Saturday, 9 December 2017

December 2017 meeting

Simon, Jim, Stephen, Alistair and Graham met at Alisdair's house in Glasgow on a cold but bright day. Some of the keener group members had found time to advance their projects in the last month. Simon had worked on some Severn Models etches to good effect: a signalbox in a fetching shade of pinkish primer:

and a weighbridge and office:
Both were made up just for fun, with no particular plan to use them in a model.

Stephen had a Dave Bradwell J27 etch resurrected from his Round Tuit box of stalled projects ... it sits on a Bob Jones chassis which was too shy for a photo:
Jim's signalbox for Kirkallanmuir was shown in flat form in last month's thrilling blog entry. This month we got to see it in built-up form :

 and some of the interior detailing: the train register desk and chair:

Took him ages to make the overscale penny though.
The cunning jig to assemble the treads of the access stair was also on show. Here's a view from each side:

The stair treads are individually etched pieces with small tabs at each end. The slots along the bottom of the jig accept the treads, and are differently-sized: the width of the tab on one side, and the full tread width on the other. The distance between the sides of the jig is slightly less than the tread length.

The treads are fed in through the larger slots so that a tab locates in the smaller slot on the other side. The tab at the other end stands slightly proud of the jig. The treads are thus held firmly while a pre-assembled etch for the stringer with slots to receive the tread tabs and handrails attached is offered up, the treads teased into the slots, then soldered with the merest trace of solder paint and a quick dab of the iron. The assembly is gently extracted and placed in the open slots at the top of the jig, and the stringer and rails for the other side of the steps is soldered up in turn. Clever stuff, and the result is worth the trouble.

Time was pressing however so the models were tidied away and Alistair gave us a short treatise on creating a backscene. Larger scales, he told us, may be able to get away without a backscene in some cases, but in 2mm it is essential. It has to be removable so that it can be worked on easily if necessary. Some notions on how to arrange this were sketched out for us:

As for what material to us: decorator's lining paper seems promising but in practice absorbs large quantities of water and expands as it does so, making dimensional stability a problem. Artists customarily prepare paper by stretching it on a board (soaking it, wiping off the excess, then taping it firmly down to the board while at maximum state of expansion and leaving it to dry overnight) but this is impractical for very long strips of paper. Thick watercolour paper will not expand as much but is too expensive to use for large backscenes. Instead, thin white card (from an artists' supplier or even framer's offcuts), carefully butt-jointed with reinforcing strips glued behind was recommended, with white emulsion as a base coat and used to fill any tiny joint gaps by careful use of a spatula.

Artists' acrylic paint is Alistair's preferred medium, giving good colour depth and being easy to use if care is taken to prevent them drying out on the brush. No need to buy expensive individual tubes of artists' acrylic: the inexpensive sets available in WH Smith such as Windsor & Newton "Galena" or Daler-Rowney System 3 are perfectly adequate, with a good range of useful colours, and tube sizes more suited to 2mm work. The cheaper paint contains more filler and less pigment - which makes their colours less intense - but for backscene use, intensity is not the main consideration. It's worth buying a larger tube of white, since it will be used four times as much as the other colours. Dark colours tend all to look similar since they are close in tone. To achieve a clear differentiation, lighter tones work better.

The first question was how to deal with sky. Alistair showed us how to mix white with cerulian blue and a tiny touch of ultramarine to get a convincing shade. A grey sky is achieved by adding a touch of burnt sienna. Sky tone is lighter where it meets the horizon and deeper straight overhead. Work with a wide, flat brush to cover the paper quickly: keep water handy because the acrylic will dry our on the brush very rapidly.

Deep blues from different suppliers may not act the same way when diluted and spread out over an area - some may have a reddish tint; others greenish.

Like all water-based paints, acrylics' shade lightens slightly as the paint dries, so it is necessary to work slightly darker than the desired end result. The change is not very marked in acrylics and is really only an issue when trying to match an existing tone of dry paint on scenery. (Acrylics' use is of course  not restricted to backscenes: Jim told us how he now uses them exclusively for wagon lettering). An old trick is to hide the backscene/scenery join with a wall or trees.

Some colours are essential in the backscene artist's palette: white, and a dark and light yellow, red and blue respectively. Alistair mentioned titanium white, lemon yellow, cadmium yellow, cadmium red, alizarin crimson, ultramarine blue and cerulean blue. Some other harder-to-mix colours are convenient to have at hand: yellow ochre (especially for mixing to create grassy shades), burnt sienna, and a yellowish or bluish green.

