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Emily laid bare: A Stirling effort


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Photos taken on old camera so may not be so clear.

 

Emily is a little on the spartan side regarding detail. There is a prominent row of rivets along the footplate that I wanted to reproduce.

 

A row of rivets were impressed into a piece of 10thou styrene with a pounce wheel:

post-3717-0-03761500-1420321170_thumb.jpg

 

The sheet was then carefully trimmed to fit the footplate and glued in place:

post-3717-0-65557900-1420321211_thumb.jpg

 

Having given then a blow over with primer I am hoping they will be more visible in the photographs:

post-3717-0-41826100-1420321250_thumb.jpg

 

As can be seen I have started blending in the joints between splashers and boiler.

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Hi Mike

 

With regards to the buffers, there's two options:

  • Just the buffers - with this option you would need a "deep" flange of .7mm so that they will print.
  • Buffers with the beam - proper scale flanges, and if I can see any rivets on the beam, I can add these too. I'd measure up my Emily, as I have it to hand now, and make the buffer beam the same size as the original. It would also act as a sprue.

Let me know what you think.

 

Also, I will also attach a peg underneath the chimney and safety valve cover, I normal do 2mm diameter, so that they attach to the sprue, it also means you can obviously use the peg for locating the part.

 

cheers

 

Jason

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Mike/Jason,

 

Someone has to ask the obvious question......why not 3Dprint the complete body to mount on  the Bachmann chassis?

 

Sorry, but I have just had a weekend of "hacking" and sometimes question if there is a better way.

 

regards

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Hi Crantock, It's a good point, and I'm not sure I'm qualified to say this in this thread as I am the one who is on the computer, but it's the same reason why I'm butchering a Caley 123 to turn it into an Ivatt 4-2-2 instead of doing a whole body in 3D. I started with the 3D stuff, and realised I really needed to hack at something and make it with my hands. That said, as I'm not about to buy and learn how to use a lathe, so I will still be doing my chimney etc, i.e. stuff I'd have bought anyway, using 3D printing.

 

On that note, here's the latest. Buffers and cylinder caps done - I'll let you hack them around Mike. I'll leave it tonight so you can reply to the bufferbeam question. On that, I might not have said, but if you choose not to replace the bufferbeam, then the collars around the buffers with the bolt heads will have to be thickened up. They pass the automatic checks for the Frosted Ultra-detail material, but may not pass the manual check.

 

I'm not sure what you mean about the tender vents as I don't have them on my plans. Do you have a photo and any dimension ideas? Would the conical vents on the GNR tender I've been doing for the D3 on the beginner's Blender thread in the 3D forum work?

 

post-14192-0-50329200-1420337302_thumb.jpg

 

Some dimensions for you:

  • cylinder end caps, 0.8mm thick, 10mm diameter (https://www.shapeways.com/model/3001918/?li=aeTabs)
  • buffers 8mm long, peg 2mm dia, head, 5.2mm dia
  • chimney 17.1mm from top of chimney to top of boiler, 9.7mm dia at it's widest point at the top
  • Safety valve, 12.2mm top to top of boiler, 12.6mm dia at widest point at bottom
  • Smokebox door from before is 16mm and 2.5mm thick in the centre. The sides are .9mm thick.

cheers

 

Jason

Edited by JCL
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Hi Mike

 

Everyone in my house fell asleep early, so I've managed to do a bit more. Here's the version with the buffer beam. The beam is the same size as the one on Emily. That said, at 5.5mm tall, it's actually not as tall as it should be because the front coupling is there. It's meant to replace the section underneath the running plate. I've also redone the rivets on the cylinder caps, the others were too big.

 

post-14192-0-22504300-1420354840_thumb.jpg

 

I'll bow out again for a while with the photos because I'm sure the good people here aren't here to see computer work but real stuff.

 

cheers

 

Jason

 

 

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Neither can I, but still a lot to do,

 

Jason, happy with what you have done with the 3D work. Yes the conical vents are the ones from your D3 tender. The cylinder covers should have nuts rather than rivets to be strictly accurate.

post-3717-0-24102500-1420366360_thumb.jpg

 

The buffers are also bolted to the beam rather than rivetted.Thickening the smokebox door at the edges to a thickness of 1.25mm would make it the same thickness as the Bachmann moulding.  I think you are right, buffers with buffer beam would be best, however I am open to other's comments. 

