Stirling Single Wheeler in G3

[jamiepage]

Jon,
For what it's worth, I'm quite convinced that 1/4in. axles are perfectly fine. Whether live steam or electric.
The legacy 2 1/2in gauge live steam drawings do tend to be 'over engineered' (especially for G3, which is after all scenic railway orientated) with rules of thumb that certainly have the advantage of many years adequate operation on a raised track pulling an optimistic driver, but at the cost of little fresh thinking.
The argument I guess would be 'if it ain't broke, why fix it', but the result can be a lack of progress with little change in techniques since the thirties.
Or some unusual thinking- a published live steam (inside cylinders) design I saw recently had the 'required' 3/8 in. axles- but the front driving axle was then waisted between journals right down to 1/8in. diameter to clear the slidebars etc.
Doesn't really make a great deal of sense to me, to be honest.

Anyway, stepping back away from the soapbox before jumping on, 1/4in will be fine. (Actually, 5/16 would probably be pretty well bang-on scale if you can find a gearbox to suit.)

If I may, I'm also not sure it would be the easiest option to use the cylinder castings you have. To be honest, it is often easier to use stock material rather than castings.
For an electric model it would surely be easier to use stock tube/bar/ sheet as appropriate; maybe tend towards 7mm- type methodologies scaled up, rather than 1930's model engineering standards scaled down.
It will make a lovely model however you do it, that's for sure.

Jamie

 

[Jon Nazareth]

Jamie
Very constructive and all taken on board.
I too thought that the cylinders would be an easier task if made from separate pieces and then soldered/silver soldered together. However, I'm okay if I read or am told that 'you need to do this' or 'construct this item in this fashion' than trying to think it up on my own which, I find very difficult. Do you know of a construction article for making up outside cylinders that don't need to function from a steam point of view? It would be very helpful if you did.

Jon

 

[jamiepage]

Jon,
Not specifically, no. But for an electric loco, the same principles remain pretty well appropriate, whether 4mm, O, G1 or G3.
Guy Williams and Simon Bolton have both produced two books each (maybe more?) covering 4mm loco construction, and I believe Geoff Holt produced one if not two books discussing O and G1 scratchbuilding.
Cylinders for instance, really don't need to be anything more substantial than ends and a wrapper, decorated with detail, all maybe built up on a central core to maintain alignment. Or thin wall brass tubing to give the basic shape, decorated with ends and detailing. All soft soldered.

Even for live steam, with the exception of wheels, to be honest, I much prefer machining a length of bar or other stock rather than castings. Whether cylinders, axleboxes etc it just seems easier. Some more complex items need to be built up and silver soldered into a quasi casting first before machining, but even then they are much easier to hold than an often rough and erratically dimensioned casting.
And that's the rub really. Machining is easy, it's working out how to first hold the things that can get frustrating, with no flat surface, straight edge or reference dimension anywhere.
On top of that, the quality of material is often very erratic- whether cast iron, bronze or whatever, it's frustratingly common to machine away to the final cut only to find a blow hole open up along the way. Or a chilled bit of iron.
The lengths of meehanite or cast bronze you can buy by the inch nowadays are, in contrast, of superb and consistent quality.
Other people will undoubtedly have different ideas though!

Back to the electric model. Following the plans and using the castings (which benefit from the fact you actually have them to hand of course!) will without doubt result in an attractive model so I truly don't want to muddy the waters in any way. But if you have any of the books mentioned you could see how some techniques might be usefully 'scaled up'.
Whatever you do, I shall enjoy watching progress.
Jamie

 

[Jon Nazareth]

Jamie
Thank you again for your helpful comments.
This afternoon, I was machining the driving wheels and getting on quite well until I came across this blow hole! I fed a bit of thin shim into it and it appears that the hole is 7/32" deep and it just didn't seem worth carrying on with the work if that was the extent. I've contacted the 2 1/2" Gauge Association and I'm hoping that they will send me a replacement even though I bought the castings from them a while ago.

Geoff
Thank you for the tip about the batteries. I shall certainly go the route of powering the drivers.

Jon

 

[adrian]

I fed a bit of thin shim into it and it appears that the hole is 7/32" deep and it just didn't seem worth carrying on with the work if that was the extent.

It might be worth trying some metal epoxy repair putty - I suppose it depends how close it will be to the surface. Once hardened it would be machinable. We once repaired a badly pock holed cast iron drilling table with it, it skimmed up fine in the milling machine.

