7mm Mickoo's Workbench - Martin Finney 47xx - MoK Ivatt 4MT

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

  1. 7mmMick

    7mmMick Western Thunderer

    When the coal space is fitted tabs sit proud of the top plate. Don’t file flush with the top as you need them later to fit with the top overlay. If you file flush you end up with gap to fill under the tool box. Looking spot on BTW :thumbs:
     
  2. mickoo

    mickoo Western Thunderer

    Simon, simply Clostermann etch black primer, it's mainly a rust blocker.

    They look okay as is, but if the painter wants to he can simply drop the chassis in thinners to get back to the original metal wheels; I suspect he'll just blow over the whole lot with his own etch primer.
     
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  3. mickoo

    mickoo Western Thunderer

    Fore warned is fore armed ;)
     
  4. David Boorman

    David Boorman Member

    Mick, looking at the A2 photos on page 34 what jumped out at me was the appearance of the surrounds for the sandbox fillers - forgive me for ignoring all the wonderful work! - to me the surrounds look significantly overscale - or is it my judgement that is off?!
    Cheers, David
     
  5. mickoo

    mickoo Western Thunderer

    The sand box surrounds are castings so are a touch thick which may make them appear over scale.

    The remit was build out of the box and this was complied with for the majority of the build, the firebox issues were so bad they had to be reworked, after consultation with the client, the same applied to the tender coal space. Any reworks come at a cost, my time, their pocket so you have to respect their view and proceed as directed.

    The alternatives were new hand built ones or new etched ones (preferred), etched is faster to draw up and assemble but the number required falls well below the etchers minimum sheet size, you'd get at least 20 engines worth of sand filler plates.

    Thus they'd have to piggy back on another etch somewhere, at the moment I have nothing going off with a material size that would suit, so you're looking at two maybe three months before a suitable sheet arrives, in my mind that's not an acceptable delay.

    In all fairness the sand box filler plates are the very least of the kits problems and I suspect once it's all painted they will not stand out as much.
     
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  6. David Boorman

    David Boorman Member

    Such a difficult balance - 'out of the box' v. fix the obvious. I can understand why you let this detail remain.

    I really enjoy reading and observing(illustrating photos) your analysis of the kits you build - I always feel grateful that you have spent the time to record what you have found and how you have addressed issues. The effect you have had on me is to enable me to relax when I encounter problems or obvious design shortcomings in kits - I used to always default to blame myself for doing something wrong and spend ages uselessly trying to understand what I had done wrong. Your observations have taught me to be much more objective about problems encountered, plus some neat techniques for fixes!

    My learning is perhaps a little late for me as I fall into the age category that Boris Johnson suggests could result in early termination in the near future!

    Cheers and thanks, David
     
  7. mickoo

    mickoo Western Thunderer

    David, not a difficult balance at all :), the customer lays the ground rules out and that's what you stick to.

    I post copious images as the build goes along, here and Facebook, therefore there are no hidden surprises once the box is opened at the end of the build.

    The most important part of any build is harmony, there is no point adding uber perfect sand filler backing plates if the deflector has square etched on beading (that detail really pi55es me off for the record), the cab is the incorrect profile and width. In the end you virtually rebuild the majority of the kit, aka the Warren Shepard County.

    We also have to remember that some models are going to be working models, their view distance could be 6 to 10 feet away or even in the garden, sand filler backing plates that are 0.75 mm over size really isn't an issue :cool:

    If, at the end of the day, the client really decides that the backing plates are too hideous, then it'll come back here, they'll be removed, new ones fitted and the paint repaired, not at their cost either.

    However the problem will go much deeper, smaller backing plates will have to be moved back to make sure they just clear the boiler cladding, this will then reveal the great big ugly half etch trenches in the footplate used to align the cast ones.

    You now have two choices, fill those ugly slots and try to blend them flush in among all that raised rivet detail, or make a new footplate with etched slots to take etched tabs on your new backing plates.

    So you see, changing just one small part often has larger implications that go much deeper.

    Regarding kits, never sell yourself short, some of these kits are getting long in the tooth, the A2 is 15 years old now, what was acceptable back then, not only in quality, but also in fit is often not acceptable these days.

    I'm glad my dabblings are helpful, that's part of the giving that a great many others do here as well, I had to learn at one point, still am, so it's only fair to pass that along. Besides if I can forewarn others of little issues and save them time, then all good and well, quite happy to fill my swear box up if others remain empty :p
     
  8. mickoo

    mickoo Western Thunderer

    End of the week update, the Finney 47xx tender is complete.

    Nothing much to say other than, I do like the tightly wound spring that comes in the box for the hoses.

    The train buffer heads are just fitted for visuals.

    IMG_8630.jpg

    IMG_8639.jpg

    IMG_8640.jpg

    There's a couple of bits that need some Milliput to blend in and gap fill, but I'll do that all in one hit once the engine is finished.
     
