calculating scale to go the other way

If you want to use 3-rail track (which is 1.25 inch gauge) to represent 3 foot (36 inch) gauge, then the scale of trains would be 36 divided by 1.25 or 1:28.8 scale.  I think there were some 1:29 scale trains sold under the Aristo Craft name.

Take the track gauge, which is 1.25" and divide by 3, which gives you a measurement for one scale foot if the O 3-R track is to represent 3' gauge track.

The scale the models would be made to would be 1/24 scale, which is .416 = one scale foot.

Jeff C

Thank you Jeff , so it looks like I can fudge up to 1/2 inch .500 to the foot to build up. was hoping that was the case it makes for easier conversions. 

Do you happen to know anyone else modeling in that scale here on the forum, or links you could point me to. Thanks again.

Stan.

Lot's of scale calculators available for free on-line. I have one installed on my phone that I can grab when I'm working on the layout and want to check a dimension.

Way long ago[ late 1980s ]a very few modelers did 1/24 scale narrow gauge models on O scale track it was accurate but the rest of the hobby stayed with "G"gauge track representing a multitude of scales 

RSJB18 thats a great idea, I have started making up a book with references as a go to, seems everyday I find a new link with good info and just feel the need to save it.

Hi Dave thanks for the info. I read some place that years ago a bunch of people started in a particular scale (don't remember which one at the moment) and they built their own track and scratch built their own equipment because the only things available at the time were Japanese brass models and they at the time were expensive. I'm kind of in that same boat.  I want to do 45 mm track and big trains but the retirement budget won't allow it. So I will do what I can with what I have, and have fun along the way.

Thanks for writing back.

Stan

Interesting.

One of the old Revell models of the General was 1/24 or 1/25. I'm not sure of the gauge as is; but I think a narrow Rodgers wasn't that uncommon. Other parts might be useful too.

1/24 1/25 also makes finding the right vehicles easy as that's what scale most kits are done at. (diecast too)

Hey, Lobster Claws might even be close to scale now

Except I believe Bob is correct- the scale is closer to 1/29 not 1/24.  1/24 is 1/2" scale or .5" scale, not .416" scale. Twice as big as O scale if we use 1/48 for O scale. So if we're modeling in 1/24, the correct track gauge to represent 3' gauge is 1.5".

That said, you could put 1/24 bodies on Lionel O gauge trucks and have a fun and reasonable facsimile of narrow gauge. Who's counting? I mean it's 3 rail track and tinplate has been wildly out of scale from the get go. It sounds like a fun idea.

Good morning,

Have been busy doing Honey do's the last couple days, Installing a Mr. Kool  split air condenser unit the wife wanted in the living room.Manufactured my own heavy duty wall bracket and got it mounted on the wall and the condenser bolted in place, today is hook it up day....Yah! 

Adriatic:  Thanks for the tips not sure as I want to be modeling Lobster claws or eating them, unless you were referring to something else (R/R) that are called lobster claws and not the dip in butter critter?  

I will have to have a look see at the General, I remember that unit and name from my past but for the moment don't remember from where.

Will: So I was saying using 1/2 inch to the foot as a very rough fudge factor  keeping in the tradition of so many manufacturers who have modeled "G" into many different scales, I thought 1/24 was a good fit for me. 

Anyway I am still learning how to convert scales back and forth so how did you reverse engineer that using "O" scale 3r trucks calculates to 1.5 gauge. if used as a representation as a 3 foot rail line if you can spoon feed me the math I would greatly appreciate learning. 

I have been watching some past national Garden railroad shows from the U.K. and I love the detail in some of the modular units they have built. O-G and NG. I particularly like the variate of figures they use in and on their trains and towns. Looking forward to the day I get to that point and can detail a few places in the Garden.

