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Any S-Scale Question Answered


Lacathedrale
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8 hours ago, Lacathedrale said:

Absolutely beautiful. You'd recommend then that the bogie has individually sprung hornblocks rather than pivoting frames? As I said this is literally the first time I'm attempting this so success is more important than it being perfect!  At this stage, if someone can say 'do it this way, it'll work and be the most expedient way to achieve it' then I would very much appreciate that, and then once I have one under my belt, can experiment with alternate solutions :)

 

I'm not in a position to say if individually sprung hornblocks are any better than a pivoting frame or even equalising beams for that matter. The only experience I have of building a 4-4-0/0-4-4 chassis is what I posted above. I expect any of the methods mentioned will do the job and the decision to adopt one particular method will come down to the indivduals prefrence.

 

Before starting the NBR 4-4-0T I did consider the method described on the CLAG website but felt it was a bit over engineered. I opted for the Exactoscale sprung hormblocks as I felt it was fairly simple to set-up and I liked the idea of soldering the hornblocks to the outside of the frames to represent the external axleboxes.

 

Scott

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OK, so for the sake of argument if my bogie and my driving wheels are both using twin compensating beams - what's the simplest way to lay that out? Is there a standard implementation guide I can see? I do apologise for asking as I get the impression that this is very much 'salt to taste' but I just don't have a reference point from which to diverge.

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A rough sketch hopefully explains the idea: the details are up to you. The beams can rest on the tops of the axleboxes, or indeed contain the bearings, particularly for the bogie.

Open circles are bearings, solid circles are pivot points. The red triangle is purely illustrative of the three-points of the suspension. Purple arrows show movement.

 

C6E0BCBD-0278-4AA9-BA41-D4269CF7DD9E.jpeg.7a96863e81484cf6a5d9fe8695254cc4.jpeg

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On 27/12/2020 at 13:38, ScottW said:

I have two unfinished chassis' on my shelf waiting to be finished, both of which I am ashamed to say were started a long time ago. One is for an NBR 4-4-0T and the other a CR 0-4-4T.

At the risk of being a pot calling the kettle black, how are those progressing?

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2 hours ago, Lacathedrale said:

OK, so for the sake of argument if my bogie and my driving wheels are both using twin compensating beams - what's the simplest way to lay that out? Is there a standard implementation guide I can see? I do apologise for asking as I get the impression that this is very much 'salt to taste' but I just don't have a reference point from which to diverge.

 

As far as I am aware there is no 'one size fits all' method. Using the theory behind each of the various concepts I believe people tackle the practicalites based on their own ideas and abilities. After all, what works for one person might not necessary work for another. It might be worth posting the question in the Kitbuilding & Scratchbuilding section to gather ideas on how other people have tackled compensating/springing a 4-4-0/0-4-4 chassis?

 

Scott

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2 hours ago, Regularity said:

At the risk of being a pot calling the kettle black, how are those progressing?

 

They're not!!!

 

Over the years I have been getting distracted by other projects. That said, I am having thoughts on continuing again with the Caley 4-4-0T, I just wanted to get a few wagon projects out the way first. Also, I'm keeping my ear to the ground waiting to see what @flubrush does, he had made a few noises that he might produce some prototype wheels for the Caley 439 class. :whistle:

 

Scott

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2 hours ago, ScottW said:

 

Also, I'm keeping my ear to the ground waiting to see what @flubrush does, he had made a few noises that he might produce some prototype wheels for the Caley 439 class. :whistle:

 Not at the moment - my CNC mill is out of service.    It was old enough to rely on using the old 25pin parallel port on a PC for its connection and the old PC driving it gave up the ghost a week ago.  So rather than try and find another old PC with a parallel port,  I am biting the bullet and upgrading the machine to work from the USB port of an up-to-date PC.  Wish me luck. :-)

 

Jim.

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3 hours ago, ScottW said:

 

After all, what works for one person might not necessary work for another. It might be worth posting the question in the Kitbuilding & Scratchbuilding section to gather ideas on how other people have tackled compensating/springing a 4-4-0/0-4-4 chassis?

