend to be very jerky in a model especially in the smaller scales. There are ways of reproducng movement, for example getting semaphore signal arms to bounce convincingly, but they require artifice. 

 

We can be grateful for this- it's  why spiders the size of elephants or birds the size of horses only exist in horror movies. 

Edited June 24, 2018 by Pacific231G

[John_Miles]

Unfortunately, for anything involving movement and forces, there's more to scaling than just reducing every dimension linearly. Some variables are linear but others are square or cube functions. It's also difficult to scale time, so movements will tend to be very jerky in a model especially in the smaller scales. There are ways of reproducng movement, for example getting semaphore signal arms to bounce convincingly, but they require artifice. 

 

We can be grateful for this- it's  why spiders the size of elephants or birds the size of horses only exist in horror movies. 

 

This is why things like momentum cannot be reproduced. Imagine a model train taking the same distance as the prototype to stop. It would be well of the end of most model railways if travelling at speed and when crashes occur on models, happily they don't destroy the PWay and other objects.

[Norm81]

I've yet to see a dog peeing up a lamppost modelled, with liquid flowing and the appropriate aroma

[RobClogs]

The trick with the passengers disappearing from the bench when the train is hiding them has been executed by the builders of B.A. Bodil, a multi-scale diorama. 
Here's a video. The chap waiting for the train at 2:40 has disappeared when the train leaves again. And there's more movement.

Edited June 25, 2018 by RobClogs

[dolydd]

I've yet to see a dog peeing up a lamppost modelled, with liquid flowing and the appropriate aroma

Why on earth would you want to model that anyway!?

[PaulRhB]

This is why things like momentum cannot be reproduced. Imagine a model train taking the same distance as the prototype to stop. It would be well of the end of most model railways if travelling at speed and when crashes occur on models, happily they don't destroy the PWay and other objects.

Momentum is already widely reproduced, ok its compressed like our layouts but it's there.

Funnily enough reproducing momentum using dcc programming lead to this when he didn't take it into account!

So momentum and destruction of my pway!!!!!

And the guilty party is a fellow railwayman