Copenhagen Fields

[CF MRC]

It’s always a great feeling when a loco has a good first run on the MRC test tracks. The Skittle Alley easily started and ran with 18 on. She will probably take more but the loco and tender are minimally lubricated, so I didn’t want to push it.

 

Tim

[CF MRC]

Making things from scratch is sometimes more straightforward than using components from a kit, as you can design the bits to be held whilst working on them. This was especially true when making the first cross head for the NER 4-6-2 class. The inner crocodile was filed up from 1mm steel sheet, drilled in the end for the piston rod (0.5mm pivot steel) which was silver soldered in place. It was adjusted to be an easy sliding fit in the slide bars with the piston originally being very long to give something to get hold of. The outer pivot and slide bar slippers were made from 0.5mm steel sheet, centred on the 0.4mm diameter pivot hole for the little end, but again with a long handle still attached. 

Having the handle to hold enabled easier filing of the appropriate rebates and surface details. 

The two components were soft soldered together and, once the main filing was complete, cut off from the handle. 

The connecting rod will have a 0.4mm diameter pin silver soldered to its end which will be the little end pivot. This will be retained by a small collar on the outside of the cross head, representing the prototype little end retainer. 

I now need to finish off the second cross head and then the connecting rods. I much prefer steel for valve gear, it is stronger and, being harder, is more forgiving when filing up components - it takes a little longer so you have time to think before you make a mistake - if you understand my strange logic.
 

Incredible what iPhones can do isn’t it?

 

Tim

 

[AdeMoore]

Amazing modelling Tim or should I say miniature engineering!

Edited February 5, 2023 by AdeMoore
Predictive text!

[CF MRC]

The Raven NER 4-6-2 class now has an ‘engine’ with the connecting rods roughed out and the cross heads and pistons in place. The connecting rods will require fluting, amongst other things. 

Tim

Edited February 5, 2023 by CF MRC

[CF MRC]

Perhaps a bit crazy. 

With such large big end bearings, it would have been churlish not to include separate brasses.

 

Tim

Edited February 6, 2023 by CF MRC

[drmditch]

Astounding, amazing, inspirational - and it would still be so in a much larger scale!

Perhaps replicable for other NER outside cylinder locomotives where the drive is onto the leading driving wheel ?

 

Interesting that the connecting rod itself is so massive at the big-end.

On other locomotives (A7/H1/A8 which were also six-coupled and three cylinder) the coupling rod was outside the connecting rod.

(I think, and subject to correction.)

I wonder why that wasn't replicated here?

Edited February 6, 2023 by drmditch

[bill-lobb]

17 minutes ago, drmditch said:

Astounding, amazing, inspirational - and it would still be so in a much larger scale!

Perhaps replicable for other NER outside cylinder locomotives where the drive is onto the leading driving wheel ?

 

Interesting that the connecting rod itself is so massive at the big-end.

On other locomotives (A7/H1/A8 which were also six-coupled and three cylinder) the coupling rod was outside the connecting rod.

(I think, and subject to correction.)

I wonder why that wasn't replicated here?

Midland Compounds had the coupling rods outside too. Maybe in this case clearance issues led to the cylinders being too far outboard for that?

[CF MRC]

They are quite substantial cylinders and the class did have clearance issues, being cut down on the front buffer beam very early on in traffic and the rear valence necked in to give platform clearance. 

Two things that puzzle me are whether the reversing gear balance weight (seen above the frames) was visible when the engine was in forward gear.  Also, at some point, it seems that the wheels had some extra square-shaped weights added to the crescent shape as-cast. My engine will be in near original condition so I suspect it would not have the additions. Any ideas? 

Thank you all for the kind comments - I try to show how it’s done in these posts, not just the end result. 
 

Tim

Edited February 6, 2023 by CF MRC

[Caley Jim]

I would imagine the relative positions of the coupling and connecting rods would depend on where the centre line of the cylinders came in relation to the wheels in plan view.  I would expect the designers would want to keep everything in as straight an alignment as possible?

 

Jim

[t-b-g]

15 hours ago, CF MRC said:

Perhaps a bit crazy. 

With such large big end bearings, it would have been churlish not to include separate brasses.

 

Tim

 

Well worth doing Tim. I did something similar for my 4mm EM "Valour". I adopted a slightly different approach by soldering a rectangle of brass shim to the outside, rather than making a hole in the connecting rod and making a brass insert.

 

Your way would, I think, be a little more difficult to do but I am sure you will have a good reason for going down that route. You usually do! I would be interested to know why as it might influence my decision next time around (7mm Valour, 7mm and 4mm B7s).