 

 

I'll just tag this on here.   I am reminded of Stan Garlick's method of compensation onj an 0-4-2 tank,  which was the same as Simon has oulined above.  But in Stan's case he made the frames as a sandwich of thin plate spaced apart and the equalising beams on the driving wheel axles were hidden in the sandwich.   It was a bit of extra work,  but probably worth it if your locomotive had a lot of space under the boiler and equalising beams on the inside of the frames would be quite noticeable.    If I remember correctly,  the locomotive and its compensation featured in an article in the MRN or MRC in the early 1960s.

 

Jim.

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Depends on how short, and how tight your curves are.

 

For coaches, I would suggest the SSMRS etched fret produced for us by Brassmasters.

 

For my short wheelbase (11' total) 6-wheel brakevan, I simply used standard wagon w-irons for the outer axles, dummy w-irons (same source) for the middle axle, and a piece of 2mm inside diameter tube, cut to fit between the inside wheel faces, fixed to a piece of springy steel wire (about 0.011" - electric guitar top E string) to keep it on the rails, but otherwise transfer virtually no weight to the axle. 

I made that up on a trial and error basis.

 

As with everything, you can do it however suits you, but if there is something available, why not patronise the SSMRS parts department?

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Hi all, I wasn't sure whether to ask this here or start a new thread, but this seemed like the best option.  What sort of radii are typical in S? 

 

I'm considering the scale for a shelf layout where it isn't too much of an issue but eventually want to have balloon loops at which point it would become important.  I've tried searching for information myself but all I've been able to find is figures from the US which seem implausibly tight. 

 

In terms of what I'll be running, Jubilee 4-6-0s would be the largest regulars but the occasional big Pacific on a funny train would be nice.

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48 minutes ago, Coder Tim said:

Hi all, I wasn't sure whether to ask this here or start a new thread, but this seemed like the best option.  What sort of radii are typical in S? 

 

I'm considering the scale for a shelf layout where it isn't too much of an issue but eventually want to have balloon loops at which point it would become important.  I've tried searching for information myself but all I've been able to find is figures from the US which seem implausibly tight. 

 

In terms of what I'll be running, Jubilee 4-6-0s would be the largest regulars but the occasional big Pacific on a funny train would be nice.

 

The minimum radius recommended is normally around 48 inches and you might want to add in a bit of gauge widening as well.  That would normally allow for smaller locomotives - 0-6-0 tender,  0-6-0 tank, etc.     You can go tighter than that but you are then limiting yourself to short wheelbase locomotives - like 0-4-0 tanks - and gauge widening would be necessary.  Jas Millham does get larger locomotives round less than 48 inch curves but he does clever things with their chassis to achieve that.   For Jubilees and large Pacifics,  I suspect that you are going to have to look at larger than 48 inch radius curves - maybe 60 inch and larger.  Their longer driving wheelbase and accommodating clearance for bogies, etc.,  would probably require that.

 

Another thing that can help with tight radii is using wheels with deeper flanges and some 4mm scale wheel profiles would suit,  also some of the Gibson S scale products as well.

 

Jim.

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Stephen Rabone made a Patriot go round 36” radius curves. http://steverabone.com/sscalewebsite/indexpage.htm

 

It’s perfectly possible to get virtually anything round curves this tight, but you may have to make some interesting decisions: flangeless centre drivers; extra side-play, coarser wheel and track standards, which latter ruins any chance of running elsewhere. Let me be clear: no one is forced to use the SSMRS standards, but standards are the only way to ensure interchangeable running, and we only have a single set at the moment.

 

Prototype locos could usually creep around a 4 ½ chain radius curve, but there was usually some gauge widening - again, part of the SSMRS standards. Scaling factors on forces, etc, mean that whilst model railways are subject to the same mathematical rules which describe the behaviour of the prototype, the outcome can be different, and such a curve could be traversed at greater scale speeds on a layout - plus there are no lives exposed to danger. A chain is 66 feet, near enough to 12” when scaled down as an approximation for S, so 4 ½ feet would look and run ok. 
 

For the shortest possible balloon loop without transition curves, though, that’s 13 ½ feet of layout length (plus clearance at the end). Layouts have been built which are shorter than that!

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Brilliant, thanks both.  That's actually better than I expected.  I've wondered about deeper flanges before but much prefer the scale ones.  I think for this first layout I'll go with the ssmrs standard and see if I have any trouble making track well enough for reliable running.  Thanks again!

