7mm On Heather's Workbench - a baby Small Prairie

Discussion in 'WR Action' started by Heather Kay, 2 August 2017.

  1. Ian@StEnochs

    Ian@StEnochs Western Thunderer

     
  2. Heather Kay

    Heather Kay Western Thunderer

    Thanks Ian. I may still revert to the etched rods - assuming they will fit without major upheaval. I'm still considering some metalworking to thin the milled rods, but it may well be more work that necessary.

    Today, basic brake rigging and pony trucks!
     
  3. Heather Kay

    Heather Kay Western Thunderer

    Today, pony trucks … and brake rigging possibly!

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    The JLTRT super detail kit was added to the box. As this was designed to match the Mitchell kits when they were taken into the JLTRT stable, fitting is not a problem. Making up the pony trucks was an exercise in careful filing and finger-singeing. I used the axle to try and keep things square, which more or less worked. I rather like the pivot fitting, which is a spigot that pokes through the spacer hole, the truck held by a split pin. I've used some brass wire for testing, until I'm ready for a more permanent fixing.

    Inevitably, one of those compromises arises. Being designed for O Fine, the truck castings are a smidge narrow. The rail guards are cast as part of the truck sideframes, and need to be carefully - very carefully, since the alloy used in this set is very soft - bent to align with the wheels. With the wider gauge, the guards may not be long enough to be close to the rail after bending. I think I shall repurpose the guards on the etched parts for the pony trucks.

    The cast pony trucks aren't quite right for the early form, at least as far as comparison with the drawings is concerned. They do match the etched ones, so I guess I'd have been stuck either way!

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    The front truck has the pivot set back further than the rear. I understand the rear pivot point was "adjusted" to allow clearance for fitting drive mechanisms to the rear axle.

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    Here's the rear pony. The guard irons appear to stick out below where the buffer plank will be. At this stage, I haven't fixed the pivot pin in place, and it's allowing a bit of slop in the fitting. It may be I need to file the pivot hole a little to move it further forward a bit. That may have to wait until I've started the bodywork so I can see how it all fits together.

    I've been whizzing the chassis up and down the test plank, and it rolls quite sweetly, even without any springs installed as yet. With the trucks in place, the frames begin to look the part.

    Right, am I in the mood for brake rigging? Not really, but I'll compare parts with the drawings and instructions for now.
     
  4. Heather Kay

    Heather Kay Western Thunderer

    This week has turned out a little sporadic, thanks to my regular osteopathic treatment yesterday, and domestic duties today. Yesterday evening, though, I turned my attention to the upperworks.

    As originally built, these little locos had a snubby snout, with little smokebox protruding from the saddle. They also featured a straight and square frame drop to the front. Both these features are catered for in the kit, as well as the shorter bunker and associated clobber.

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    The client had reminded me about the smokebox issue, and someone in the past had drawn a pencil line effectively shortening the smokebox wrapper. You can see it in this shot, just inside the row of rivets around the front of the box.

    I wasn't entirely convinced, so I spent a while poring over the drawings. Happily, one of the prints I'd made scaled at pretty much dead on 2mm to the inch, so I permitted myself the cardinal sin of taking a measurement from it. The drawing informed me the smokebox was 4ft long, inside, but I wanted a slightly longer datum to work with. I chose the front of the side tanks, since there is a cut out in the etch which coincides with this point in the model. After some brain cell action - advanced maths is not my thing, so it took a while - I worked out the distance from the tank front to the smokebox front was 6ft 7in. The etch scales spot on.

    So, Malcolm had apparently designed the smokebox etch to be correct for the earliest versions of the locos. To represent the rebuilds with the superheated boilers, the model builder is provided with a whitemetal cast ring that fits over the front. Obviously, such things aren't explicitly stated in the instructions, so I had my epiphany as I nodded off to sleep last night! Now I come to consider it again, I shall go over my calculations before I decide that things are hunky dory and commit to construction.

    I decided it was sensible, having got the chassis so far, to attack building the bodywork to enable checks for clearances, motor mounting and so on.

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    This is where I got to in today's truncated session. What's not obvious here is the sections removed at the back end for the shorter bunkers. It's always a worry, chopping chunks off things, even if they're designed that way. I checked the text and drawings a couple of times, compared the fit over the frames, and eventually wielded the shears. I hope I was right! With the running plate frame bent up, the overlay went on, and I was about to install the front dropped plate section…

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    Oh dear. Can you spot the problem? Let me explain: early locos didn't sport those characteristic GWR struts at the front. They came later on. The half-etch has the mounting brackets. That's not something I can grind away and not leave a mark. There are also handrail knob holes that will require filling, and the lamp brackets will be replaced with cast items… It seemed a good time to down tools, and let the idea of making a replacement front deck roll around the old noggin for a while.
     