 

[CF MRC]

I recollected you doing it for Valour, Tony. I didn’t fancy sweating on a bass facing, bearing in mind that the nearby flanges of the rod are also soldered on. It didn’t take long to make the square hole with an escapement file and then trimming a block of brass to fit. 

 

Tim

 

[nick_bastable]

it appears Im not alone in scoring the top of the vice jaws

[micknich2003]

Nick, don't worry, I have managed to mill a slot in my machine vise.

[richbrummitt]

1 hour ago, micknich2003 said:

Nick, don't worry, I have managed to mill a slot in my machine vise.

hasn't everyone?

[CF MRC]

Holding your work whilst working on it is one of the biggest challenges in 2mm scale (and others). The simplest way is to glue the component to a bigger piece of metal to hold in the vice.  The holding area can be flooded with a puddle of fast setting cyanoacrylate and then the rod dropped into place: the glue is then ‘set’ with some accelerator liquid. The photo below shows how I set up the con rods for re-drilling the big end holes in the brasses. The measured position from the little end was marked with a fine marker pen and then the table shifted on the axis using the dial from the little end reference point: the drill more or less landed on the spot (I erred on making it a touch shorter). Removal and clean up with a scalpel blade is straightforward.

Once it all felt pretty free, the temporary plastic insulation collar was replaced with a steel version. The top of the cross head was coated with a black indelible marker pen, to act as an anti-flux. The steel collar was cut from a 0.4mm bore syringe needle.

A minuscule amount of this German flux was applied to the tip. This flux is excellent for steel, it is a bit ‘oily’ and very corrosive. 

The iron is brought into contact with the pin and flux with just a small amount 145 degree solder on the tip. It boils up the flux and the solder immediately flashes into the joint, at which point the iron is removed, of course.  I have never got on with cigarette paper washers when assembling valve gear as they make the joints too sloppy. 

The con rods are a very close fit to the slide bars at top and bottom of the crank throw, but they just kiss past, I don’t think the bars will need any adjustment. The big end will probably have a turned collar made for it. 

The alignment on the frames, wheels and valve gear is quite satisfactory, without any nasty bends anywhere: an advantage of working to a true scale / gauge. 

The front steps will need to be robust and well fixed as they must not touch the connecting rod (at least on one side).

 

Tim

 

Edited February 8, 2023 by CF MRC

[CF MRC]

Little & LARGE. The driving wheels on the Raven 4-6-2 class have been lined out, just awaiting the black axle ends. Meanwhile, I have started to fettle the cast lamp brackets for my 3.5” gauge King Arthur, Sir Sagramore, in a scale approximately an order of magnitude bigger, i.e. 1/152 vs 1/16 full size.

Once the Skittle Alley is re-assembled I’ll probably work on the KA (see separate thread) for a while. 

Tim

 

[CF MRC]

Measuring spot heights on locos / rolling stock can be achieved using surface plates and gauges / markers for model construction. My take on this is to use a piece of Tufnol with some PCB  ‘rails’ set tight to gauge to locate a chassis very precisely (i.e. no side movement on the wheels). This block also has a coupling height gauge incorporated. 

The way it is used is that a digital vernier is zeroed on the thickness of the block and ‘rails’. The block material needs to be of consistent thickness, but also quite hard and shiny to allow a vernier jaw to slide easily. The loco is positioned on the block, being held with one hand, and then the callipers used to make measurements or perhaps scribe a line for e.g. handrail stanchions.

The photo shows that the Skittle Alley boiler height is a fraction under, but should be about right when it gets a coat of paint…

 

Tim

[CF MRC]

The Raven 4-6-2 class is now mechanically complete. It slightly ‘stuck its elbows out’ on the slide bars when running and so a restraining wire was soldered across the back of the crocodile, using 145 deg solder. 

https://youtu.be/EoCENm7k2bI

 

The driving wheels are lined out at the hub but the rims are not yet black. 

 

Tim

[CF MRC]

Darlington works has been a bit quiet of late with a slight diversion into 4mm scale scenic modelling for the MRC’s OO layout. However, I did make the cab sides for the NER 4-6-2 class at the Missenden modelling weekend. 
 

Subsequently, the spectacle plate was made from quite thick brass as well as the running plate top. This is 5thou steel shim, being stronger than brass or N/S and able to take a good chemical blacking.  The cab sides were obviously made as a pair, sweated together for cutting and filing. 

 

I decided not to put on the external cab window beading as it is very fine (in reality) and generally gets in the way of the black and white lining. The cab window frames are required, however, but only one is visible as the engines always ran with the rear window slid forward. Representing the rear slides was worthwhile and will also gave a greater surface area for soldering on the roof at eaves level.  The window layer was aligned using a couple of stainless steel pins through the handrail knob holes whilst soldering. 

Next stage was to get the cab erected and the footplate extension boxes in front of the spectacle plate. 