Talked to my Son last night about building the raised garden bed. Someone suggested I raise the playing field  because they commented on the fact that playing trains on the ground as we get older is no fun. Yah! ....No Kidding!!!!!! I was doing some repair work to the front walk over the past weekend and boy was I hurting while down on all 4's, going to build up to at least 12"-18" in height before I lay track. Ok let me go get the A/C hooked up.

Cheer's

Stan.

Also, consider that the 1.25" 0 gauge track gauge is wrong.   That is the gauge for 17/64" scale.  Not 1/4" scale.

Our 0 gauge track should have rails a bit narrower, which is why many 0 gauge steam engine cylinders are splayed outboard.

I believe true 1/4":1' 0 scale track gauge should be closer to 1.17"

even being rough, 1/2 to the foot is way too big!     Just think if  you use .500 to represent .416 that is .09.    In terms of the original size .416 to ft, .09 is 21.6%    That means if  you build to 1/2 inch scale, your sutff will be 21.6% too large - that will look way over size.     It just won't have the proper proportions.   It will be 1/5 too large.     that is a big difference.    In my opinion, wandering more 5-7 % is about all you can do and get a good look.    .400 would be betther.

Using 7/16 to ft would be much much closer.    Taht works out to .4375 a lot closer to .416 than .500.

TomTee and prrJim

Thank you for your input and thoughts, lots to think about.

Stan

1/2" = one foot is fine with O track as long as you understand the track gauge then becomes 30" instead of 3'. 

Not really a big issue, in my opinion, but others may disagree. 

Jeff C

I agree with another poster, if you want to use O gauge equipment (2 rail or three rail) Do you really want scale fidelity (and that of course is up to you). You could likely use 1/24 equipment and it might look fine (if there is a hobby shop near you, ask them if you can see what 1/24 equipment looks like relative to the track, put a freight car or something on the track and see how the overhang looks).  I suspect for what  you want you won't notice that the track is actually scaled to 30" (a bit undersized) rather than 36". Scale O is 3.5" too wide, it is 5' instead of 4' 8 1'2", 6" too small likely wouldn't look all that bad. 

Hi bigkid, leikec.

I originally said 3 foot because all I seemed to come across in my research  was talk of 3' and 2' foot narrow gauge.

My understanding is that Ho track was used to model "O" narrow gauge.  I saw a scratch built logging flat car with a boiler mounted on it; a slap together roof structure of some kind and assorted tools hanging off the sides. I loved that look and proportion. 

Whether it represented 2' or 3' or something in between I liked the look of the exaggerated over hang of the engine and the short  little box like cars and wagons. That's the look I want!

Rather then scale the track down to Ho, I thought since Lionel trucks are so plentiful I would use Lionel trucks as a base and scale up so the cars are as proportional in look as Ho trucks are to "O" scale cars. 

Killing two birds with one stone, if I was to go with 2R rather then 3R I can still pull my Lionel rolling stock and just build a two rail engine to pull them.

Then use the same rails another time to represent narrow gauge with bigger vehicles.

So let me ask you guys this, if you start with any gauge be it N,HO, O, G and in my case Lionel 3r trucks and you want that particular gauge to represent 3 foot how do you calculate the proportions of the engine  and rolling stock to get that look i am after?

This info would be a tremendous help to me.

Stan

@Stantheman55 posted:

Hi bigkid, leikec.

 So let me ask you guys this, if you start with any gauge be it N,HO, O, G and in my case Lionel 3r trucks and you want that particular gauge to represent 3 foot how do you calculate the proportions of the engine  and rolling stock to get that look i am after?

This info would be a tremendous help to me.

Stan

Hey Stan, it's really quite easy....................

Take the track gauge you want to represent (full size measurement) and divide it by the actual track gauge you have (also full size measurement).  This will equal the scale factor.  One very important note: Both figures you start with must be in the same measurements (i.e., inches to inches, feet to feet, millimeters to millimeters, yards to yards, miles to miles, etc., etc.)