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As mentioned above I have managed to build a series of "big" locos that will go round my ridiculously tight 36" radius curves on one of my layouts (and if I chose at even more ridiculous speeds without derailing!) . Point radii are at least 48" on my British layout. These are all LMS locos - the Class 5 and Patriot and Jubilee 4-6-0s (the latter is just about to enter the paint shop) as well as several 2-6-4Ts and a Stanier 2-8-0. I've used a mixture of wheels - some Gibson and some Markits with axles as made for the SSMRS. None of the chassis needed to have flangeless wheels although my LNWR 0-8-0 prototypically does have one set of wheel like this.

 

The chassis were built exactly as designed except that I've chosen to move the cylinders/ slidebars and support brackets out about a millimetre to give me a little more clearance behind the slidebars.

 

What I have found is that on the 36" radius curves it helps to have a continuous check rail which stops any of the wheels which want to go in a straight line and ride up over the outside rail - just like the real thing. I always think of that horrendous curve on the Leeds to Harrogate line at Crimple viaduct when a driver took the curve too fast and luggage came flying down off the luggage racks....

 

As Simon says I  won't be able to run my locos on other layouts so if that is important to you best stick to the standards and 48" radius curves.

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12 hours ago, Coder Tim said:

Thanks for the info, checkrails are a good idea.  I'm going to aim for 48" and see what happens

 If you are going to have a lot of 48" radius (or thereabouts) curvature you might do what I did some years ago when building a layout which was oval shaped and on which pretty well ever bit of track was going to be around 48" radius.  I made up a set of gauges to maximum gauge widening - 0.896" - and built everything,  including pointwork,  to this gauge.   Even on the occasional bit of track which was getting close to straight,  the same gauges were used.   It might mean that you have a bit more sideplay on wheels on some bits of track but nowhere near enough to allow the wheels to drop into the four foot.

 

Jim.

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On 22/01/2021 at 21:34, Coder Tim said:

In terms of what I'll be running, Jubilee 4-6-0s would be the largest regulars but the occasional big Pacific on a funny train would be nice.

 

I imagine that if you want a Jubilee you will either have to scratchbuild it or try to find one of the old Alan Gibson kits. I've just finished putting mine together from the kit. I had to make the boiler (out of a plastic tube and layers of card) and fabricate the slidebars  out of nickel silver strip. These are  rather crude although a Fairburn 2-6-4T built by Alan has something similar. Once painted a mucky brown/grey they become less obvious.

 

And yes it goes happily around my checked-railed 36" radius curves. The wheels are all set to gauge with an SSMRS back to back gauge and are either Markits RP25 or Gibson.

 

There is still some filling work needed before the final paintshop visit.

 

1237035042_IMG_20210124_175258cropped.jpg.12ef11af686a18197df94b0d83bad19f.jpg

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On 28/01/2021 at 14:52, Lacathedrale said:

Just how big is your stack of remaining Alan Gibson S-scale kits, Steve? :biggrin_mini2:

Sadly, I've almost come to the end of the range that Alan Gibson made -

The ones I've completed are

 

MR 3F 0-6-0T 'Jinty' (Alan built this but I've modified it and repainted it)

Fairburn 2-6-4T (I believe this was built by Alan but I've modified it very slightly to run on my layout and finished its livery off)

Stanier 2 cyl 2-6-4T (I have a couple of the 3 cylinder versions in unbuilt format, one of which I'm going to use some of the parts of to build a Fowler 2-6-4T)

MR 4F 0-6-0

Hughes Crab 2-6-0

Stanier 2-6-0

Stanier Class 5 4-6-0

Patriot 4-6-0

Jubilee 4-6-0

Stanier 2-8-0

 

There's also a LNWR 0-8-0

 

There are also probably enough bits to cobble together another LMS Fowler 4F and a MR/LMS 2P 4-4-0 if I can be bothered to do so.

 

Sadly I also had part built Fowler and Stanier 2-6-2Ts which I sold when I had damage to my hand and thought I'd have to give up constructing locos. If anybody knows where these are and would like to sell them back to me I'd love to know.

100_1274.JPG.280a87ef1fc795a1e312767dd0dd57b9.JPG

 

100_1275.JPG.b453ec7e66a31d56e562fde323831775.JPG

 

 

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