    JimG, chrisb, john lewsey and 19 others like this.
  9. Scale7JB

    Scale7JB Western Thunderer

    Love that, very handsome tender.

    JB.
     
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  10. mickoo

    mickoo Western Thunderer

    Small update on the 47xx, lost most of last week to an ailment and a bit under the weather, so decided to do non commercial work, hence the GEVO updates.

    Time to play catch up now and crack on, completed the rolling chassis this evening.

    IMG_8672.jpg

    IMG_8674.jpg

    At some point I'll have to cut some slivers off the compensation beam rod and plug those holes in the frames, they're not required due to fully sprung horn guides being used.

    The last lot of LNER etched horn guides used on the A2 were perfect, clean fold, solder, drop in bearing, perfect fit, these on the other hand where the work of the devil. They'd been over cooked in the etch tank so the fold lines were too wide, resulting in a range of widths after folding the inverted U shaped guide, none of which fitted the brass bearings which all seem to have been machined from different stock. Widths varied from 7.95 to 8.08, not much to fuss over but often resulted in a jammed axle box.

    By going through them all one by one, most were eventually found a reasonable home in the variable guides and then trimmed to fit smoothly.

    Despite all that, once the wheels were in, the coupling rods only need a tweak here and there to complete a nice smooth rolling chassis.
     
    Last edited: 26 March 2020 at 12:51
  11. LarryG

    LarryG Western Thunderer

    This and other threads show there is more to being a model loco builder than just soldering the bit in the kits together. The chassis is looking good and those driving wheels look dead tidy.
     
  12. Scale7JB

    Scale7JB Western Thunderer

    Yes, those wheels are magic!

    JB.
     
  13. mickoo

    mickoo Western Thunderer

    The driving wheels are Harris and they do roll nicely and bizarrely when its rolled along it always stops with the cranks at the bottom.

    Well one slightly forward of BDC and one slightly aft of BDC.

    I thought is was a tight spot at first, but it seems there's enough mass in the metal bosses to naturally stop at the low point.

    I will be drawing up some 3D printed weights that fit around the spokes as discussed on 7mm Micks hall thread.....at some point.
     
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  14. Mudhen

    Mudhen Western Thunderer


    Mick,

    Are the wheels insulated on one side only? If so are you comfortable with the frames being live, its not something I'm fond of due to it leading to short circuits?

    Tim
     
  15. mickoo

    mickoo Western Thunderer

    Tim, looks like it from the photos doesn't it, I'll check when I get home.

    I've no feelings either way, the wheels came in the kit from the client so I'll presume he's happy with that.

    I will now have to double check the tender though and make sure there all the same way around with respect to each other.

    Then, either make sure they match the engine or (preffered for pick up simplicity) opposed and then fit an isolated drawer.
     
  16. richard carr

    richard carr Western Thunderer

    Mick

    Those wheels are only insulated on one side, that was normal practice for Alan Harris, it was extra if you wanted it on both sides, as it is a lot of extra work to do it. The crank pins should insulated too but you can't see that in the photos.


    Richard
     
  17. mickoo

    mickoo Western Thunderer

    Richard, I suspect you're absolutely correct and yes I have already checked the crank pins and they are all insulated, never though to check the wheels though.

    One thing that becomes apparent and important in commercial work, the client is always right, it's not my place to reason or have views or opinions on what they request......unless its unworkable or impractical.......where upon possible solutions will be discussed and decided.

    Personally I'd be more than happy with the US style of chassis pick up given the quality of the wheels over say Slaters. There shouldn't be any more risk of the rims on the insulated side shorting than with any other wheels, unless I missed something.

    The only problem could be buffers shorting and that's limited. It'll almost certainly be stock and unless they're coaches with lighting pick up, should present virtually no risk of conductivity.

    The only other vehicle that can produce a buffer short is another engine built to the US style pick up. Let's be honest, unless you're modelling Dainton bank there's very little chance a 47xx would ever double up :cool:

    Worst comes to worse you can coat the buffer heads, there are some clear epoxy resins out there that harden really well. I recall reading somewhere that Devcon, if heated to 100C whilst setting will harden like glass. I've not tried it though, or remembered exactly which version of Devcon adhesive it was.
     
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  18. richard carr

    richard carr Western Thunderer

    Mick

    I have quite a few locos with Harris wheels all of which are only insulated on one side, all of them are fine, except for the 9f and I still can't find the short. That doesn't matter now as it's battery powered and runs on dead track.

    Richard
     
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  19. eastsidepilot

    eastsidepilot Western Thunderer

    Couplings ?.....only I suppose if your double heading
     
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  20. mickoo

    mickoo Western Thunderer

    Yeah forgot about them, living proof that my railway interest declines exponentially past the buffer faces :p
     
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