Example #1: You want to model 3' narrow gauge, using some O-gauge 3-rail track, which is 1-1/4" between the rails.  But first, we have to have "like" measurements.  So you have a choice - you can use 3' as is, and convert the 1-1/4" to feet.  Or, you can convert the 3' to inches (36"), and use the 1-1/4" as is.  That sounds easier, so let's do that.  36" divided by 1-1/4" equals 28.8, your scale factor.  1/28.8, or 1/29 scale, rounded off.

Example #2: You decide instead to model 30" narrow gauge.  You have standard O-scale 2-rail track, which is (surprise, surprise) 1-1/4" between the rails.  Since we already have inches to inches, we can go ahead and figure.  30" divided by 1-1/4" equals 24, your scale factor.  1/24 scale, or......... 1/2" = 1'-0"!

Example #3: You decide you don't have a lot of room, and might want to go quite a bit smaller, let's say using N-scale track as 3' narrow gauge.  We need to do some converting.  N-scale track is 9 mm between the rails.  Converting 9 mm to inches, we come up with .3543", just a little under 3/8".  Now we can figure.  36" divided by .3543" equals 101.6, the scale factor.  1/101.6, or 1/102 scale, rounded off.  Boy, we're gonna' have to scratch build everything if we want to stay true to that scale!  Maybe we'd be better off by arbitrarily figuring 30" between the rails instead of 36"?  Go ahead and do the math to see what scale factor we'd end up with.  Think we'd be better off going that route?  Would we be much closer to another popular scale, and not have to scratch-build everything on the layout? 

Hope this helps a little more. 

Hey Mixed freight,

Thanks so much for this excellent discussion I'm sure some body in the future will stumble across this information and the light bulb will go off answering their long held nagging questions. 

In another thread this morning we talked about 1:24 AND 1:29 both. I decided that I need to build something in 1/24 and place it on Lionel trucks to see what I get and if it's the look I am after. I think I will do the same with 1:29 and see what it looks like sitting on the trucks and on the rail. 

It will be fun to build something as part of the research and which ever car I decide to not use will make a nice model for display, or a whole other scale to model. So many options so little time...LOL

You are a wealth of hands on information thanks again.

Stan in Orlando Fl.

Hi Stan

Me and another guy, Brian Fowler, are working towards building models of EBT equipment using 1.25"-gauge track.  For the sake of convenience, we agreed to use a scale factor of 1:32 - yes, this means the actual model gauge should be 1-1/8", but we are more concerned about availability of wheels and track, while at the same time it is not difficult to source 1:32 scale vehicles and figures.  To illustrate my point about wheels, an NWSL O-scale code 172 passenger wheelset is an almost perfect match in diameter AND tread width for representing the 24"-diameter prototype wheels used on the EBT.  I'm primarily interested in O-scale standard gauge (NYC Steam-era to be precise) but building 36"-gauge prototypes to run on my existing 1.25"-gauge track will allow me to scratch that EBT itch without building a complete new layout.  I also have cast whitemetal passenger and archbar trucks for NZ Railways 42"-gauge equipment that were made to run on O-gauge track and can be used under EBT equipment until I can build more-accurate replicas.

In case anyone is wondering why we didn't go with 1:29 scale, which is more accurate for 1.25"-gauge track, this was driven by the requirement to scratch-build everything, and it is a bit easier to do the math in one's head for 1:32 scale than it is for 1:29 when calculating sizes of wood strip, styrene shapes etc.

Follow up question, If I have an HO scale building  by % do I need to make it bigger to make it O scale?

@peter allen 072518 posted:

Follow up question, If I have an HO scale building  by % do I need to make it bigger to make it O scale?

Enlarge it 181.25%.  Or rounded off, 181% close enough.

One of the reasons track gauges are wrong in our hobby was ease of converting.  Measuring in 17/64 was tough, and 1 1/4" track was easy to see on a ruler, as opposed to 1.177".

