Cranks, Rollers and Rods………

     Towards the end of 2019 I started to gather as much information as possible, along with the components that I would need to model the point rodding, and facing point locks (FPL’s) for Bleddfa Road. Steve Halls articles on the subject in the Model Railway Journal No’s 113 and 115 were particularly useful, and Russ Elliot’s account of modelling the point rodding for ‘Green Street’ was another excellent source of information. To begin with I soldered up a few cranks and other etched components to get an idea of their size, and as an aid to planning the rodding runs.  Styrene bases for the rollers were laid in place, the track was ballasted and then I became sidetracked with other projects. In the meantime I had bought a copy of Laurie Adams  excellent book on the subject, though published by the 2mm Scale Association they will happily sell you a copy whether you are a member or not. The book contains many useful photos of prototype installations, along with numerous diagrams so it is well worth purchasing a copy.

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On the prototype the rods aren’t square but of an inverted ‘U’ section, something that is, to the best of my knowledge unavailable in the size required for 7mm scale rods. For those who can’t accept having to compromise then the correct size round rod, with rollers to match is available.

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Though the larger 7mm scale components are easier to handle, it is still a fiddly time consuming job to assemble and install them. When preparing etched components I find it easier enlarge any holes whilst the parts are still attached to the fret. So each hole was gently opened up as required with a broach, the components were then removed from the fret, dressed with a file and soldered up. The Downset drives were a bit of a problem as they are of round section, and have to be joined to the square rods. I ended up making them from 0.33mm brass wire which is a tad too small. The trouble is anything larger is out of proportion to the cranks. Those more skilled than myself would probably be able to make them true to the prototype with forked joints. But to quote a well known film star, “a man has to know his limitations”, and I’m discovering more of mine as I grow older. The length of each rod was calculated and the downset drives soldered in place as per the photo above. But rather than chemically blacken them I used a permanent marker pen as suggested by that well known painting and weathering guru Martin Welch. These days I am becoming rather sensitive to the fumes of the solvents, and chemicals that we modellers use, and yes I do wear a face mask. So I have started to safely disposed of certain fluxes, metal blacks, solvents and paints. Much to my surprise the marker pen has worked really well, the treated surfaces taking enamel and acrylic paints without problem.

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Looking back I wonder how on earth I managed to assemble and install the 4mm scale point rodding on Llangunllo.

I started off by installing the cranks and compensators on their bases. Rollers were threaded onto the prepared rods which were then laid in place. To be honest I had been dreading the whole job, but once I saw the first section of rodding taking shape on the layout I began to enjoy myself. I think that is typical of those boring jobs like ballasting, that are so easy to talk yourself out of doing. Yet when you make a start you begin to wonder what all the fuss was about.

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The first section to be installed ran from the ground frame down to the quarry branch trap point. The run called for two cranks to transfer the rodding under the track to the siding loop and a single compensator. I was expecting the various 7mm components to be larger than they actually are. Take the rods for example they are only 0.7mm square, slightly smaller than those produced by Wills for 4mm scale! The same applies to the rollers which are again smaller than the Wills mouldings.

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Care had to be taken to ensure that the rods didn’t cause any short circuits where they passed under the track. A quick check with a feeler gauge revealed a 12 thou gap between rail and rod. But to be on the safe side I attached slivers of styrene strip to the top of the rods, where they passed under each rail with a drop of cyano.  I did consider using plastic rod but had none of a suitable diameter in stock, and so to the other side of the track…….

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With its two compensators and cranks this section of rodding was the most difficult to assemble and install. But from then on the rest of the installation was plain sailing. Having studied no end of photos the colour of the rods tend to vary from light grey through to different shades of dull black, where they pass through the rollers and rust where they don’t. Cranks and other moving parts that are oiled and greased were painted in metacote gunmetal enamel, which captures  the look of lubricated or greased metal when gently polished up with a cotton bud. Roller frames tend to be a rust colour, at least on branch lines. So my rodding has been painted with different mixes of Humbrol gunmetal, light earth and Precision Paints dull red. The last mentioned being mixed to create different shades of rust. Finally a light dusting of rust weathering powders provided a little texture. As usual the best thing to do is to study the prototype for ideas.

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The last pieces of the jigsaw were the two facing point locks (FPL’s), had I stuck to my original idea of modelling a freight only line then I could have made things easier for myself, for no FPL’s would have been required.  Once again I turned to my many railway albums for information, ‘GWR Branch Line Termini’ by Paul Karau proving particularly useful. There are also several colour photos and a selection of diagrams within Lawrie Adams book, which show the locks in detail, and the method of securing their cover plates. So using those as a guide I guesstimated the size of the things and came up with this…………

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The actual locks were made up from styrene and brass section, and will mainly be hidden from view once the covers have been installed. So why go to the trouble of attempting to model them? Well I have learned that there is no hiding place in 7mm scale, and from certain camera angles the missing lock assembly would stick out like a sore thumb. There should be a guide or two attached to the sleepers to support the actuating rod and various brackets to which the cover plates are bolted.

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This is the first of two (FPL) cover plates, according to the information that I have the GWR cover plate was 9ft long, the two ramps being 2ft – 2 inches long. I made both plates, the supports and bolt heads  from styrene. The covers were painted with my old friend Humbrol metacote gunmetal, rust weathering powders were then applied whilst the paint was still tacky. Once dry the gunmetal was buffed up with a cotton bud to produce a slight sheen.

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A helicopter view of the rodding prior to installing the (FPL) cover plates. I made a mistake when calculating the length of the point locking bars, so ended up reworking them. Such are the perils of working from photos. Those unsightly rectangles of white styrene, onto which the rollers have since been attached have been trimmed to size, painted and the ballast made good. That alone makes a huge difference to the appearance of the track bed.

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Whilst not perfect I am happy with how things have worked out, and can now press on with the scenery, backscene and buildings. As usual I will be experimenting with different  ideas as I try to create a model of a railway.

Geoff.

 

8 thoughts on “Cranks, Rollers and Rods………

  1. That rodding looks great. Well done.
    For information. The channel section rodding was galvanised steel. If you go back to earlier times point rodding was round in section.

    Liked by 1 person

    1. Thank you,

      Going back even further the round rodding was actually made from old gas pipes before being replaced with a solid section! Lot of interesting info. in that little book that I mentioned, and no I’m not on commission 🙂

      Geoff

      Like

  2. Thank you for writing and sharing your photos. Your research is always interesting and I always admire your workmanship. You are an inspiration.

    Liked by 2 people

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