For detail, a "rigger" brush, with long bristles to hold a decent load of paint, is a good choice. The name apparently derives from artists depicting the rigging of nineteenth-century ships.

The backscene should not impose itself. Detail should be minimal and tones muted - as exemplified by models such as Anthony Yeates' "Corrieshalloch" and taken even further in the monotone background of "Lighterman's Yard". True perspective often looks wrong in a backscene, since it can only be accurate from one viewpoint. Instead, parallel perspective is a better choice: not completely correct from any viewpoint, but adequately convincing from most.

A very useful talk - thanks Alistair. The bacon sandwiches were served up, the scones and mince pies were handed round. All disappeared quickly. Then some more detailing work was done on "Sauchenford" - adding the characteristic A-frame telegraph poles used on the main pole routes of the Caledonian Railway. These were made up by Alisdair from kebab skewers shaped to a taper in a minidrill using coarse sandpaper, with crossbars from Jim's etches:

It's interesting how much character it adds to a scene to have some tall verticals - telegraph poles and signals - alongside the railway.

I am always fascinated to see other modellers' toolboxes: here's a shot of Jim's travelling kit to close with, in a sturdy wooden box which apparently once held rolls of camera film.

Next month's meeting will be in Edinburgh, on January 13th. For a change, the talk will be about the prototype rather than modelling, specifically on the Kenyan metre gauge, and the revival of a 1920s Vulcan Foundry 4-8-0. New attendees are welcome, just let Alisdair know you're coming.

Saturday, 18 November 2017

November 2017 meeting

Alistair, Alisdair, Andy, Stephen, Jim, Graham and new boy Chris assembled in Edinburgh this month. The temperature left no doubt that it was November, but the sun was shining.

This month's talk was by Jim, who swapped his Swiss needle files for the computer variety, in order to explain the gentle art of designing etched kits to us. Jim has commercialised some of his designs through his Buchanan Kits label, but he also produces one-off models for his Kirkallanmuir layout using etches, which he prepares himself using AutoCAD.

First of all Jim took us through a brief description of the principles of etching. Rather than repeat this blow for blow, the interested reader is referred to Bob Jones' excellent etching treatise on the 2mmSA virtual area group website. You can't access the VAG? Join the 2mmSA and see what you're missing!

Jim has used both of the main UK photo-etch suppliers, PPD and PEC, each of which has its own advantages and disadvantages. PPD dip their etches, PEC spray; PPD use rolls of metal, PEC use flat sheets; PPD offer smaller minimum sizes and setup costs, PEC are cheaper pro rata in bulk. The differences were explained to us. Search the VAG for "Etchers Advice" to read a series of very useful reports from experienced etchers in February 2016.

 Jim had brought along his most recent etch design and the outome in 10-thou nickel-silver: £109 from PPD, who are very responsive: two weeks from artwork submission to give a quote for approval, with five working days quoted to make the etch (in fact the order turned up two days after payment). PEC are typically slower.

The artwork for the etch is displayed on the monitor, and the finished result is on the table. On the left is a signalbox for Kirkallanmuir; on the right, a Caledonian Railway brakevan. Odd spaces are filled in with useful parts like hurdles for loading cattle, telegraph pole crossbars, and so on.

"Etch that, Jimmy" ... a traditional Glasgow greeting.

Etching artwork consists of four congruent layers, controlling how the nickel-silver is cut by the chemical etchant: leave the metal as full thickness; half-etch from the front; half-etch from the back; or etched right through. Jim uses AutoCAD 2007 to prepare his artwork, with two added preliminary layers: 0 for an outline drawing of parts using a zero-thickness line; 1 for a construction view (just the outline of areas of etch which belong together, used for placing the designs compactly in the final sheet layout); then finally the four layers copying layer 0 and filling in its shapes by hatching, to tell the etcher what to do: 2 to show where metal should be etched right through; 3 for "etch from front"; 4 for "etch from back"; and 5 for "etch right through".  PPD and PEC use different conventions for whether black mean "etch through" or "full thickness". Personal preference for one or the other when drawing may therefore influence the choice of etcher. Another factor is the drawing format they will accept: PEC for example standardise on AutoCAD 2000.

Jim took us through the design of a wagon, starting by drawing the floor outline on layer 0 with zero-thickness lines spaced 0.15mm apart for planking, step-copied as an array to be over length then trimmed back. Next, the inner layer of the three-layer etch for a side is drawn, and mirrored over to the other side; then the outer layer similarly; then finally a strapping layer. Each side Z-folds together like a concertina, with fishtail hinges which are filed off after the layers are sweated together. Jim explained the difference between a fold (90 degrees) and a bend (180 degrees), and how to get the dimensions of these correct. Then the ends are added in the same way, and solebars, headstocks, axleguards, axleboxes, and end stanchions. Veritable origami in ten-thou metal sheet.