 

[Jon Nazareth]

Adrian
I had thought of doing that but I think that the hole heads toward the tread and once I break through, there'll be a substantial hole. I'll wait until I hear from the Association.

Jon

 

[Jon Nazareth]

P.S. As I will be putting a lot of time, effort and money into this project, I wouldn't want a wheel with filler in it .

Jon

 

[jamiepage]

Jon,
That's a real shame. There's no pleasure to be found in machining a set of castings, never knowing whether or when you are going to stumble across something like that. A sense of relief when they're all finished maybe, but any pleasure on the way has been sucked out of it.

An option which may have legs would be to look at fitting tyres from something more pleasant to machine- meehanite maybe, or steel tube. You only need the casting bit to machine up enough to fit axle, crankpin and tyre. The rest is cosmetic.

I appreciate the diameter suggests there may be significant wastage of material, but it's just possible there is a thin walled steel tube section close to what you need.
A phone call to this chap has worked very well for me in the past.
He certainly knows what's out there and can get rings cut for you if there is anything appropriate. He's also very knowledgable- tell him it needs to be machinable.
Welcome to the Mallard Metal Packs Ltd website
Or some rings could be cut (water, not laser) from steel sheet, then machined. (Cutting tyres from sheet is not altogether the done thing due to grain and stress lines apparently, but it can't be of any significance on a small model).
Jamie

 

[Jon Nazareth]

Jamie
Thank you for the possible solution but I'll wait until I here from the National 2 1/2" Association before I do anything.

On another thread, I'm working on the tender at the moment and good photos of the early ones seem to be quite scarce. I'd like to add some rivet detail to the frames but would really like a decent picture or drawing as a reference. I'll keep looking as something may turn up.

Jon

 

[Steph Dale]

Jon,

There is an original Stirling single tender 'preserved' as part of the National Collection. It looks to be in a pretty deplorable condition and I'm not certain where it is (catalogued as being at Shildon), but maybe you could arrange to photograph it, or get it photographed?

More here: Locomotive tender no. 1002, Great Northern Railway - Our collection - National Railway Museum

Steph

 

[Jon Nazareth]

Steph
That one has outside springs and the one that Mr Hambleton shows in his book 'Locomotives Worth Modelling' as being the original for No.1, doesn't. I'm not a rivet counter but, the drawing/sketch has some nice rivet detail and I'd quite like to reproduce it if I can. Failing that, it'll have to be guess work.

The metal for the stretchers et al arrived today and so, I went back to working on the tender. This afternoon was a bit frustrating as I have a set of frames from one person, a set of drawings from another and I'm also trying to de-strengthen everything (for want of a better word). Both designs are from the 2 1/2" fraternity and therefore are to built with passenger hauling in mind whereas G3 is purely scenic. At close of play, I managed to sort out a few things and the first glass of red slipped down very nicely indeed.

As an aside, I'm posting updates of this project on the G3 Forum so, apologies to those who get caught and have read it twice albeit not word for word .

Jon

 

[mickoo]

Both designs are from the 2 1/2" fraternity and therefore are to built with passenger hauling in mind whereas G3 is purely scenic.

Jon

Interesting following all of this 'large' scale stuff, however the above caught my eye and excuse my obvious ignorance, isn't G3 the same as 2½" or is 2½" not the gauge but the scale.

MD

 

[Steph Dale]

Jon,

That's good! I was just aware that not many people are aware that tender exists. I hope the NRM find the resources to tidy it up...

Steph

 

[jamiepage]

Interesting following all of this 'large' scale stuff, however the above caught my eye and excuse my obvious ignorance, isn't G3 the same as 2½" or is 2½" not the gauge but the scale.

MD

Mickoo,
To quote Simon from yesterday, I may regret this. But.. the answer is yes..and no.
2 1/2 in. gauge refers to model engineering activity, whereby the main interest is to produce a model loco to run on a model engineering club- type elevated track, pulling its driver along behind.

Gauge 3 implies scenic railway modelling, using 2 1/2in gauge track. The locos are important, but form only part of a complete railway modelling activity.

One spawned the other I suppose. Whether it was a natural evolution or more akin to the rebellion of an awkward teenager, or something else again, I don't know, but the two are different. Or which way round it happened either. The history of LBSC designs for the model engineer and BL etc RTR locos for the model railwayist are something I know little about.

