# A3 switcher in g



## cjsrch (May 29, 2010)

I am planning on building the pennsy a3 switcher in g gauge. Currently I am planning on dividing all messuments and thicknesses in half except the boiler thickness. This also includes screws and sheet metal. Does anyone see an issue with that. Has anyone done it


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## David Leech (Dec 9, 2008)

Sorry, not sure what you mean. 
Dividing in half from what? 
All the best, 
David Leech, Delta, Canada


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## Scottychaos (Jan 2, 2008)

I assume he is probably talking about "dividing in half" from the Kozo Hiraoka plans,
well known in the larger scales..but not well known in "small scale" live steam.


Kozo Book 

(not sure what scale that is usually built to..1/12 scale perhaps.)


but yes, some clarity is needed in the original post! 
Scot


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## Scottychaos (Jan 2, 2008)

Posted By cjsrch on 13 Jan 2011 06:40 PM 
I am planning on building the pennsy a3 switcher in g gauge. Currently I am planning on dividing all messuments and thicknesses in half except the boiler thickness. This also includes screws and sheet metal. Does anyone see an issue with that. Has anyone done it 





You cant divide *everything* exactly in half, because you have to adjust the gauge so it will run on 45mm track..
assuming the original plans are 1/12 scale, dividing in half gives you a 1/24 scale model..
this would work fine, except for the gauge..

a true 1/24 scale standard gauge locomotive would have a track gauge of 60mm.

you will have to adjust this down to 45mm if you want it run on "G gauge" track..

but apart from making adjustments for the gauge, (which might or might not be a problem) I see no other issues with building a "half size" Kozo 0-4-0..
it will be big! compared to other standard gauge trains in 1/29 and 1/32 scales..

you could always go all the way and just build it to 1/32 scale! 
then you dont have to adjust the gauge..
it would be smaller than the 1/24 version, but not too small, and you would also have the satisfaction of the whole thing being to the correct scale.

and you could also then get matching 1/32 scale standard gauge freight cars to go with it..(there are beautiful cars being made in 1/32 scale) 

there are no standard gauge 1/24 scale cars.. 


(moving in the drivers on the 1/24 scale version could cause issues..because the frame, drivers and cylinders need to be narrower compared to the rest of the engine..
building it in 1/32 scale could be much easier in this respect..) 


Personally I would adjust the plans to 1/32 scale..seems better all around. 


Scot


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## Slipped Eccentric (Jan 2, 2008)

You cant divide *everything* exactly in half, because you have to adjust the gauge so it will run on 45mm track..
assuming the original plans are 1/12 scale, dividing in half gives you a 1/24 scale model..
this would work fine, except for the gauge..

a true 1/24 scale standard gauge locomotive would have a track gauge of 60mm.

you will have to adjust this down to 45mm if you want it run on "G gauge" track..

but apart from making adjustments for the gauge, (which might or might not be a problem) I see no other issues with building a "half size" Kozo 0-4-0..
it will be big! compared to other standard gauge trains in 1/29 and 1/32 scales..

you could always go all the way and just build it to 1/32 scale! 
then you dont have to adjust the gauge..
it would be smaller than the 1/24 version, but not too small, and you would also have the satisfaction of the whole thing being to the correct scale.


(moving in the drivers on the 1/24 scale version could cause issues..because the frame, drivers and cylinders need to be narrower compared to the rest of the engine..
building it in 1/32 scale could be much easier in this respect..) 


Scot 


Kozo's plans were run in the 90's in Live Steam magazine, drawn in 1/16 scale for 3.5" gauge track.
I started building a half size models years ago, but was going to build a single flue gas fired boiler. I think that he designed it to use .080" thick copper, but I wouldn't use less than 1/16" thick in the half scale model.


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## tacfoley (Jan 3, 2008)

Posted By Scottychaos on 13 Jan 2011 09:16 PM 
Posted By cjsrch on 13 Jan 2011 06:40 PM 
I am planning on building the pennsy a3 switcher in g gauge. Currently I am planning on dividing all messuments and thicknesses in half except the boiler thickness. This also includes screws and sheet metal. Does anyone see an issue with that. Has anyone done it 





You cant divide *everything* exactly in half, because you have to adjust the gauge so it will run on 45mm track..
assuming the original plans are 1/12 scale, dividing in half gives you a 1/24 scale model..
this would work fine, except for the gauge..

a true 1/24 scale standard gauge locomotive would have a track gauge of 60mm.

you will have to adjust this down to 45mm if you want it run on "G gauge" track..

but apart from making adjustments for the gauge, (which might or might not be a problem) I see no other issues with building a "half size" Kozo 0-4-0..
it will be big! compared to other standard gauge trains in 1/29 and 1/32 scales..

you could always go all the way and just build it to 1/32 scale! 
then you dont have to adjust the gauge..
it would be smaller than the 1/24 version, but not too small, and you would also have the satisfaction of the whole thing being to the correct scale.

and you could also then get matching 1/32 scale standard gauge freight cars to go with it..(there are beautiful cars being made in 1/32 scale) 

there are no standard gauge 1/24 scale cars.. 