  5. OzzyO

    OzzyO Western Thunderer

    Hello Heather,

    just a couple of points/questions, I'm a bit surprised that you did not use the cast horn guides / axle boxes.
    On the pony's I'd check the wheelbase from the front and rear drivers to the pony wheels, I had to move the pivot centre on one of them as seen below.
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    ATB

    OzzyO.
     
    Michael Osborne likes this.
  6. 3 LINK

    3 LINK Western Thunderer

    Good evening Heather,

    If you are considering going down the route of a new front deck, then surely you have nothing to lose by attempting to maybe grind away the raised parts of the etch with a Dremel or something similar, and then any filling can be done using solder.

    Just a thought,

    Martyn.
     
  7. Heather Kay

    Heather Kay Western Thunderer

    Hi Paul! It's nice seeing you about the place again! :thumbs:

    I haven't actually chopped the guards off yet. What I shall probably do is bend them up as required and see if they sit a suitable distance from the rail head while being in line with the wheels. This is a ScaleSeven build, so the wheels are a bit further apart than for O Fine. If I find things don't pan out - and the brass is very soft and easily bent, even by a derailment during testing: ask me how I know this! - I shall adapt the etched ones. They'll be stronger as well.
     
  8. Heather Kay

    Heather Kay Western Thunderer

    ''Tis a thought. I might try that anyway, but I have previous in this and the results have never been satisfactory. Lessons learned, and all that.

    In any case, I'm not entirely convinced by the raised panel lines. I'm pretty sure they should be engraved, but have ended up raised for production reasons. If I can get my riveting in straight lines, making a new plate from scratch really won't take long. I also have to make a new cab roof, as the ventilator is etched as for the later rebuilds. The original builds had a wooden roof with the vent offset to the driver's side.

    I don't half pick 'em!
     
    Rob Pulham and 3 LINK like this.
  9. Heather Kay

    Heather Kay Western Thunderer

    First, bear in mind this isn't the JLTRT version of the kit. Although there are cast hornguides in the box, and I originally intended to use them, they were taking far too long to separate from the runners and clean up. The two I did clean up then didn't even fit the opened slots in the frames! So, I went back to the etched parts that were designed for the job.

    As most of the inside frames detail will be all but invisible, I am happy with the way things have worked out.
     
  10. From the limited number of photographs I have, mainly of 3104 at South Brent it would appear that the front plate is 'plain' presumably flush riveted. Does your information/photo's suggest the same? With any luck it will only require a replacement square piece of brass. Hope this helps.

    Malcolm
     
    Heather Kay likes this.
  11. Heather Kay

    Heather Kay Western Thunderer

    I'll have a good look tomorrow. If that proves to be the case, that will be good shortcut!
     
  12. Heather Kay

    Heather Kay Western Thunderer

    In the cold light of day, I have been peering at the few clear photos of these early locos. I can now see, in views of 3102 and 3104, that the front deck appears smooth - perhaps parallel rows running across the frame either side of the pony truck spring housing - as does the running plate over the cylinders.

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    I am pretty convinced by this. Some of the locos appear to have retained this feature through rebuilding, while others appear to have acquired a mess of rivet pimples. I'm building 3107, and of course don't have any photo records of that particular loco, so whatever happens it'll be a hybrid of 3102 and 3104!

    Note, also, the lack of front deck steps. I think I will need to source a several dinner services worth of pepperpot lubricators too! 3104 (the lower photo) shows two lubricator pots over the cylinder, while 3102 above it doesn't have them. Both sport pots on the motion plate.

    One other problem I will need to deal with is the etched part for the coned section of boiler has location runs for the top feed pipework - and guess what I'm not fitting to this build? One option will be to invert the etch and replicate the bands and washout plugs on the reverse.

    I do like a challenge!
     
  13. OzzyO

    OzzyO Western Thunderer

    Hello Heather,

    have you checked the wheel base from the front driver to the front pony wheel and the same at the rear?

    ATB

    OzzyO.
     
  14. Heather Kay

    Heather Kay Western Thunderer

    Not yet. I will, though, as I haven't permanently fitted the pivots yet. :thumbs:
     
  15. Heather Kay

    Heather Kay Western Thunderer

    After my post earlier, I had a call from the ever-helpful Basingstoke GWR Research Department. An enjoyable and educational chat ensued, which clarified a number of interesting points.

    With no further evidence than the photos of 3104 at Brent, we've settled that particular loco appears to be oddly and subtly different in some aspects to the main production batch. The extra lubricators over the cylinders, for example, appear to be unique to 3104. On that basis, I'm not going to fit them. The lack of visible riveting seems to be correct for most of the 10 production locos - countersunk rivets being a thing back then - then, at some point during rebuilds before the 1914-18 war it seems to have changed to "normal" riveting.