Now there is no excuse.  The simplest and cheapest hand held calculator can be programmed to spit out dimensions in any easily understood format.  Been that way for a quarter century.  And with Xerox enlargements you no longer have to do any computations - just use dividers.

I have modeled in 17/64 since 1984.  Easy to convert, even then.

I never figured out why vehicles are, for the most part, modeled in 1:43 or 1:50.

@GVDobler posted:

I never figured out why vehicles are, for the most part, modeled in 1:43 or 1:50.

I am going to take a guess it is because European "O-scale" is around 1:43 to 1:45, and some prominent makers of diecast vehicles are British and French companies. As for the 1:50 scale, it seems this applies to certain models, e.g., trucks (lorries in British slang), and it's less expensive to make them than in 1:43 scale.

Personally, I like the size of 1:43 scale cars and trucks. I have one Athearn 1:48 scale Model A Ford truck, and it is tiny looking next to the alleged 1:48 scale Lionel and MTH steamers that I own - just doesn't look "right", but maybe its because I am use to 1:43 vehicles...don't know for sure.

@bob2 posted:

One of the reasons track gauges are wrong in our hobby was ease of converting.  Measuring in 17/64 was tough, and 1 1/4" track was easy to see on a ruler, as opposed to 1.177".

Now there is no excuse.  The simplest and cheapest hand held calculator can be programmed to spit out dimensions in any easily understood format.  Been that way for a quarter century.  And with Xerox enlargements you no longer have to do any computations - just use dividers.

I have modeled in 17/64 since 1984.  Easy to convert, even then.

What's the prototype dimension across the outside of the wheel flanges, to fit in between the 4'-8 1/2" inside rail gauge dimension?

O scale narrow gauge has exactly the same question, because On3 is 19mm (= 3/4”) Gauge while On30 uses 16.5mm, HO Gauge Track. 

Both are used to model 3’ gauge prototypes, depending on where your particular “compromise point” is between scale accuracy and trade support. 

On30 is also used for the 30” gauge (760mm) common in Eastern Europe, and the larger 2’ gauge prototypes like the SR&RL prototypes 

@Stantheman55 posted:

Just a quick question about scale. How do you go about calculating scale?

What I am trying to do rather then down scale the track size as in ho track with O scale cars to make a 3 foot narrow gauge for o scale.

I want to go the other way and use standard off the shelf 3 rail track as 3 foot narrow gauge and then go the other direction and scale the size of a car to a larger size. So what would the end result scale be scale wise? I am thinking 1:22.5 in G scale roughly maybe, but not certain.

But I would like to learn how to determine scale and get an accurate measurement if for nothing else my own edification and then I would know how to fudge in scratch building.

Thanks guys.

Stan.

I often find drawings in other scales of what I want to build. I measure with a normal ruler, then I multiply the value by the scale the drawing is in.

That value gives me a real size value. I then divide that real size value by the scale I am modeling in.

i.e. Measure the length of a beam on a 1/35 scale drawing 3 inches or, 35 X 3 = 105 inches long in real life. I can then divide to my scale 105 / 55 = 1.9 inches.

Mind you, I fudge a lot because I'm lazy.

I also have a scale ruler I print out on paper. For O scale you want this:

https://www.printablerulers.ne...t_quarter-inch_scale

I also take drawings and scan them. Then I super-impose them onto my scale rule and change the scale of the drawing to match my scale if I know how long part of it is as a reference. I even get silly and cut out famous soccer goalie Gi Gi Buffon for scale and put him on there.

You can click the images below to see what I mean. The green armless dudes are 1/35 scale. My loco at that time was just an eye ball approximation and I wasn't sure what scale to work in. Then someone pointed out how those wheels would be really small in On30, but just about right in 1/55. in 1/35 I would need On30 wheels to get the right size for 2' gauge models.

With the scanned images I build cars by gluing wood right to the paper plan. It's a pretty useful cheat for scratch building wood train cars.

