Scale

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hoppercar
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Scale

Post by hoppercar » Sat Jun 06, 2020 9:49 am

Well we all understand 1 1/2 inch scale....its 1/8th full size.........but recently I have been seeing posts. For 1:22.58 scale....???....I dont get that at all ?....what is this ???

Moron
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Re: Scale

Post by Moron » Sat Jun 06, 2020 10:49 am

I might be wrong in this and I don’t know the exacts, but basically it’s full size 2 foot or 18inch mining gauge (or something similar) to run on G gauge track. At least that’s what I’m getting from it

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Fender
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Re: Scale

Post by Fender » Sat Jun 06, 2020 10:53 am

G-gauge track (aka #1 gauge) is a popular size for models now, and is 1.75 inches between the rails. Many narrow-gauge railroads overseas were built to meter gauge, or 39.37 inches between the rails. So models of meter gauge engines running on G-gauge track are built to a scale of 1.75 : 39.37, equivalent to 1 : 22.50
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AnthonyDuarte
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Re: Scale

Post by AnthonyDuarte » Sat Jun 06, 2020 11:38 am

1/8th full size is another way of expressing a scale ratio of 1:8.

1:22.58 would closely represent standard gauge on 2.5" gauge track.

To determine inches-to-the-foot from a scale ratio, you just need to divide 12 by the ratio. 12/22.58 = .5314 (12/8=1.5 for 1/8 scale)

2.5" gauge track divided by .5314" inches to the foot (2.5/.5314) = 4.7045 represented feet, which is very nearly 4' 8.5".

Scale is not inextricably linked to gauge, so you could theoretically take this ratio and apply it to different existing track gauges to see what it works out to be. In gauge 1 (45mm), 1:22.58 would make the track represent 3.3327 feet, or 40" gauge. It's very close to meter gauge, however 1:22.2 is much closer for that. In 3.5" gauge it represents 6.58 foot gauge, so that's not too likely.

Hope this helps.

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ccvstmr
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Re: Scale

Post by ccvstmr » Sat Jun 06, 2020 11:44 am

Hoppercar...in the garden railroading part of the hobby, there are actually several scale factors out there. They are all closely related. Depends on which train manufacturer you were dealing with. Generally speaking...trains in that scale "range" are for the "G-gauge" train stuff. Carl B.
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Fender
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Re: Scale

Post by Fender » Sat Jun 06, 2020 12:41 pm

I'm sure the O.P.'s question deals with the current topic "Decauville 0-4-0.." which is stated to be 2.5" gauge. So I think Anthony's explanation is correct. More commonly 2.5" gauge is associated with one-half inch scale, or 1:24 ratio, but calculating the scale and gauge more exactly, it is 1:22.58, analogous to 7.5 inch gauge guys using 1.6 inch scale to more accurately match the model with the track gauge. The oddball ratio is because the 2.5" track gauge doesn't exactly match half-inch scale.
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AnthonyDuarte
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Re: Scale

Post by AnthonyDuarte » Sat Jun 06, 2020 1:46 pm

It just occurred to me you can more simply multiply the track gauge by the scale ratio. 2.5" gauge track times 22.58 = 56.45" (56.5" is standard gauge)

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LVRR2095
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Re: Scale

Post by LVRR2095 » Sat Jun 06, 2020 3:08 pm

Fender wrote:
Sat Jun 06, 2020 12:41 pm
The oddball ratio is because the 2.5" track gauge doesn't exactly match half-inch scale.
2.5” gauge for 1/2” scale is more of a British thing. Here in the U.S. designers such as H.J. Coventry designed their locomotives to 17/32” = 1’ scale on 2.5” gauge track.

Keith

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Fender
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Re: Scale

Post by Fender » Sat Jun 06, 2020 4:41 pm

LVRR2095 wrote:
Sat Jun 06, 2020 3:08 pm
Fender wrote:
Sat Jun 06, 2020 12:41 pm
The oddball ratio is because the 2.5" track gauge doesn't exactly match half-inch scale.
2.5” gauge for 1/2” scale is more of a British thing. Here in the U.S. designers such as H.J. Coventry designed their locomotives to 17/32” = 1’ scale on 2.5” gauge track.

Keith
Interesting. If you divide 17/32 into 12 inches, you get exactly 22.5882353; maybe that’s where this comes from!
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baggo
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Re: Scale

Post by baggo » Sat Jun 06, 2020 5:53 pm

It's true that 1/2" to 1' was originally used in the UK for 2.5" gauge but it has been 17/32" to 1' since the 1920's. All the early 2.5" gauge designs by Henry Greenly and sold by Bonds of Euston Road, although advertised as 1/2" scale, are actually 17/32" to 1' and clearly marked as such on the drawings.

H J Coventry's 'President Washington' is actually 1/2" to 1' as is the Miller Hudson.

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LVRR2095
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Re: Scale

Post by LVRR2095 » Sat Jun 06, 2020 5:57 pm

The Coventry P-7 irrespective of what that article states is 17/32” to the foot.
They called it 1/2” scale as that is what most people called it.
Last edited by LVRR2095 on Sat Jun 06, 2020 7:19 pm, edited 1 time in total.

jcbrock
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Re: Scale

Post by jcbrock » Sat Jun 06, 2020 7:18 pm

There's gonna be arithmetic?
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