7mm Mickoo's Workbench -WS 72xx - MoK Urie King Arthur - JM LMS Garratt

Discussion in 'Area 51' started by mickoo, 8 September 2018.

  1. Yorkshire Dave

    Yorkshire Dave Western Thunderer

    The water from the dehumidifier should work as it is moisture taken from the atmosphere i.e. rainwater which is naturally softer.

    Unlike tapwater which contains dissolved minerals collected during it's percolation through the geology to the aquifer.
     
  2. SimonT

    SimonT Western Thunderer

    Yup, and a load of 3D work;). Swindon Frame plan and sections that can be any size you want in your drawing app. The frames are 'interesting'.

    I used to run a marine aquarium and once tried to use water from a dehumidifier to save the faff of going to collect reverse osmosis water. My tank chemistry went wild. Talking to the chap at the shop, who knew way more than me, I discovered that dehumidifier water collects metalic ions and god knows what during the freeze/melt cycle and is a strict no-no for aquariums. Just to be aware, it might bring a new problem. RO water is pure and not at all expensive from your nearest fish shop. The tank that you buy while in the shop and the corals, fish, etc, etc....:D

    Simon
     
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  3. simond

    simond Western Thunderer

    none at all, I’d hope!
     
  4. Focalplane

    Focalplane Western Thunderer

    Melted ice, particularly from glaciers and ice sheets, can be very pure. So if you model in Greenland. . . .

    Where I grew up we had a well under the kitchen floor but when it came to washing hair, we used the third tap over the kitchen sink which was fed from rain water gathered in a tank below the guttering. It was disconnected when Welsh water finally arrived from Birmingham, supposedly an improvement but at a cost!
     
  5. 3 LINK

    3 LINK Western Thunderer

    Crumbs that sounds ominous, who’s kit is this ?

    Martyn.
     
  6. adrian

    adrian Flying Squad

    From the description I'd hazard a guess at Warren Shephard.
     
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  7. Deano747

    Deano747 Western Thunderer

    I agree with Adrian. (WS in the title) I have a 51xx of his breed to build at some stage. Same with the tank sides and riveting through a paper overlay.
    GW rivet tool will earn its worth, I feel!!

    Regards, Rob.
     
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  8. Focalplane

    Focalplane Western Thunderer

    Me too with Warren’s GW mogul. Lovely brass castings in the kit.
     
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  9. mickoo

    mickoo Western Thunderer

    Y'all correct chaps, a Warren Shephard 72xx, to be fair the GW rivet tool isn't going to work I'm afraid.

    I did some test rivets on the carrier etch, it barely dented it, there's no half etch indent on the rear so you're effectively trying to punch full thickness 0.7 mm brass, it ain't having it, not unless you're prepared to stand on the lever, run the risk of breaking something, distorting the material. Even with a half etch indent you're still pushing the tool to my mind

    The first few lines of the instructions say it all, like the County, an aid to scratch building, as such I'm not even going to attempt to scratch build these parts designed by pipe smoking men in stove pipe hats, certainly not above the frames.

    I'll use them as a template and cut my own in much thinner gauge, I did consider working up some etches, but with a current turn around time of six weeks, plus the one or two to draw I've decided to roll my own, break out the hand tools, shun technology and frankly, probably make a right balls of it all :)), plus, it's only a tank engine, how hard can it be.......

    The target engine is 7219, one of the first batch and as such the cab/roof joint is different from the rest, in as much as it's a one piece upper side rolled at the cant rail into the roof, later engines have a distinct joint here, the cab side remains vertical right up to an over hanging roof panel.

    As such the kit does not facilitate that detail, so, not with standing the HMS Unsinkable (or should that be Unfloatable due to the excessively thick plate work) I'd have to make my own new sides anyway.

    Anyway, given all the above, the kit comes from a different era and design critieria, we can't justifiably criticise it for that, it will build a model and I've seen some pretty good ones after trawling the net.

    So, onward, a few hours at the bench and we have a set of frames jury rigged up, my primary concern is the frame width and 6' radius curves, it'll do it with the fine scale spacers but boy oh boy do you have some side play to control, easily +-2mm.

    IMG_9810.jpg

    The rear radial frame extension is a lap joint and thus far I can see only one row of raised rivets, rather than fight the rivet tool I just grabbed a packet of turned rivets, drilled a load of holes and soldered them in; lazy is as lazy does.

    There's a whole bunch more where the frames jog in, probably a huge stay in there which looks like it's supporting the firebox heel as well. I'll add more rivets there in due course.

    IMG_9811.jpg

    There are two critical pinch points, the rear radial truck and the leading driving axle, both require minimal side control, the other three can do as they wish, except they can't really, the issue with so much side play is the knuckles in the coupling rods, they'll be so sloppy it will probably have an affect on running.

    I still need to jog the frames between the rear and trailing intermediate axles, yes I should of done it in the flat but the kit came second hand and the instructions were missing.

    I politely asked Warren very late last night if I could get hold of a copy and by mid afternoon they were in my inbox, stellar after sales service in my books :thumbs:

    Anyway, only after virtually completing both sides did I know where, and by how much, to add the jog. Once the jog is in then I think I can probably widen the frames overall by 1 mm, easily achieved by trimming down the Scale 7 spacers.
     
    Last edited: 7 April 2021
  10. Deano747

    Deano747 Western Thunderer

    Hi Mick

    Thanks for the heads up on the GW riveter. I was wondering when I looked at the tank sides if it might be a big ask?!
    It's a long way from the workbench but food for thought.
    Coincidentally, I have the 72xx's smaller brother to build too, a David Andrews 42xx/52xx.
    Nice work, by the way.

