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About this blog

Reports on my 2mm finescale modelling of the Highland Railway in the Edwardian era. I'm moving over from Blogspot (http://ayeates2mm.blogspot.com).

Entries in this blog

Scrap Tank - valve gear

This is the first time I've attempted outside motion, so apologies to the experts. I've concluded that it's rather small and fiddly, but no more so than other fine details.   First off, I drilled, sawed and filed up the connecting rods in the same way as the coupling rods, from two sheets of 15-thou nickel silver sweated together. Here you see them once the paper pattern has been removed. They're shape is supposed to be a simple approximation of the real thing. As you can see in this e
antyeates1983

antyeates1983

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Scrap Tank - splashers

After a delay while I ordered some suitable brass tube, I've finally added the front splashers. I didn't fancy trying to bore these out of brass bar, and in any case didn't have any of large enough diameter. Instead, I had the idea of using brass tube. First step was to solder a sheet of 5 thou brass to the end.   This was then cut as close to the tube as possible with a Stanley knife. Then, it was chucked up in the lathe and turned down to the correct diameter, which was slightl
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antyeates1983

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Scrap Tank - smokebox door

Today I decided to turn the smokebox door from brass rod. I didn't have any hard dimensions to go by, so just estimated something from photographs. Here are a couple of photos of the workpiece in the lathe. I first drilled a 0.4mm hole in the end - this will take a piece of wire to hold the handles. I then had a go at forming the domed end. I didn't take a photo at that stage, so the first photo here shows me with a different tool installed that I have just used to remove the material behind the
antyeates1983

antyeates1983

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Scrap Tank - shaping the chassis

Having drilled the holes in the frames, I stuck on a template again and cut around it in time honoured fashion with a piercing saw:   Files were then used to finish the shape. As you can see, these include crude representations of the springs (just shadows behind the wheels, really). Shaping (and thinning) of the guard irons will be left until later. The extra material at either end was to facilitate clamping during the drilling operations but shouldn't be needed any longer.
antyeates1983

antyeates1983

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Scrap Tank - safety valve

The photo below shows the safety valve "saddle", as well as the tank filler caps (which were straightforward turnings from brass rod). The saddle was made in the same way as the new dome, with a thin flange squashed on to a rod. I soldered a spigot up inside it, and used this to hold the assembly while drilling out the three holes on the Proxxon milling machine. The front hole is for the whistle.   The two main valves (not sure of the right terminology!) were made from 0.8mm bras
antyeates1983

antyeates1983

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Scrap Tank - plates and handrails

Here's a photo of the loco before the details referred to in the title were added. In this picture the motor is not fitted, so the cab looks empty. I was running it up and down the track under gravity after glueing the wheels into their muffs, checking that the motion was working. Actually I found that it was a bit tight and had to thin the slidebars further. The middle and rear crankpins have not yet been trimmed to length, so the temporary "washer" - made from electrical wire sleeving - grazes
antyeates1983

antyeates1983 in scrap tank

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Scrap Tank - painting

It's high time I posted an update on the scrap tank, which is approaching completion. Painting started with a coat of grey Halfords primer from a rattle can. I then used the airbrush to spray the basic green colour all over. I find that Tamiya acrylics spray quite nicely, so I used a mixture of olive green and white, thinned about 50:50 with Tamiya's own thinner. This works for me spraying at about 15 psi (although I don't really trust the gauge on my cheap and cheerful compressor). After painti
antyeates1983

antyeates1983 in scrap tank

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Scrap Tank - new motor

It turns out that the cheap Chinese motors I bought on eBay are just that: cheap. Despite much fiddling with the motor position I couldn't get the original motor to turn the wheels while on the track. The chassis rolled freely with all of the gears and rods attached, but the motor would only turn the wheels if I held the chassis in mid-air, and then only if I held the motor in exactly the right place. On the track, it just wouldn't budge. Eventually I came to the conclusion that the motor just d
antyeates1983

antyeates1983

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Scrap tank - new dome

As I mentioned, I wasn't happy with the over-thick flange on my original dome, so I made a new one using the "squashing on to a tube" technique that worked quite well for the chimney. Here we see the squashing stage in action, after drilling out and thinning the bottom flange.   The resulting dome has a much finer and more realistic flange, as well as a better cylindrical shape, as you can see in the following two comparisons:   Notice that the dome cracked
antyeates1983