 

Regarding the earlier comment about having the whole body 3D printed, yes I did consider it but where is the fun in that? I also suspect it would be considerably dearer. Seriously if I did go down that route I would probably go for an accurate body rather than accept Emily's anomalies.  I would also prefer an etched chassis with correct size driver and if I was going to go that far would probably etch most of the body as well. Isn't there a kit due out for the Stirling Single?  Like Jason I am getting continually drawn towards the earlier periods and quite fancy having a go at a Hackworth engine, perhaps "Royal George" but that is a completely different story. 3D printing would really come into its own then.

 

Once again, thank you to everyone who takes the time to hit that "like" and other links. It is nice to know people are interested.

Edited by MikeTrice
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How much criticism would there be of the compromises that Bachmann would have to strike in order to make a model of such a loco, and how would it actually perform as a traction unit? That picture above so effectively emphasizes the fact that the real thing has absolutely no effective clearances around bogie wheels, mudguards and cylinders. How on earth did the bogie even manage to twitch slightly on its centre pin? Having proven that an Atlantic gear-coupled as a 4-6-0 can easily be made to work, with useful benefits from the exercise too, I'm inclined to suggest that a model of a 4-2-2 ought ideally to be gear-coupled (or even belt or chain coupled) to run as a 2-6-0, probably with boiler as full as possible with lead and maybe with drive taken from a motor in the tender via a flexible shaft. In OO there would actually be some room to let the front wheels of Mr Stirling's engine act as a pony truck to accommodate model railway curves. Best of luck to anybody wanting to build one in EM, P4 or S7!

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How much criticism would there be of the compromises that Bachmann would have to strike in order to make a model of such a loco, and how would it actually perform as a traction unit? That picture above so effectively emphasizes the fact that the real thing has absolutely no effective clearances around bogie wheels, mudguards and cylinders. How on earth did the bogie even manage to twitch slightly on its centre pin? Having proven that an Atlantic gear-coupled as a 4-6-0 can easily be made to work, with useful benefits from the exercise too, I'm inclined to suggest that a model of a 4-2-2 ought ideally to be gear-coupled (or even belt or chain coupled) to run as a 2-6-0, probably with boiler as full as possible with lead and maybe with drive taken from a motor in the tender via a flexible shaft. In OO there would actually be some room to let the front wheels of Mr Stirling's engine act as a pony truck to accommodate model railway curves. Best of luck to anybody wanting to build one in EM, P4 or S7!

Emily has the rear bogie and main driving wheel geared together making her effectively a 2-4-2. This is one of the reasons I decided not to alter her chassis or indeed re-wheel her. It would be nice if Bachmann did a proper Stirling and after the Locomotion Atlantic anything is possible.

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How much criticism would there be of the compromises that Bachmann would have to strike in order to make a model of such a loco, and how would it actually perform as a traction unit? That picture above so effectively emphasizes the fact that the real thing has absolutely no effective clearances around bogie wheels, mudguards and cylinders. How on earth did the bogie even manage to twitch slightly on its centre pin? Having proven that an Atlantic gear-coupled as a 4-6-0 can easily be made to work, with useful benefits from the exercise too, I'm inclined to suggest that a model of a 4-2-2 ought ideally to be gear-coupled (or even belt or chain coupled) to run as a 2-6-0, probably with boiler as full as possible with lead and maybe with drive taken from a motor in the tender via a flexible shaft. In OO there would actually be some room to let the front wheels of Mr Stirling's engine act as a pony truck to accommodate model railway curves. Best of luck to anybody wanting to build one in EM, P4 or S7!

 

What I don't understand is: if the prototype could haul prototypical trains of the period, why can't a model? After all, we hear about models that can haul far more than the prototype, so it's not as though it's impossible to achieve.

 

Phil

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Emily has the rear bogie and main driving wheel geared together making her effectively a 2-4-2. This is one of the reasons I decided not to alter her chassis or indeed re-wheel her. It would be nice if Bachmann did a proper Stirling and after the Locomotion Atlantic anything is possible.

 

Its an interesting concept gearing together wheels of 2 different diameters.  Assuming standard sized gears are used in the gear train, it must drive some compromise on wheel diameters to avoid slippage (which destroys adhesion).  That possibly precludes re-wheeling.  Or is there slippage inherent in the design?  Not an easy one to test.

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What I don't understand is: if the prototype could haul prototypical trains of the period, why can't a model? After all, we hear about models that can haul far more than the prototype, so it's not as though it's impossible to achieve.

 

Phil

 

 

Would you care to show how easily it's done, bearing in mind that forces do not scale in the same way as mass and volume?

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What I don't understand is: if the prototype could haul prototypical trains of the period, why can't a model? After all, we hear about models that can haul far more than the prototype, so it's not as though it's impossible to achieve.