Other tricks of the trade included tab-and-slot design - the slot 0.1mm oversize,  the tab tapered to make fitting easier. Multilayer parts don't always fold perfectly so a little tolerance is a good idea: multilayer axlebox bearing holes slightly oversize, and more generous hole sizes on the inner layers of a multi-layer part. This also give somewhere for the solder to go. Bolthead relief on outer layers is best added by half-etching from the back, then pushing a needle through from the back to create a pimple. Small multilayer parts are much more easily manipulated if an etched handle is included, removed once the part is soldered in position. Fitting of parts like coupling hooks and brake levers is eased if a tiny step is designed in at the appropriate point so that they locate correctly on assembly, avoiding the need for a shaky hand to hold them in place while soldering and the consequent risk of a dry joint.

There were more words of wisdom and experience, but at that point I went off to prepare lunch. Jim had brought along his latest build of his own etches, in the elusive Dixon livery which was a very common, but little-photographed private owner livery around Glasgow. Usually a shot like this has to be excused with a  caption on the lines of a "cruel enlargement". Not necessary here: the closer you get, the better it looks.
After lunch everybody got their heads down for a bit of modelling, while Alistair invigilated, as befits a retired dominie. It was dark by the time we stopped for more discussion, tea, cake, then off home.

Quite a productive day for us all. Next month, we'll meet in Glasgow.

Saturday, 14 October 2017

October 2017 meeting

We were back in Glasgow for this month's meeting. Alisdair hosted and Andy, Stephen, Gordon, Jim and Graham turned up to hear him explain some of his techniques for making plasticard buildings.

Alisdair uses several layers for most buildings: a 40 thou shell with the windows and doors cut out by scoring the shape with a scalpel, scoring diagonally across, drilling holes at the corners, then cutting and snapping out the triangles and cleaning up with a file. The process is repeated for an outer skin of textured (stone or brick) styrene, or by placing individual stone blocks. Window frames and glazing bars are produced by placing long strips of 5 or 10 thou inside the shell, which keeps all the horizontals horizontal, and filling the gaps with pieces to create the vertical part of the frame. Uprights to strengthen the shell at joints and corners are best left over-length at the base so that they can be set up truly square, then allowed to set firm and trimmed several hours later. A large file helps make the base of the building truly level. We were shown a stone shed demonstrating the principles.

To prevent the styrene bowing inwards, Alisdair fabricates a temporary separator which when put in position exerts a slight outward pressure on the walls of the completed building. This is removed after a few months, after which the walls stay flat for years. A handy tip.

Alisdair uses four different glues and solvents: Limonene, the least aggressive and slowest acting; Butanone, faster acting and more aggressive; Humbrol cement, often his weapon of choice, very smelly but very effective: too aggressive for 5 thou which it just dissolves; and Tamiya cement which has the advantage of filling gaps.

Alisdair's most recent essay is a sewage works destined for Tony Heywood's Tebay project. Tony had supplied prototype photographs and (too late for the model, unfortunately) was also able to obtain plans from the helpful water board. Here's the model half-way through construction.

Next, we were treated to a display of models wot he'd prepared earlier (in some cases, several decades earlier). Here is Newtonmore station building (on the Highland main line). The section with the columns under the roof is separate, to allow easier painting of the details - the split between the cast iron columns and wooden brackets can be seen in this shot.

On the non-rail side of the building, the red dot of the postbox draws the eye immediately, an old artist's trick.

Carr Bridge, on the Aviemore-Inverness Direct part of the same line, was a  wooden prototype in the vertical board with capstrip style familiar from many other HR stations. Again, the section under the roof is removable. The paint job is not yet complete.

Woodside and Burrelton was a small station on the Strathmore section of the Caledonian main line in the company's standard style.

A two-storey house in brick. I missed hearing what the prototype was, or maybe it was freelance.

One of the Highland's characteristic signal cabins, painted in HR colours from an old Model Railway News article by Sir Eric Hutchinson which turned out to be inaccurate, as Alisdair ruefully explained. The model still captures the essence of the prototype beautifully. This design was to be found all over the Highland system.

Something different: a Highland Railway footbridge of the Rose Street Foundry pattern, from the Lochgorm Models kit. Fun to build, Alisdair told us, but demanding, and requiring choice language from time to time. The result is worthwhile though.

