HO scale weight?

[Selector]

I may have misunderstood, but I thought the whole point was to determine what the model 'should' weigh, if it was a perfectly scaled version in all respects. In which case, it doesn't matter what materials the model is made of, it 'should' weigh the original weight /87.1^3 (for HO scale).

If the model is crafted from balsa wood, a material many times less dense than homogenous carbon steel, it will be many times lighter than a comparable model made of the steel. So, the materials do matter...a lot.

 

[cv_acr]

Oh for crying out loud...

You are way over complicating this Selector.

The question was what the "scale" weight of a prototype engine should be. Take the published weight of the real thing, divide it by 87^3. Boom, you're done. That's the prototype weight, scaled down.

Obviously if you build your model out of marshmallows and duck down it's not going to be remotely close to the scaled prototype weight. If you're trying to add weight to your model to match a desired target (either the scaled down prototype weight, or the handy NMRA recomended weight formula of 1oz + 1/2oz per inch of length, or your own standard) a handy tool called a "scale" will tell you if you're getting close without the need for all sorts of material density calculations.

I don't know why you're trying to complicate this discussion so much.

 

[NH Mike]

As long as we are neck deep in the discussion I want to toss this out there. If a prototype helium tank car weighs 42,000 lbs empty and then it is filled with helium, will it weigh more or less when run over a scale? I need to know this so when I build my old Ambroid US Navy helium tank car kit I can weight it correctly.

( this message sent from the Twilight Zone )

 

[cv_acr]

Well the gas would be compressed, so even though the individual molecules are very light, the density is increased. The car would be heavier loaded than empty, but I don't know what a loaded helium car would weigh. There should be capy/load limit stencils on the car that will give you the max. Weight capacity of the loading.

 

[Selector]

Oh for crying out loud...

You are way over complicating this Selector.

The question was what the "scale" weight of a prototype engine should be. Take the published weight of the real thing, divide it by 87^3. Boom, you're done. That's the prototype weight, scaled down.

Obviously if you build your model out of marshmallows and duck down it's not going to be remotely close to the scaled prototype weight. If you're trying to add weight to your model to match a desired target (either the scaled down prototype weight, or the handy NMRA recomended weight formula of 1oz + 1/2oz per inch of length, or your own standard) a handy tool called a "scale" will tell you if you're getting close without the need for all sorts of material density calculations.

I don't know why you're trying to complicate this discussion so much.

Cool yer jets, Chris. I was addressing the second statement in FCL2117's post just above mine. The materials matter...period.

 

[LoudMusic]

Well the gas would be compressed, so even though the individual molecules are very light, the density is increased. The car would be heavier loaded than empty, but I don't know what a loaded helium car would weigh. There should be capy/load limit stencils on the car that will give you the max. Weight capacity of the loading.

What if instead of compressing air INTO it, you decompress air OUT of it?

Oh that's right, it implodes!

But does it weigh less?