    Regards, Rob.
     
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  11. simond

    simond Western Thunderer

    My 52 was built from Warren’s kit, using my GW rivetter. Perhaps I’m just less sensitive to the screaming metal stresses in the riveter than Mick :) .

    it seems ok, is looking forward to a 61 and a Mogul in the stash... (though the tender for the Mogul is from Javelin, because I used the WS tender for my Dukedog which will save a couple of long hours)

    given the challenges of getting the 2-8-0 version across a Peco crossover, I’m looking forward to all sorts of excitement in that department. Mine has Premier rods, and loads of side play in 2nd & 4th axles. The rods were built with a bit more play than usual, but it doesn’t seem to be an issue. I’ve probably still got the CAD I did for the sideplay if it’s of any use.

    Atb
    Simon
     
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  12. SimonT

    SimonT Western Thunderer

    These might help from my stash.
    Lap Joint. Lots of BBBs!
    Lap Joint.jpg
    Joggle frame rivets
    Frames 14a.jpg

    We build our footplates so unrealistically;)
    Simon
     
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  13. SimonT

    SimonT Western Thunderer

    PS. The second photo shows how Swindon carried the load at the back of the firebox/boiler. Sliding bearers at the top of the frames. That's what the firebox covers er, covered.
     
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  14. mickoo

    mickoo Western Thunderer

    Cheers sweetie :thumbs:

    The real frames are taller than the model which stop short at the footplate, so those sliding brackets wont be fitted. Interesting way of supporting the fire box and it looks like the rear one is welded so limits expansion/contraction.

    That's a rather big stretcher just aft of the joggle, not yet found a decent photo of that yet, plenty from there forward to be getting on with for now :)

    Frustratingly I can now see that the lap joints are bolts and not rivets and I do have some mini bolts that I could of used, I'll ponder swapping them whilst I dill holes for all the others.
     
    Last edited: 8 April 2021
  15. mickoo

    mickoo Western Thunderer

    Hmm interesting, I tried a test shot on the carrier etch and it barely dented it :))

    Side play is going to be critical on this thing, we'll see how it goes later today :thumbs:
     
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  16. SimonT

    SimonT Western Thunderer

    The back end of a GW boiler expanded backwards so there is no welded joint.
    As for the frame stay, here you go Sweetie, all the photos from those nice people restoring 4253, used for illustration and education.
    Frames 3.jpg
    2013-09-08-Frame-floor-sections-1024x768.jpg Injector 1.jpg

    There are no changes to the 72s in front of the lap joint until the tank balance pipe changes and the new cylinders which don't affect you with 7219.
    Simon
     
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  17. simond

    simond Western Thunderer

    I don't think it would, I think it would probably deform the frames or the boiler.

    If it's gonna expand, it's gonna go somewhere...

    I see Simon has confirmed that it isn't blocked.

    cheers
    Simon
     
  18. mickoo

    mickoo Western Thunderer

    Simon..T

    Much obliged, just found the top one, it's on the 7200 facebook restoration page.....very useful page picture wise ;)....they have that shot down as 7200 during it's Swindon works visit, I think for frame alignment and cylinder alignment/boring.

    I'm rapidly running out of rivets, more ordered :p

    Re firebox, okay, I can see the frame extensions that hold the firebox sides in place, but surely they must be a base pedestal somewhere to take the weight and allow it to expand rearward.

    Finally, just a correction, I got the engine number wrong, it should be 7217, not that it makes much difference mechanically.
     
    Last edited: 8 April 2021
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  19. michl080

    michl080 Western Thunderer

    Interesting! Let me add a meaningless detail how German locos had their boiler fixed on the frame:

    The boiler was fixed at the smokebox saddle to make sure that the steam tubes between boiler and cylinders were not bent. To compensate expansion of the hot boiler, so called "Schlingerstücke" were used to limit the movement of the expanding boiler. See the link for details. Typically they were located at the back end of the firebox.

    Schlingerstück

    Locos with a narrow firebox like the example in #1232 had a different concept that can be seen here:

    Stehkesselträger

    Quite comparable to the example above.

    Michael
     
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  20. Dog Star

    Dog Star Western Thunderer

    GW boilers (generally) slide on the top edge of the frame plates... for this to happen there are "L" shaped plates bolted to the sides of the outer firebox wrapper with the horizontal section of the "L" of sufficient width to rest on the frame. It is the L-plates attached to the firebox which allow the expansion of the boiler to be made at the rear of the loco - those plates can be seen above the reach rod in Simon's photos in this post. The plates are held to the firebox shell by way of nuts/ washers on steam tight studs

    As well as the L-plates allowing the boiler to slide... there are a second set of "¬" plates and those plates are bolted to the outside of the frame plates (or, in the case of 4200 and 7200 classes, frame plate extensions). The horizontal part of these additional plates is above and covers the lower angle of the plates which are attached to the firebox. Simon's photo above shows frame plate extensions and boiler hold-down plates below the reach rod. To make sense of that last sentence, find yourself a 4200 engine undergoing restoration or look for s suitable photo, we are lucky in that Simon has provided such a photo here. The photo of 4253 shows the frame plate extensions which are rivetted to the outside and on top of the frame plates, also visible in the photo are the two rows of threaded holes by which a hold-down plate is affixed to a frame plate (extension).


    Why is a second set of plates required, you may well ask, given that gravity keeps the boiler in contact with the frame. I have not seen any documentation as to why there is a second set of plates... my supposition is that the "extra" plates prevent separation of the boiler from the frame in the case of an accident and thereby avoiding imposing stresses on the bolting flange of the cylinder block.

    regards, Graham
     
    Last edited: 8 April 2021
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