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Scrap Tank - mounting the motor

Having said that the next post would be about the coupling rods, this will have to wait as I have been working instead on mounting the motor. I'm using a 7mm diameter coreless one from eBay, which has no built-in way of fixing it in place. So after some pondering I decided to make a collar that can be tightened around the motor to hold it. This started as a length of scrap 0.25mm nickel silver from the sprue of an etched kit. It was easily formed into a circle using a brass bar in the vice with
antyeates1983

antyeates1983

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Scrap Tank - mounting the cylinders

I had previously made the cylinders and motion but not actually mounted them to the chassis. After pondering how to do this for some time, I settled on the idea of a removable unit to mount both cylinders. As you see in the first picture, this is made from a piece of thin PCB, which will be horizontal on top of the chassis block, held in  place by the body fixing screw. At each end I soldered pieces of brass tube that will hold the previously-made cylinders, increasing them to something like the
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Scrap Tank - more details

Next I added some remaining details - the clack valves are impressions made by threading two short lengths of brass tube of 0.6mm and 0.8mm outside diameter onto a length of 0.4mm brass rod. All three of these came in a useful pack from Albion Alloys. They were covered in flux then soldered on with a small amount of solder, before bending the pipe to curve under the boiler.    Fiddlier to make were the next bits, which I **think** are controls for the sandboxes - they sit either
antyeates1983

antyeates1983 in scrap tank

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Scrap Tank - more details

I've continued to add some of the never-ending bits and pieces to my Scrap Tank, and it's about time I recorded the progress. Here are sandboxes (I think that's what they are but wait to be corrected) - filed up from spare chunks of brass with a hole drilled in and a little turned cap soldered in.   And here's one soldered in place next to the smokebox:   In front of and behind the sandboxes, the tops of the locomotive frames (on the real thing) are visible above
antyeates1983

antyeates1983

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Scrap Tank - more bodywork and boiler

Due to a lack of forethought, I found that I hadn't made a large enough hole in the cab rear to accommodate the motor mount. I couldn't get in there with a file so I resorted to a burr in the minidrill to carefully remove the metal. Below you see the body in place on the chassis. If I were to use a similar motor mount in future, I would ensure that it was entirely in the bunker! You can't see it here, but I've also filed down the chassis block so that the body sits at the right height. Thanks to
antyeates1983

antyeates1983

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Scrap Tank - gears and wheels

Here the gears and driven axle are in place in the chassis. The muff is reamed out to be a fairly loose push fit so that I can test the assembly. The wheels will eventually be glued in after painting etc. Some time was spent filing more metal off the chassis block so that nothing was catching. I've also countersunk the heads of the fixing screws here to make them as flush as possible to the side frames, not least because they will be behind the front and rear wheels. The crankpins had been glued
antyeates1983

antyeates1983

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Scrap Tank - footplate

This week's progress has been on the footplate. First step was to cut out a rectangle of 0.8mm (single-sided) PCB, and a slightly larger one of 5 thou brass, and laminate these together with solder. The first photo shows the assembly on the Proxxon with the pattern attached by double-sided tape. I decided to mill out the cut-outs rather than using the piercing saw. I'm not sure this saved any time but it made it easier to get straight edges.   And here is the resulting unit from
antyeates1983

antyeates1983

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Scrap tank - fixing the boiler and smokebox

The next task was to fix the boiler/smokebox assembly to the chassis. Before doing so, I made a chunk of brass to fill the inside of the smokebox saddle, with the aim of giving something to tap a hole into for the chassis fixing screw. I initially intended to make this from insulating material, but didn't have any "engineering plastic" of a large enough size. I tried to make it from a lump of tufnol, but I realised that the space is actually pretty small, so opted to go for brass in the end as s
antyeates1983