Jim had brought along the completed warehouse for his Kirkallanmuir layout which was mentioned in previous blog entries. The final version uses a laser-cut MDF shell with inkjet-printer paper overlays and etched window frames and doors. The building's extension has lighter-coloured stonework and roof slates to represent less-weathered recent construction.

Jim also showed us his research for Kirkallanmuir signalbox (discussed here on the Caledonian Railway Association website). This promises to be a nice building. After a bit of arm twisting Jim agreed to give a talk on his etch design methods at our next meeting (on November 18th in Edinburgh, if anyone is interested in coming along. Contact details are in the 2mmSA newsletter).

A little more work was done on Sauchenford's point rodding, and large quantities of rock buns, fruit cake, bacon rolls, tea and coffee were consumed. Only at the end of the day did Alisdair reveal it was his 36th birthday ... well there was a 3 and a 6 in the number anyway ... too late for us to get out the party hats, but we'd had a very satisfying time and learned a few more techniques. A good day.

Saturday, 16 September 2017

September 2017 meeting

This month's group meeting, in Edinburgh, was sparsely attended. Alisdair, Andy and Graham gathered to progress the point rodding on Sauchenford.

First though Alisdair shared some of his recent modelling: the filter tank for a sewage farm (no, really) which posed an interesting problem since his chosen prototype has masonry walls with a noticeable batter. The shape needed is a slice through a cone.

Alisdair's first thought was to wing it, slapping together two plasticard discs separated by a spacer and side walls made up of flat segments. After strips of Wills stone pattern styrene were glued in place and the whole thing sanded down a bit, it would look fine, he thought. Except that it didn't; it remained lumpy and unconvincing.

So another attempt was made, this time drawing out the wall as a flat sheet before curving it into a three-dimensional shape. Alisdair explained that he was able to do this quite simply, by making a trammel, pivoting it near the edge of a sheet of plasticard, and using a scalpel fixed to the trammel to cut two lines giving the correct shape. I have no idea how he knew to do that (perhaps he was in contact with David Eveleigh, who bases whole layouts on conic sections, or perhaps he simply paid more attention in maths than I ever did). Anyway this technique worked much better. The correct name for the shape of the tank, so the Interweb tells me, is a frustrum (no wonder). Several web sites explain how to draw it out (for example, here). Alisdair found that, if he nicked the rear of the stone-sheet strips and bent them slightly (the whitish marks in the shot below), they followed the shape of the wall much better. This is how it looks even before sanding down to reduce the overscale stone courses. 

Alisdair has also been experimenting with Scalescenes downloadable brick and slate sheets to construct other buildings for the sewage works. He found he was able to change the colour cast and tile size of the sheets with a graphic editor to give the effects he wanted. We look forward to more details as his investigations proceed.

After our lunchtime bacon rolls, we got on with the task of assembling the point rodding stools (made up from Laurie Adams' etches, see last month's blog) onto small bases of black card, ready for planting on the layout. Alisdair soldered up a rodding compensator from the Association etch. The results of all this labour may need a little tweaking for straightness but are reasonably effective from normal viewing distance, even when not painted or weathered, and with the glue still wet. 

On its own this short run is not very visible, but the overall effect once all the rodding is in place should be worthwhile. It had better be, after three of us going cross-eyed all afternoon ... 😲 

Sunday, 13 August 2017

August 2017 meeting

For our August meeting we abandoned our usual alternating meeting venues of Edinburgh and Glasgow, and drove through the light drizzle to Biggar in South Lanarkshire, whose 2300 souls punch above their weight in terms of preserved gas works, vintage vehicle festivals, proper butchers and bakers (very possibly also candlestick-makers), and so on. Just about the first thing you learn from its Wikipedia entry is that it was served by the Caledonian Railway. The perfect place, then, for a 2mm area group meeting.

Our destination was Jim Watt's double garage, where we were promised not just space to erect Sauchenford, but the chance to check on the progress of Jim's Kirkallanmuir project, which he has chronicled from time to time in the 2mmSA magazine, starting in the June 2011 issue.

First, then, Sauchenford. The scenic section, cassette fiddle yards, and support substructure had been brought from their three separate storage locations, and the aim of the day was to change the layout height by shortening the legs to give our preferred track-height-above-floor dimension of 3'9".

The first job was to erect the substructure with its existing legs upside-down, using the cassette fiddle yards as supports. (And we wonder why the track on them gets damaged!)

New support struts were marked and drilled, then the legs were carefully measured three times, checked twice, and cut once.