@Stantheman55 posted:

Hi bigkid, leikec.

I originally said 3 foot because all I seemed to come across in my research  was talk of 3' and 2' foot narrow gauge.

My understanding is that Ho track was used to model "O" narrow gauge.  I saw a scratch built logging flat car with a boiler mounted on it; a slap together roof structure of some kind and assorted tools hanging off the sides. I loved that look and proportion.

Whether it represented 2' or 3' or something in between I liked the look of the exaggerated over hang of the engine and the short  little box like cars and wagons. That's the look I want!

Rather then scale the track down to Ho, I thought since Lionel trucks are so plentiful I would use Lionel trucks as a base and scale up so the cars are as proportional in look as Ho trucks are to "O" scale cars.

Killing two birds with one stone, if I was to go with 2R rather then 3R I can still pull my Lionel rolling stock and just build a two rail engine to pull them.

Then use the same rails another time to represent narrow gauge with bigger vehicles.

So let me ask you guys this, if you start with any gauge be it N,HO, O, G and in my case Lionel 3r trucks and you want that particular gauge to represent 3 foot how do you calculate the proportions of the engine  and rolling stock to get that look i am after?

This info would be a tremendous help to me.

Stan

I see people using all those scales you talk about. Some of the more common ones:

Not sure how Z gauge measures out to N scale, but people do it. It isn't my thing as I find the blatant brush strokes on model paint to be a bit much and I do not own an air brush.

N gauge with Ho scale = HOn30

HO scale mechs can be used for 55n3, On30, 35n2, Gn15

O scale track for Narrow Gauge will achieve any scale you choose depending on your new scale.

It all really comes down to Loco Mechs. You want to choose a scale where you can find reliable mechs that resemble any locos you want to build. Your rolling stock will end up being fine since all will be scratch built to scale.

The other variables are cost, space, and sourcing details and materials. I chose my scale because I had something I could play around with that was given to me. It led to a simple loco bash, from HO scale and I had no idea where I was heading, for very little cost. Space was another issue for me, yet if you are able to do O scale you aren't as Space Challenged as me. Then again, consider how much space something G scale takes up and look at what you can do in O scale. If you ask nicely, some 3D companies will re-scale things like figures to your scale, I did that for my 55n3 figures via shapeways.

I think regardless of scale you decide on, really look at what you can source as wheels and mechs. I've seen some really beautiful 1/35 2' narrow gauge of Arizona mining lines. Lots of the details and things can be sourced by modifying 1/35 military models, so there are tons of old truck models to be used for that scale. In retrospect, I think I should have gone for 35n2. Hmmm... I guess it's never too late to scrap everything and start over.

Ok, now off to read more responses.

Hi Stan

When calculating a scale ratio, first rule is to always use the same units for the model and the prototype, be they inches, feet, millimetres or whatever.  In the case of your Lionel 3R trucks being used to represent 3-foot gauge, we know that O-gauge is 1.25 inches, and the prototype 3-foot gauge can also be described as 36 inches.  Dividing 36" prototype gauge by 1.25" model gauge, (36/1.25), gives a result of 28.8, that is, a scale ratio of 1:28.8.  That's really close to the very common garden railroad scale of 1:29, which is very handy because there is already a lot of commercially-made stuff available.  There is also scope for using 1:32 and 1:35 scale models of figures and vehicles to 'force perspective' by placing the smaller models towards the rear of the layout.  This fools the eye into thinking the models are further away than they actually are, making the layout look like it is deeper than it actually is.

Personally, I prefer the 'jewellery box' approach, whereby everything in a scene is the same scale, and the attention of the viewer is drawn away from Inconvenient Truths such as the narrowness of the layout and towards the very fine detail on the models.  There have been a few UK display layouts in the media that use matt-black backdrops, thus leaving you in no doubt as to what you are supposed to focus your attention on!

Regards

Paul