7mm At the Western End of F7

Discussion in 'WR Action' started by SimonT, 17 December 2013.

  1. Scale7JB

    Scale7JB Western Thunderer

    Hmmm not sure about the RSU on this one.. It's awfully thin brass on the boiler, and the 'T' section is usually quite a thick gauge. It 'could' make the bow in the cladding even worse..

  2. Steph Dale

    Steph Dale Western Thunderer

    It would also mean that you couldn't use the joiner/cleats piece, which does make life so easy.

  3. Ian@StEnochs

    Ian@StEnochs Western Thunderer

    The beauty of the rigidity of the Tee section is that it keeps the thin etch in line. I would not consider using an RSU here. A conventional iron works fine and, in combination with a wooden 'presser' to keep both sides in contact, does permit local solder softening on both sides of the joint at the same time.

    I should have said that I usually tack solder the two ends before randomly seaming between until the whole joint is completed.

  4. SimonT

    SimonT Western Thunderer

    Thanks for the various bits of advice chaps. As I said at the beginning, the aim of this build is to do it as it comes out of the box to provide photos for the instructions. There are loads of mods on the list already but I am resisting the temptation to implement them.

    I don't much use the RSU but it does have the advantage of controlling the amount of energy in (the tranformer tap in use and the the time of current flow). An iron just feeds energy in which the brass convects away to expand the brass until the local temperature is high enough to melt the solder. A main reson why I dislike building in brass but have no alternative here. So, I am examing the options. I will report back in due course. I also have two pieces to work on as the smokebox is in the same state.

  5. Steph Dale

    Steph Dale Western Thunderer

    The thermal expansion of brass compared to other materials we're likely to be using is illusory, it's pretty much identical for nickel silver*. Metalurgically they're exceedingly similar...

    *Of course, you might be thinking of another material; whitemetal does have a much lower expansion rate.

  6. SimonT

    SimonT Western Thunderer

    While I hear your arguements Mighty Engineer, the point is that you can put less heat into soldering together two thin bits of material by selective use of appropriate RSU delivered energy than you can by holding the Mother of All Soldering Irons (MOASI just doesn't have the 'street' of MOAB) to the metal for a while. Think spot welding rather than seam.
    And I still dislike brass:p
  7. Steph Dale

    Steph Dale Western Thunderer

    Tis true, actually I agree with your last post - but I've never had a problem with brass...

  8. Yorkshire Dave

    Yorkshire Dave Western Thunderer

    Misleading title - and I thought you might be building a Denver and Rio Grande Western F7. :p ;)
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  9. SimonT

    SimonT Western Thunderer

    Some more progress to show. The frames are a simple tab and slot assembly that goes togther very easily.

    The hornblocks were fitted using my Avonside jig as I haven't any graph paper to try out Martin's suggestion of fixing the first hornblock in place before assembling the frames, and then using 3/16" rod and springs to set the hornblocks square over the graph paper. I'm sure it would work. My purchased brass 3/16" axles with the tapered ends were retired to the scap box when the jig arrived and one has already been recyled on the lathe to another use!

    Next bits of work were the compensation gubbins and then the overlays to give....
    All remakably straight forward other than my not folding the valve gear rocker pivots down at right angles and then re-inforcing them with some solder. For some reason I got it into my mind that the holes are set above the frames like the real ones. They are not and of course I caught one while doing some work underneath. Yes it eventually fell off and left me with the problem of setting it at the correct height. Bum!

    Cylinders next.

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  10. SimonT

    SimonT Western Thunderer

    It has been a while since I posted any photos of progress on the Hall. Mostly I have been doing lots of other writing and some building in the spaces in between. This post will jump through at a resonably rapid pace. As you can see I have been trying to use the Quantum solder developed by Richard.

    So here are the cylinders about half way through the build. As you can see it is all etches and tube and it is a joy to build as everything fits first time. My only reserve is that to my perception it is all a bit like a fashion model - stunning to look at but a bit under nourished.

    Here they are finished. The only three hand job were the drain cock levers where a lump of Blue Tac serves to stop the cylinder going walk about while one hand hods the tweezers and the lever and the other hand holds the iron for a quick in and out with a micro bit of solder on the end.
    DSC00451 (2).JPG

    Having finished the cylinders it was on to the brakes. All reasonably straight forward to build on the chassis with the wheels in place. As this is a straight from the box build I have stayed with the brass brake hangers and shoes. If it were a build for myself I would be using 3D printed hangers and shoes to get the bulk, especially down the bottom, and also to get insulation and thus close setting to the wheels. And yes, I have done moving brake shoes. DSC00479 (2).jpg

    While we are on chassis bits, here is the inside motion.
    As you can see, I have made conspicuous use of metal black to stop things soldering up. I find the small rivets difficult to get on with. Sometime peining them works and some times I find myself adding solder to the joint to make it hold. The suspension link on the right, that is hanging upside down, is held on a piece of rod with a 16BA washer to keep the link in place. The eccentrics were soldered in place using my micro flame jobbie. It worked a treat.