    On that basis, I've elected to clean back all the etched riveting on the front part of the loco. That's made fabricating the replacement front deck even simpler - aided by photographic evidence that the deck was apparently a single sheet of metal, and not made of various sheets as implied by the kit part. More simplification.

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    With all the foregoing, here is what I've done. You will note some ghosts of the original half-etched rivets on the running plate. I've decided not to fret over them, as even countersunk rivets would be visible, and I'm sure a coat of primer and paint will lose them. Checking with the photos, the front deck was not radiused on the corners. I've marked where lamp brackets and the spring cover will go, but that's it for the front deck. I can now move on with other parts.

    Phew!
     
  16. Heather Kay

    Heather Kay Western Thunderer

    I was going quite well at the end of last week. The running plate was coming along nicely. I had made up and fitted the front buffer plank, and was working my way along the hanging bar (valence for us non-Swindon types) overlays on the driver's side - when I hit something of a snag.

    As these little locos were rebuilt and modified, the bunkers grew, and to allow this to happen the rear buffer plank was shifted out, packed with timber. You can spot this quite readily on the 4400 class later in life. As this model is of the original small bunker form, several sections of running plate and frames are set out for removal. I followed the words, and the marks, in each case, but something went awry. Not paying attention quite as I should have been, as I was on a roll, it wasn't until I was about to fit the rear buffer plank that I spotted the problem.

    I let the problem roll around the braincell for the weekend, got engrossed in completing another build which overran into Monday, lost Tuesday to a bout of the misgogs, Wednesday to some domestic stuff and a bout of lurgy, so it wasn't until later on Thursday I got back to it.

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    The instructions suggest the buffer plank should be fitted up against the rear of the hanging bar under the cab. I merrily assumed this would be the case and trimmed and fitted the valence overlays. Test fitting the beam revealed there was a huge overhang on the running plate. That couldn't be right, and sure enough photos show the beam virtually flush with the end of the running plate. At first, I wondered if there was a dimensional error, and once I'd worked out the total loco length and found it matched pretty well to the running plate, I could sort things out.

    You can see here the frames are a good chunk shorter than they could be. This was annoying, but not something that's insurmountable later.

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    Knowing the running plate was the right size, the answer was to use a bit of brass angle to support the buffer plank in the right place. From there, the valence overlays could be trimmed and fitted correctly. The overlays are made of three parts. Again, the kit caters for later variants with a curved drop front, as well as the squared version I'm building, a main section and the rear section which must be trimmed to fit.

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    That's pretty much the overhang I wanted to see!

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    Again, the frames are short. What I'll do is make up a plate to fill the gap at a later stage.

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    With the buffer planks and hanging bars sorted out, I could at last begin to build upwards. So far, the bunker and tank sub-frames have been formed up and fitted.

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    Remember I said I'd trimmed the valence overlay before I'd realised my error? Luckily I hadn't discarded the bit I'd chopped off. I've made the best fit I can, and hopefully a smear of filler and a quick going over with a sanding stick will hide the joins.

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    On the other side you can see how the overlays work. Again, there's a join to hide properly later. Obviously, in later life, all manner of pipes and conduits were run along the outside of the valences, but I don't have that luxury on this build.

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    This is how the join under the bunker should look!

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    Finally, with the smokebox saddle formed up and fitted.

    Having got back into the swing after an odd week, I find I am now needed elsewhere for Friday and Saturday. So, I shall return to the workbench on Sunday, with a view to building up the cab and tank overlays.
     
    Last edited: 17 August 2017
  17. Heather Kay

    Heather Kay Western Thunderer

    Our story had been left with the basic tank, cab and bunker formers in place. Sticking with the instructions' sequence, give or take the odd diversion, here's where I got to today.

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    Cab front and back sheets go in. Aided by my small engineer's square (that's a small square, not a square owned by a small engineer, obviously!) and a magnet, I could support the sheets vertically in their slots while some solder was dabbed on to hold them in place. The back sheet has a half-etched overlay which was sweated on. The design allows for the coal doors to be cut out and fitted in an open position. The downside is I'll need to make up some doors and latch mechanism to go on the inside. Swings and roundabouts, I guess.

    There are no window frames in the kit, so I'm not sure how the front spectacles will work. I may dig into a 4500 kit I have in stock for another client to see if there are parts in the JLTRT version. Amazingly, I do have some brass tube of almost exactly the right diameter for the front portholes. I'm thinking of making something that will allow the porthole to be fitted in the flipped open position.