In spite of this, we managed to cut one of the legs half a centimetre shorter than the others. We may shortly be ordering levelling feet from that nice Mr Sissling in Bradford ... at any rate, the substructure in all its splendour could now be erected the right way up:

and the layout popped on top, with its new lighting installed. By this time we were full of excellent home-made tomato soup and proper breakfast rolls with copious quantities of bacon from the aforementioned bakers and butchers. The proud parents thus adopted expressions of dreamy contentment, and a wee running session ensued.

Of course what we had really come to see was Kirkallanmuir, Jim's essay on the mineral railways of South Lanarkshire, which is now essentially in working order and ready for scenic treatment and buildings. The following pictures were taken in available light without a tripod so perhaps don't really do justice to Jim's work, but hopefully they give a flavour. Click on the photos for an enlarged view.

Kirkallanmuir's back story is a single-line country branch of the Caledonian Railway. Originally a terminus, the line was doubled after coal mining began nearby, and was extended on into the wilds of South Lanarkshire as a single line. A new through passenger station has recently been built, the old terminus becoming the goods station; a mineral railway connects nearby collieries to the weighbridge at Kirkallanmuir; and a small storage yard is provided for weighed full loads and empties waiting to go up the branch. A cattle bank and agricultural warehouse bear witness to the farmland surrounding the colliery screens and slag heaps. There is no engine shed, but a small turntable allows tender locos to work terminating trains. The whole thing is on three one-metre baseboards, with the double line, mineral branch, and new passenger station represented by cassette storage yards, and the old station, turntable, and wagon yard fully visible in front of these.

Here is the empire with the emperor:

On the board closest the camera, the double-track line from Bonkle is on the left foreground; the colliery branch is in the middle; and the storage yard is on the right, on the viewing side of the layout. The cattle bank and warehouse form the backdrop of the middle baseboard, with the turntable next the viewing side: the mockup card hut marks the site for the Kirk of Allanmuir (to be modelled on Jim's local church). Finally on the left side of third board, the ends of the passenger platforms are just visible through the bridge forming the scenic break as the line theoretically carrying on to Wilsontown, while the goods station is to the right, next the viewing side.

Here's the view from the other end. The ballast colour differs between the yards and sidings, and the more carefully maintained running lines, which are also modelled slightly higher by packing the track with thin card.

The goods station yard has yet to gain its shed and loading banks, but is already full of stock.

The agricultural store in the next shot is a second incarnation of the model Jim made as part of the Group's cameo challenge, written up in the magazine earlier this year. Jim went ahead with his intention to use laser-cut 1mm MDF for this structure, in order to get crisper cuts for windows and doors. The results justify the effort. No doubt Jim will report on this himself in due course.

The central board has some attractive views of trains as five threads of activity take place: occasional shunts to the cattle bank sidings at the rear; passenger trains moving through the scene adjacent to them; constant movement over the goods station throat immediately in front, as the yard pilot sorts wagons; colliery traffic arriving over the weighs, then reversing to the storage sidings (or, alternatively, full loads being drawn out from storage by a pilot then reversed to depart behind a train engine towards Bonkle); and finally, closest to the front, the turntable. In this picture, a passenger train arriving from Bonkle waits for the signal to enter the station.

The loco, a Drummond 171 class 0-4-4T (which, as Jim won't tell you, was derived from a North British 4-4-0T design), shunts its empty stock, while the yard pilot, a 29 class 0-6-0T, sorts wagons.

The signalbox will be on a restricted site opposite the water tank, and so will be an oversailing design.

Jim's 0-4-2 tender loco No 319 emerging from the turntable road. To the left is the weighbridge hut.

Finally some views of the third board. The road to the station is carried over the various railway lines by light plate-girder bridges modelled on surviving CR structures in South Lanarkshire. Here's one of them, spanning a tandem turnout with loose-heel switches and typically rough yard track.

The storage sidings are almost full.

The 29 class, and a 498 dock tank, sit in the brake van lye.

Jim's method is to bring together elements from observed Caledonian practice rather than slavishly model particular structures or layouts, so that the goods station has traces of Blairgowrie in its pedigree, the passenger station of Strathaven, the signalbox will be inspired by Strathclyde Junction, and so on. 

Kirkallanmuir, seven years in gestation, was delayed by an extended house move saga, but activity is once more in full gear. We look forward to seeing the layout again once scenics have progressed further.

Alisdair, over the last month, had assembled some of Laurie Adams' point rod stools etches for Sauchenford. He asked me to take some pictures, but in honesty I could hardly see them, never mind photograph them! Here they are anyway:

Fortified by yet more tea and coffee, we packed up Sauchenford and headed back to our respective homes through late afternoon sunshine, with many thanks to Jim for his hospitality and for the peek at Kirkallanmuir.