The rear cab roof support was made from thick brass and the whole assembly held in place with two bolts - the engine is being designed with ease of painting in mind, breaking down into useful sub-assemblies. 

The next job will be to make the styrene pattern for the back head, which substantially fills the cab, seats and cab floor. A good job for demonstrating at Ally Pally next weekend. The loco now looks that little bit more complete. 

 

Tim

Edited March 14, 2023 by CF MRC

[CF MRC]

A significant change of style has seen quite a lot of work expended on the Vale Royal board (situated west/ behind Belle Isle). This has always been rather sketchy in its presentation, which works, up to a point…

 

We were fortunate to inherit some fine industrial buildings from the old ‘Hill End’ 2mm scale layout. I suspect these were made by Ray Fricker. They have been useful to add interest into our industrial hinterland. 

At the same time, the south end of the Tylor building has been lowered by 8mm to give a better relationship with the Vale Royal road. 

The medium and far distant houses have also acquired rear extensions, garden walls and trees. 

We will need to see how all this works with the layout fully assembled and how much more detail could be added. CF has always been a layout of broad brush strokes. Indeed that has literally been the case over the last working sessions as it has had a major clean up.  
 

I’m looking forward to seeing it all together at the Bristol Show in Thornbury at the end of the month. 
 

It is exactly 40 years since John Birkett-Smith, Mike Randall and I started planning the layout. 
 

Tim

Edited April 14, 2023 by CF MRC

[CF MRC]

Our first show to demonstrate the layout concept was at the last IMREX at the Wembley Conference Centre (probably 1985). We were on the balcony, showing Bill Blackburn’s impressive track making jigs and other display bits, such as the model of the model. 

During the show an elderly gentleman and his son enquired on the stand, “Why don’t you use the new PECO track?”  I replied that this layout was going to be 2mm finescale and that it would be incompatible. He responded “I’m sure you could get a good deal”. Again I said that it was incompatible with the wheel standards, asking him who he was. “Sidney Pritchard”. He walked off muttering to Michael…

 

Interesting how things turn out isn’t it? We certainly didn’t expect to still be working on it nearly 40 years on.

 

Tim

 

 

[Yorkshire Square]

12 hours ago, CF MRC said:

Our first show to demonstrate the layout concept was at the last IMREX at the Wembley Conference Centre (probably 1985). We were on the balcony, showing Bill Blackburn’s impressive track making jigs and other display bits, such as the model of the model. 

During the show an elderly gentleman and his son enquired on the stand, “Why don’t you use the new PECO track?”  I replied that this layout was going to be 2mm finescale and that it would be incompatible. He responded “I’m sure you could get a good deal”. Again I said that it was incompatible with the wheel standards, asking him who he was. “Sidney Pritchard”. He walked off muttering to Michael…

 

Interesting how things turn out isn’t it? We certainly didn’t expect to still be working on it nearly 40 years on.

 

Tim

 

 

You'd have had it finished thirty years ago if you'd used PECO! 🤣🤣🤣

 

Happy 40th guys. You're an inspiration to all of us. Keep up the good work!

[CF MRC]

9 hours ago, Yorkshire Square said:

You'd have had it finished thirty years ago if you'd used PECO! 🤣🤣🤣

You may well be right. However, I don’t think the area could be modelled (properly) with commercial track.

(photo Barry Norman, courtesy MRJ)

One of the great strokes of luck during its construction was the acquisition of a copy of the LNER track diagram dating to 1932. One of our club members  is a great collector of antiquarian railway books and ephemera. He was tipped off by the auction house, for which he was a major client, that they had a copy of the LNER engineer’s track plan for Belle Isle and the KX Goods Yard for sale. Due to his standing with them, we were allowed to borrow the plan for a few days. It was a simple job to get the drawing scaled to exact 2mm scale in a print shop and run off a couple of large copies.  

We therefore had an accurate track plan in the early 1990s, well before Templot was invented. The late, great, Keith Armes made all the track work in the Belle Isle ‘trough’ and commented that the turnouts and crossings were the longest he had ever made. GNR drivers didn’t hang around getting into the ‘Cross from Finsbury Park, so the cross overs on the up lines were clearly built for speedy transitions. 
 

Tim

Edited April 16, 2023 by CF MRC

[martin_wynne]

2 hours ago, CF MRC said:

We therefore had an accurate track plan in the early 1990s, well before Templot was invented.

 

Hi Tim,

 

Before Templot was publicly available, but not before it was invented. The first usable version was in use in 1980. The first public release was in 1998.

 

cheers,

 

Martin.

[CF MRC]

As an aside, a friend has just turned up this guide photo of Chiltern Green. 

Had darker hair then, but I’d only been married six months at that time. 

 

Tim