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Scrap Tank - drilling the frames

Construction began by preparing two lengths of 15 thou nickel-silver for the coupling rods and two pieces of 0.64mm brass for the frames. In the photo below you see the latter stuck together with double-sided tape.   It is critical to get the holes in the rods the same distance apart as the holes in the frames, so I temporarily soldered the two pieces of nickel-silver together and to one of the frames. (I didn't want to rely on two layers of double-sided tape). In this photo I scribed
antyeates1983

antyeates1983

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Scrap Tank - drawings

During the enforced shutdown I've started work on a loco to shunt my 2mm Diamond Jubilee Challenge entry: a Drummond 0-6-0T "scrap" tank, so called because they were put together by Lochgorm works from leftover bits of earlier engines. I decided to "borrow" the wheels and gears that were earmarked for a Barney 0-6-0. That loco will have an etched body and chassis, for which I have nearly finished the artwork. For a change, I decided that this one would be completely scratchbuilt.   My
antyeates1983

antyeates1983

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Scrap Tank - dome

I made a start on the boiler "furniture" by making the dome. The first problem I faced was not having an accurate drawing of the real thing. This led to me making a first attempt, looking at it sat on the model, and then doing another one with slightly altered dimensions. Although it took some extra time, this did also mean that I had a practice run to work out my method.   I started with some 8mm brass rod (annoyingly, the widest part of the flange was estimated to be a little more th
antyeates1983

antyeates1983

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Scrap Tank - cylinders

Today I made the cylinders. Rummaging through my brass stock I found two concentric tubes, one whose inside diameter was a nice sliding fit on the 0.5mm piston rods, and another that fitted around it and had 2mm outside diameter. These two tubes will allow me to make a (coarse) representation of the housing/bearing where the piston rod enters. I had calculated that the whole thing needed to be about 4mm diameter, allowing 0.25mm for an outer wrapper (looking at prototype photos, it look like thi
antyeates1983

antyeates1983

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Scrap Tank - coupling rods

Having drilled the rods (15 thou nickel silver) at an earlier stage, I then shaped them while still soldered together. For this I stuck on the template with double-sided tape, cut roughly to shape with the piercing saw, then began a reasonably laborious process of filing to shape. Always being very careful not to remove too much material! I find the most useful files for this are a triangular one (to get into sharp corners) and a flat one with one "blind" edge. I held them in the vice for doing
antyeates1983

antyeates1983

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Scrap Tank - chimney

Apologies for the lack of updates recently. I've continued to make progress but not got around to writing it up. The next thing to be tackled was the chimney. Again I made a rough sketch guessing the dimensions from photos and Peter Tatlow's drawing. Since the chimney has a very thin skirt around the base, I decided to adopt the "squashing" method instead of the "filing" method used with the dome. In particular, I first drilled a hole up the middle of the chimney, then cut the top of the flange
antyeates1983

antyeates1983

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Scrap Tank - cab roof

Next step was the cab roof. This is made from a piece of 10 thou nickel silver, from the waste area around a sheet of etches. This was formed to the curve by bending around a brass rod, tweaking it until it matched up to the cab front and rear profiles. It is not fully curved and should be horizontal for a bit at the sides. I achieved these flat sections by clamping it in the vice and bending with a steel rule.   For the raised beading around the edges, I soldered on lengths of 0.3mm n
antyeates1983

antyeates1983

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Scrap Tank - cab details

Hopefully I won't disappoint anyone if I reveal that I don't mean interior details. Rather, I've added the spectacle plates, beading and vertical handrails on the outside of the cab.   For the spectacles I made use of the etch I made previously for the Banking Tank. I already had a spare copy from which I had "borrowed" some other part during construction, so I thought I would make use of this. On the Banking Tank, the spectacles were part of half-etched overlays for the cab front and
antyeates1983

antyeates1983

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