    Next will be the footplate and other upper bits. I need to push on to get it finished to be on the stand at Telford. I just need to find a 4000G tender for it....

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  11. SimonT

    SimonT Western Thunderer

    I realise that there has been a 'bit' of a gap in posting progress on this jobbie. Might I plead too busy building the thing for Telford and documenting it into the instructions? Progress has been rapid and I will cover the ground here at a fast trot; a phrase acquired from the Present Mrs and Miss T who in return are able to use the word backhead.

    First the footplate. Well, it goes together easily as you would expect. Not shown is the wooden buck that I make for each loco that I build to support the footplate; it was a technique used by Guy Williams. DSC00520 (2).JPG

    So the next main job is the firebox. This consists of some thick plates that form the front and rear and an etch that forms the outer skin of the firebox. Martin suggest using some spacers such as the ones he used. Not having Martin's spacers I tried several techniques such as two lengths of 4mm studding and a load of nuts to space and lock (wouldn't stay square when touched) and then turned up some spacers from some rod in the spare metal box. The set up is shown below.
    This method is under review as we would like to come up with an easier method. The large diameter of the lower spacer was taken care of by using a couple of parallel slips to raise it off the surface that I trued the assembly from; I have a small surface plate but a lathe bed, piece of glass or even a new flat piece of tufnell will do to provide a flat, level surface to set the ends flat, true and parallel.

    Now, progress in the form of the skin on and the inside of the front edge of the firebox filled with plumbers solder to build up the inside of the front edge of the firebox.
    To get the front formed correctly, work down in the size and fierceness of the cutting/polishing tools and keep moving the firebox around so that you see the work from all angles and above all, have a couple of clear photos of the real thing in front of you - the top corner has a big radius. Other than that, everything else in the photo is routine.

    Finally, for today, forming the boiler. Mine was already partially rolled however, I did do some work to try to get the curve to continue to the ends. The set up for soldering is as shown below. The joining piece and the inside of the boiler were tinned and then assembled into the following set up. Then it was in with the iron set to v hot and hold things down with an old lolly stick. Here is my set up; if you don't have V blocks I'm sure a couple of books or some scrap wood with some V's cut in would do the job.

    The brilliant thing about Martin's design is that when you put the end formers into the cone it goes to the correct shape and becomes rigid. So, finally for now, here is the coned part of the boiler looking bright and shiney.
    Those who were at Telford might have seen the finished model in grey primer, so there is more to repot. Luckily a 4000 gallon tender has been found and I am well on with that build and photography. I'll try to catch up here - honest!

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  12. SimonT

    SimonT Western Thunderer

    It’s all been a bit quiet here, not helped by a house move after 32 years in the same place. The involvement of four horses, about six tons of wood and MissT made for interesting times.
    Anyway, down at the prototype shed, the proof of concept build to meet a request from some of you Swindon fans is coming along nicely. It will be on the table at Reading, providing that I remember to pack it!
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  13. SimonT

    SimonT Western Thunderer

    Evidence of progress on the God's Wonderful front. So, what comes next?
    A very Merry Christmas to you all.

    PS Supplementary Question. What song would provide a background to this little thread?
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  14. daifly

    daifly Western Thunderer

    What comes next? The locomotive to tow the tender perhaps?
    Song? The theme from Rawhide - that was a great western series!
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  15. Phil O

    Phil O Western Thunderer

    Hi All

    I have just read this thread over the Christmas period, some very useful tips and information. I would add, that those of you using RSU's should try their local welding supplier for Carbon rods, they are quite a bit cheaper than the modelling suppliers, in fact when I went to get some more, about this time last year, I had the last two in the store for free.

  16. SimonT

    SimonT Western Thunderer

    Continuing the theme of a very long build with bits coming out of the factory one at a time, an early narrow footplate coal rail tender with front sandboxes and a low footplate has become a late coal rail tender with repositioned sandboxes, medium height raised footplate and separate pick-up dome and water filler. It also has the fire iron storage and different tool boxes and wide handrails.

    This is, of course, a build to provide photos for the instructions to describe the myriad variations of these tenders. The chassis is different on each side. The requirement for the early narrow handrails and the fitting of the wide hand rails resulted in the set up shown below as I lost the bit of footplate I had fretted off.
    The model will be on the stand at Bristol and hopefully the boxes will be with us soon.

    Loco to tow it - tick!
    Music? Johnny Cash and something about a Cadilac!