I think it's all to one scale (1:48), but some UK liveried items are actually continental prototypes and may appear to be overscale compared with the coaches.
I think the Lima were a hybrid scale, something like 1:45.
Those are 1/48, being intended for the US market.
It's a bit of a mix and match though, because the prototype was
3' gauge instead of 2'6". Although the little Porter was available for a variety of inductrial gauges including 2'6". But eg the the Colorado stuff was 3'.
That's dependent on what degree of compromise you're prepared to accept in scaling your models. I don't see any point in converting a metric prototype dimension to an Imperial measurement and then dividing by an Imperial:Metric ratio to get a metric model dimension which fractionally doesn't match the accepted and official metric scale. Once I know the scale dimensions I wish to model, I make the adjustments to suit the materials and tools available and to suit my modelling skills. I certainly wouldn't use the US rounded scaling factor, because that introduces an error before I make my own modelling compromises.
So your models of 1m diameter wheels will measure 11.4942528736--- mm or do you use something other than exact scale? Perhaps an 11.5mm wheel, ie scale of 1:86.96, or even an 11mm wheel, a scale of 1:90.96 (and I know they might be worn wheels, that's not the point)
The difference between 1:87 and 1:87.1 is not significant in modelling, even P87 track and wheels are compatible whichever scale you use. An 80ft car is 0.28mm different in length, can you model well enough to tell? Keith
Make friends in the hobby. Visit Garratt photos for the big steam lovers.
Hmmm, my wheels measure 11.5mm, 11.08mm and 10.5mm depending on the situation.
Yes there is a significant difference: - I start with a prototypical dimension - I apply my scale factor - I _then_ adjust to suit any factors I decide are appropriate.
You say the ".1" is not significant. That immediately brings forth two questions:
- why include it?
- when does a figure become significant?
-1:76(.2)?
-HO by MOROP standards is 1:87 with 1:80 as an alternative. I'm informed by some modellers that the difference isn't significant! That extra figure can affect rounding of a converted dimension when one works to the nearest 0.5mm. When I fit my wheels to, for example, a Roco wagon I have to take into account that Roco have already fudged the design to suit 11mm wheels, Märklin to suit
10.5mm wheels. Correct diameter 11.5mm wheels won't fit without fudging other dimensions.
A length over buffer beam and a length over buffers rounding can make a difference that is visible in a model.
So where do they get 1:43.5 and 23mm/m from then? Both of those are
7mm/ft rounded off as you so like to do but indistinguishable in practice except to those who can see the effect of 0.28mm in a 280mm long coach. 1:45 is the 'corrected' scale to correctly fit 32mm gauge. So, IMHO, there are two european 'O' scales and several ways of expressing them. Keith
Make friends in the hobby. Visit Garratt photos for the big steam lovers.
They come from dividing the prototype gauge by the model gauge - why would Europeans use English feet when converting a prototype metric measurement to a model metric measurement? I fell foul of this situation years ago in converting Württemberg prototype drawings in "fuss" (feet) to scale size using 3.5mm as the conversion factor. They are a quite different measurement!
Yes, there are at least two European continent 'O' scales and considerable arguement as to which is "correct".
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.