(moving in the drivers on the 1/24 scale version could cause issues..because the frame, drivers and cylinders need to be narrower compared to the rest of the engine..
building it in 1/32 scale could be much easier in this respect..) 


Personally I would adjust the plans to 1/32 scale..seems better all around. 


Scot 







+1.

45mm track gauge = Gauge 1. Many components are readily available in this scale - all boiler fittings, wheels, couplers et al. 

tac
http://www.ovgrs.org/
Supporter of the Cape Meares Lighthouse Restoration Fund
G1MRA #3641


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## cjsrch (May 29, 2010)

actualy the kozo a3 is for 3.5 inch gauge so half works out to 1.75 or just shy of 45 mm being at 44.45 or so kozos book is for a 3/4 scale engine (1/16) 
so by dividing by 2 i am getting a 1/32 engine  you all scared me for a second. 

As far as what i was asking i was typing from an iphone and most of my attention was on typing rather then on asking a question. but basicaly what should i be dividing in half EVERYTHING even the thickness of the material and the width of the screws or just the external dimensions. the kozo books call for a lot of platemetal work.


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## tacfoley (Jan 3, 2008)

Sir - respectfully, a boiler made to half the size of an original design does not behave like a half-sized boiler, regardless of the means of heating it. You would do well to listen to the advice of folks on this site with real experience of miniature boiler-making - depending on how you want to boil the water - by gas, coal or alcohol firing. In Canada, there is the redoubtable Dick Abbott - hopefully the south-of-the-border mavens will kick in here, too.

Incidentally, Kozo-san's designs are intended to take into account the marked lack of cast components available in Japan, hence the emphasis on fabricated parts wherever feasible. His Shay designs have very few castings in them if any - my copy of the book has long disappeared so I'm unable to check my failing memory. 
Lots of luck!

tac
http://www.ovgrs.org/


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## SteveC (Jan 2, 2008)

To me, the simple answer to your question would be no, you can't just divide everything in half and have it work out.

For the over-all external dimensions (length, width, & height) reducing by half should in most cases work out, but even there you may very well run into cases where adjustments will need to be made.

For example, if you take the actual thickness of the material that Kozo uses to make side frames out of and then scale it up to the prototype, I doubt that the measurements would match what was used in the prototype. That's because the structural properties of a given material don't change with scale. They remain pretty much the same, so what is structurally sound in one size may not remain so at a larger or smaller size. Thus, on one hand the item could wind up being way over-built and on the other hand structurally unsound for the task it's being asked to do.

The other problem that I believe you'll encounter, is that you'll have to use material that is available for purchase. And in most cases the gage (thickness) of the metal available won't match exactly what you're looking for, so you'll need to use something either thinner or thicker. Which in turn will change some of the dimensions of many of the items, and may also affect the method of fabrication used by Kozo and you'll have to once again adjust to accomplish the task.

All of the above will also hold true with the sizing of the fasteners used too.

You could divide various things in half as a rule-of-thumb to see what is available and how close of a match you can make, and then check that the method of fabrication called for will still be viable, the structural soundness remains intact, etc. etc.


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## afinegan (Jan 2, 2008)

Hey chris,


My kozo A3 switcher book(I already have "building the new shay") is in the mail to me and I was thinking of this exact project as my first loco also. I guess it would work as long as you compare things to the gauge 1 trains we already own.


I would divide everything by 1/2 (or whatever makes the gauge proper to 45mm, not exactly 1/2) then check an existing locomotive (or one of mine at a meet) and see if the materials are similar(not smaller, slightly larger is ok) in thickness. I think this is a safe way of building the locomotive. I know the steam dynamics can't be scaled perfectly, but I bet that modifying the loco's items a little bit (using a working gauge 1 loco to compare/contrast material sizes and fittings) would work.


Expect to remake/modifying parts if they don't work


Experts: chime in if you feel this is a good way of building it since I am no expect in locomotive fabrication (but hopefully will be in the near future).


Andrew


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## rwjenkins (Jan 2, 2008)

Ed Hume built the Kozo Climax scaled down to 1:20.3 (and converted to narrow gauge) a couple years ago, so in theory, yes the Kozo designs can be re-scaled. Here's a link to a thread here on MLS about it: http://www.mylargescale.com/Communi...fault.aspx

The Kozo A3 book also contains information about doing the opposite, doubling the size up to 1 1/2" scale to run on 7 1/4" or 7 1/2" gauge. Mostly that involves the addition of working brakes, adjusting for the difference in track gauge, and changes to the boiler design, but it might at least give you some ideas about things to think about when building the engine to a different scale.


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## Charles (Jan 2, 2008)

Scaling the plans down are doable...combine with enough working productions that one could reference "gauge 1" materials for thickness relative to frame, valve gear, boiler jacket, cab, tender shell, trucks, etc. Then you can either make cylinders or purchase from manufacturer. Other things like screws, bolts, wire, can be found in most supply companies.
Please post your experiences!


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## cjsrch (May 29, 2010)

ok so ill take some messurments today if i can and then get started on this thing


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