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    For the earliest form, the rear spectacles were not protected by wire guards. You can't see, but the tank sides inside the cab have been fitted, and some thoughts have been bent towards what cab details can be fitted at this stage. Sadly, there's a half-etch strip under the windows. This is meant to take a rivet strip, but the original builds didn't have this feature. There's no sensible way to remove the strip, so I've elected to ignore it and simply not attach the riveted bit.

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    Time to think about cleaning up and forming the tank and cab sides. The basic etch is for the later rebuilt largest bunker versions of these locos, which Malcolm obviously felt might be the more popular for builders. Alternative bunker sides and ends are provided, including the one for the original build. At some point I must pluck up the courage to actually make the cut at the top of the cab opening. My worry is making the joint clean so it's not going to be visible. I've chickened out for today!

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    Here I've plonked the short bunker end over the main etch which, if nothing else, serves to show just how the characteristic GWR bunker shape evolved as the capacity increased. Alternative handrail location holes are etched through, so I've got to find some way to satisfactorily fill a few up without losing the half-etched riveting. I've arrowed the holes I need.

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    Having run out of steam today, here's the state of play. The tanks have been formed, flattened and reformed because I got it wrong the first time to give as neat a fit as possible round the front. I found I needed to trim a smidge off the edges where they meet in the middle front. This area is obscured by motion plate and boiler, so the join doesn't need to be invisible, but I've tried to make it as neat as possible. I've posed the side sheets, still with their bigger bustles at this stage. It's all taking shape nicely.

    Another chore will be how to form the minuscule flare on the bunker back. I have a cunning plan, but if it goes spoggly it won't take long to make up a new sheet from scratch.
     
  18. john lewsey

    john lewsey Western Thunderer

    Superb as always
     
  19. Heather Kay

    Heather Kay Western Thunderer

    Hmm, it too sure about that. I think "adequately good" might be better! ;)

    A bit of a bumper piccie crop today. It was time to tackle trimming and fitting the cab and tank sheets. Before that, though, something that had nagged at me. I'm in the habit, at the end of a session, to look over the day's work and contemplate the reference materials. For a while, the front end had nagged at me. On the real thing, you can just make out little crescents that are the valve chest covers, just poking over the front platform on the drop sheet.

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    This is the overhang I had of the main running plate. Comparing it to photos, it was hanging over too far, and would make it a right pain to fit the crescents later - not that such parts are in the kit, of course. I think I have full cast fronts, which won't fit or be visible if things go to plan. Anyway, how to shave a bit off something already assembled without causing excessive damage to everything else…

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    First, I applied three layers of masking tape to the lower deck. I scribed a line just a bit further back from the leading edge of the running plate. Then I set about with quite large files, working carefully along the edge in one stroke. The tape was there to let the files slide along without marking this area.

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    Well, that's a lot better. Pleased with that, mainly because I'd worked out how not to damage previous work, and it was a success!

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    As the tank front bends had already been formed up in yesterday's session, it was time to trim the large bunkers off, and then attach the tank side overlays.

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    It all went rather too well. Rather than attempt to sweat the whole thing in place, which really wouldn't be practical to be honest, I followed the instructions and used the holes provided in the substructure to apply dabs of solder in strategic places.

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    With heart in mouth, I carefully trimmed and fitted the new bunker sides. The tops of the cab are very vulnerable and need to make a butt joint, so I reinforced the backs with suitable strip. It's solid as a battleship now. You can see the joins, unfortunately, and the etched parts don't quite line up accurately - however, I note the original wooden roofs had small angle strip along the outer tops of the cabs, so that'll help disguise joins and mismatches.

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    The front end of the tanks. It took a couple of goes at getting the second side in and lined up. I'm not worried about solder showing, as it's behind the motion plate.

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    My plan for the flared bunker back plate worked. Once the sides were in place, I could mark where the flare began. Some playful gas flame work allowed the flare to be gently formed over a rod of suitable diameter. I got it more or less right at the first attempt! Yes, I was a bit shocked as well.

    I trimmed the substructure at an angle. Where it would be invisible with a larger bunker, it would be harder to hide on this version, even with a full load of coal.

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    Not looking too bad. After a couple of dry fits, I decided to gently bend the edges of the end plate to make a start on the radiused corner. Without a clear idea of how the flare and radius would work, I left it to resolve itself as I worked on the corners themselves.

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    Some time later, and with the rivet strips fitted along the bottom edge, it's all beginning to look the part. I may get a chance to fit the beading strips along the top edges later.

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    I had been worrying about this part of the build, but it's turned out quite well. I think I'll give up now, while I'm ahead!
     
    Last edited: 22 August 2017
  20. john lewsey

    john lewsey Western Thunderer

    Heather you're work is excellent you make some lovely models
    John