Scale-wise, the older 2 1/2 in locos appeared to more often be nominally scaled at 1/24, G3 nowadays is the more accurate 1/22.6 (Well, 17/32 in to the foot).
For good or ill, G3 has inherited 2 1/2in gauge track/ wheel standards, although G3 has finessed it a bit more recently.

Many people are active in both- enjoying their loco both on a raised track (2 1/2in) and on other occasions seeing it run through a modelled landscape with scale wagons etc (G3).
Others have interests in one area only.
The spectrum of activity runs from entirely free lance steamers designed solely to pull driver plus passengers, to the finescale, fully scenicised Spur 2 layouts seen on youtube.
This wide spectrum is a two edged sword- some things benefit the whole spectrum, so that's good. Other things clash with one area of interest or another. Sometimes a great well of engineering knowledge proves to be invaluable, other times 'we always do it this way ' can be a drag.

Optimistically, G3 scenic model railwaying should be capable of taking the best from both the model engineering and the model railway worlds, and apply it appropriately to benefit its scenic railwaying activity accordingly.

Anyway, I do hope more railway modellers will dabble and bring their skills and experience with them hint hint- I'd love to see a Nick Dunhill G3 loco, another top notch build of a Williams wagon kit (as Steve's brake van), an Insole station building, or a Finney13.5 kit, alongside the excellent work of the G3 people on here.
Go on, go on.
Jamie

 

[mickoo]

Ahh, same old story different gravy, a more direct parallel being the recent Gauge 1 viz 1/32 discussion, I get both sides though and take no camp.

There is a sincere boyish pleasure in seeing a live steam engine rocketing along, even if at a scale 300 mph, it appeals to the 'train set' part of me, equally there is a sincere pleasure in ultimate detail and modeling / engineering, both have their place in my eyes and I see no reason to nail any flag to any camp, enjoy each for what they are.

1:32 is about as far as you can go with etch work I suspect' certainly in the frame area, G3 might get away with etched upper works but from what I've seen certainly requires a modicum of 'larger' engineering skills and tool set, not sure I'm up to that at the moment.

Anyway, thanks for the explanation.much appreciated.

MD

 

[Mike W]

Mickoo, I would suggest that Jamie's summary is concise and spot on. Your comment about etched frames being "about as far as you can go" I also agree with. Some very small engines have been scaled up to Gauge 3 with etched frames and they are fine, but I prefer steel for anything larger. I am however quite certain that if you can build an etched kit in 7mm, then a Gauge 3 kit will not be beyond you. My little Manning Wardle was scaled up from John Dale's lovely 7mm kit, but with a redesigned chassis of laser cut steel. the frames and plate crossmembers fit together with slots and tabs, and then solder with ordinary soft solder and an iron - no blow torch. You need a different flux but otherwise its just the same. I now of 0-6-0s, 0-6-2s that have been done the same way and see no reason why almost scale thickness steel frames soldered together shouldn't work for larger engines too, provided they are braced properly. And if you use Slaters wheels the axles and axleboxes are the same size as they use for Gauge 1, so its really not heavy engineering.

Finally, to pick up Jamie's request, if anyone would like to serialise the building of one of my kits I would be very happy to sell them one!

Mike

 

[Rob Pulham]

Jon,

That's good! I was just aware that not many people are aware that tender exists. I hope the NRM find the resources to tidy it up...

Steph

Hi Steph,

They had a fund raiser and have restored it. I thought that I had a better photo of it but I haven't found it so far. - it's in the back of this shot of the Single at Shildon.

 

[Jon Nazareth]

Does anyone know which Model Engineer magazines had Dick Allen's articles on how to build the tender for his Dee? I know it was 2012 but that's all I know. I could do with some pointers

Rob
The tender looks impressive but is the one with outside springs? I'm building the one with inside springs.

Jon

 

[Rob Pulham]

Does anyone know which Model Engineer magazines had Dick Allen's articles on how to build the tender for his Dee? I know it was 2012 but that's all I know. I could do with some pointers

Rob
The tender looks impressive but is the one with outside springs? I'm building the one with inside springs.

Jon

Hi Jon,
Behind the one that you see in the photo is the original tender that was paired with the Single. The one that's with it now (the one that Steph highlighted) is apparently nearer to what was with it originally. I am sure that I have photos of that one too but I will need to search my Flickr site for them.

 

[Mike W]

This one
'The Great Goodbye', Locomotion, Shildon on the 15th Feb | GNR Stirling class A2 4-2-2 no 1
Mike