Phil

They can as Hornby proved with the Caly and GW singles. They are easily capable of pulling more than the real thing but they do struggle on really steep gradients especially found on trainsets that you'd expect to find on a Thomas layouts so I suspect Bachmann just played safe. Hornby used 'magnedehsion' which worked on their old steel track.
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I would assume that the gear ratios are such that the two sets of axles rotate at the correct speeds relative to their diameter.

Yes, but I expect that has been achieved by flexing the diameters of the wheels, not the gears which will surely be a standard (ie avaialable off the shelf) size.  

 

Anyway, mustn't distract you from the good work!

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Hi there

 

My part of this has finished now, so I've deleted from Shapeways the individual parts I posted above and uploaded the combined set. This is the link I sent to Mike earlier this evening, so my fingers are crossed they'll turn out ok.

 

https://www.shapeways.com/model/3002316/stirling-single-all-parts-4mm-scale-ish.html?li=shop-results&materialId=60

 

post-14192-0-48286600-1420436616.jpg

 

I can't wait to see how this all turns out. :)

 

In the meantime, back to my GNR A5.

 

cheers

 

Jason

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What I don't understand is: if the prototype could haul prototypical trains of the period, why can't a model? After all, we hear about models that can haul far more than the prototype, so it's not as though it's impossible to achieve.

 

Phil

 

I don't see why this model shouldn't pull quite a respectable load. Even my motorised Kitmaster model (http://www.rmweb.co.uk/community/index.php?/topic/67037-motorising-a-kitmaster-stirling-single/) with just one powered axle easily pulls its 6-coach train, consistent with the illustrations in Leech, KH & Boddy, MG: “The Stirling Singles of the Great Northern Railway” (David & Charles, Dawlish, Devon, 1965)

 

Here she is again:

post-17793-0-16647000-1420441597_thumb.jpg

 

Regards,

Rob

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I'm glad I saw this topic, as I had started converting an Emily into a Stirling single and never completed it due to lack of parts, meant to design some bits for it myself but only got as far as the smokebox door. It's not based on any drawings, I merely took the dimensions from the face and designed one that would just cover it, still needs some work yet but I'm going to order the parts above to complete it. Done a J70 from a Bachmann Toby and currently making a Wisbech and Upwell 04 from the Mavis they make, I just find the models good conversion fodder for what they are. 

 

39AEA7EA-4E8A-4007-8869-451DC73496C2_zps

 

10EF6ABD-7FDD-48CF-BD89-BE68A52891F6_zps

 

42951A16-A01C-47D6-8CBA-6384BAB498DF_zps

 

Not a patch on the work you've done Mike, but I may have to complete mine now!

 

Johnny

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Hi there

 

My part of this has finished now, so I've deleted from Shapeways the individual parts I posted above and uploaded the combined set. This is the link I sent to Mike earlier this evening, so my fingers are crossed they'll turn out ok.

 

https://www.shapeways.com/model/3002316/stirling-single-all-parts-4mm-scale-ish.html?li=shop-results&materialId=60

 

attachicon.gifcombined.jpg

 

I can't wait to see how this all turns out. :)

 

In the meantime, back to my GNR A5.

 

cheers

 

Jason

 

Excellent work- I've ordered a set.  Oh dear I've accidentally added another project to my 2015 build programme :D

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 What I don't understand is: if the prototype could haul prototypical trains of the period, why can't a model? After all, we hear about models that can haul far more than the prototype, so it's not as though it's impossible to achieve.

 

The problem with any single is that the drive is unstable, torque reaction unloads the driven wheel and places much of the weight of the model on the unpowered wheels, and these are much draggier than on the prototype, inside bearings especially so. Compare to a four or more coupled loco, where practically all the weight can bear on the powered wheels, the carrying wheels may be arranged to be lightly loaded 'passengers'. The scheme of gearing together on appropriate ratios the driver and at least one carrying wheelset to make a four coupled or more driven chassis looks to be a good commercial mechanism solution.

 

We can leave the finescale modellers to employ CSB or compensation and ultra low friction bearings to make such a model more like the prototype, which of course enjoys all the benefit of suspension. Though when considering the prototype, there were mutterings about the driver axleload. This design in its multiple developments was shown as having roughly 40% of the loco weight on the driver, rising from 15 tons on the first batch in stages to 19 tons on the final enlargement: there was a suspicion that whatever the various designs may have been quoted at, practical shedmasters will have 'adjusted' them for the job they had to do on the road.

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