Stanier 8F in S7

Discussion in 'S7 Group' started by DavidinAus, 8 February 2014.

  1. Ian_C

    Ian_C Western Thunderer

    Congratulations - looking good. I really ought to get started on mine. Just gotta save more money for wheels, motor.

    Question - I'm thinking (thinking's the easy bit!) of installing CSB suspension. What does your engine and tender weigh now it's complete?
     
  2. adrian

    adrian Flying Squad

    I'd be very interested in that as I was planning a similar route.
     
  3. DavidinAus

    DavidinAus Western Thunderer

    OK, I have just weighed them:
    The locomotive is 1065 grams, the tender is 500g.
    If I might offer some gratuitous advice , I wouldn't alter the compensation mechanism on the locomotive. I haven't had any trouble with it, and it seems to work well. The tender is another matter, and if I were to build another MOK 8F, or any other tender for Scale Seven, I certainly wouldn't go for the compensation by the method MOK uses, and I would probably go for individual wheel sprung suspension.

    I'm sure you will have seen the discussion further up this thread, and clearly I have spent a lot of time thinking about this. If you think about the geometry of just the rear four wheels of the tender, then the mechanism used by MOK means that there is a pair of points perpendicular to the rails vertically beneath the compensation beam about which the four wheels move up and down in balanced pairs. In itself this is good, but it means that with the fixed front axle, you end up with four fixed points with reference to track level. This means that the mechanism reduces a six-wheel vehicle without any compensation/suspension to an effective four-wheel vehicle without any compensation. This clearly works well enough in Finescale, but it (perhaps) explains why I have had so much trouble in Scale Seven. I cannot face doing it now, but with the construction involving inner and outer chassis/frames, it would be relatively easy to install individual springing in the model when starting from scratch, and that is what I would recommend.

    I don't know what CSB suspension is, but looking at Mickoo's posts earlier in this thread I think that means wire on top of the horn blocks. If that is the case I don't believe that it will offer enough advantage over the MOK compensation mechanism (if any) compared to the amount of work that it will involve. This is particularly going to be the case if electrical pickup is going to be used from the loco. itself. I have pickup from the tender only.

    This is the section I have inserted in my rewritten instructions about how I adopted Steph's split axle advice [< Split axle pick-up in 0-gauge, Page 3 > and < Split axle pick-up in 0-gauge, Page 2 >] in my tender:
    ******
    In Scaleseven models there is sufficient clearance between the back-to-back wheel dimensions to allow split axle pickup arrangements to be made. To do this, first obtain single-sided printed circuit board, approximately 1mm thick, and cut into small squares corresponding to the dimensions of the loose links. Carefully drill a hole the same size as the outside diameter of the smaller part of the brass bush in the centre of these squares of PCB, then use epoxy or cynaoacrylate glue to fix PCB squares onto the outside of the loose links, using the brass bushes to ensure they are central (don’t allow the bushes to be fixed in place). Remove the brass bushes and from the inside, use a countersink tool or equivalent to open out the inside of the loose link, thus insulating the loose link from the brass bushes when they are reinserted. Pickup wires can be soldered to the bushes themselves or to the copper surface of the PCB, which is in contact (soldered to?) with the brass bushes. Split axles connected to the wheel rims allow electrical pickup this way. The same process can be used for the fixed axle of the tender, allowing for pickup through all six wheels.
    ******
    (complete modified instructions available by Dave Sharps permission from reversed <moc.liamg@dehsluocdivad>)

    It would be much easier with Slaters individual sprung units and insulated horn blocks.

    David
     
    Last edited: 6 January 2017
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  4. Steph Dale

    Steph Dale Western Thunderer

    David,
    I agree with your last paragraph, my MOK Q1 has the tender chassis in that form and it works very well.

    Steph
     
  5. Lancastrian

    Lancastrian Western Thunderer

    Adrian,

    That particular example would be form the Horwich built batch, so would not have the vertical rows of rivets up the centre of the cab sheets. Fixed front windows on the cab sides. The exhaust steam injector would be a Davis & Metcalfe Type J, rather than that provided in the kit. Water spray pipes in the tender coal space. The rear cab floor support should have 5 lightening holes. Two piece fall plate. Also, the tender axlebox spring hangers are the "knock-back" type as found on the Ivatt tenders. A lot depends on how much additional detail you wish to add, especially between the locomotive and tender.

    Ian
     
    Last edited: 18 January 2017
    adrian likes this.
  6. Lancastrian

    Lancastrian Western Thunderer

  7. DavidinAus

    DavidinAus Western Thunderer

    Small Black with numbers 1.JPG
    Even at this stage there are mistakes to be made, and lessons for others to learn from, perhaps.

    Small Black with numbers 2.JPG
    For those who see these things there are several problems with the above locomotive.
    Most obvious is the water-based varnish covering the letters and numbers.
    Perhaps less obvious is the lack of window-glass.
    Least obvious (perhaps) is the fact that the central two pairs of driving wheels in the second picture are not exactly on the rails ....

    In order.
    I have had trouble with solvent-based varnish destroying transfers in the past, so once my "Fox" transfers were in place I fixed them with RailMatch water-based matt varnish, with the results shown in the pictures. This in itself I did not see as too much of a problem, because I thought that once an airbrush-applied coat was put on, the streaking would vanish.
    My mistake, though, was to use a short-cut and (thinking that the varnish already there would protect the transfers) I used a "Testors" aerosol "dullcote" varnish on the tender sides. Do not try this.
    Whilst the transfers survived, it produced bubbles and wrinkles in some of the plain paintwork!

    Incidentally, I don't yet know what varnish I should use. Perhaps dilute the RailMatch water-based varnish?

    Disaster. They were large enough patches that, even allowing for my intention to produce a weathered appearance, I could not leave them as they were. I didn't want to have to do the whole sides all over again, so rubbed off the sections of affected paintwork with a glass fibre brush, back to n/s metal, then resprayed with primer, masking the letterwork.

    Small Late corrections 02.jpg

    Then I resprayed with matt black.

    Small Late corrections 04.jpg

    It isn't perfect by any means, but after weathering I don't think the differences will be visible.

    Next the windows.
    Initially I wanted to use microscope coverslips to make real glass windows, and even bought a tungsten scriber to cut the glass. however I soon realised that the coverslips were incredibly fragile, and I thought that in my hands would soon be broken in place on the loco., when replacement would be very difficult. Also I realised that there was no way to produce the front-facing windows on the cab from glass, anyway. Whatever method I used, I realised that the front windows were going to be impossible to position without taking the cab roof off. So rip it off I had to do (well, carefully unsolder and lift it off ....).
    Using plastic "glass" was OK until I was unwise/uneducated enough to use cyanoacrylate to glue the side window frames in place. Araldite had been fine to secure the plastic sheet to the frames, but cyanoacrylate has made some of the glass go "misty". Well, I suppose there may have been quite a bit of steam in the cab at times ....
    So, don't use cyanoacrylate near clear plastic, or it soon will not be clear.

    Finally the problem with the wheels.
    Once again, this is probably something a more experience model-builder would have avoided, but bear in mind that this is the first tender engine kit that I have ever made - three tank engines and a Garratt before this.
    This illustrates the problem, and my solution (so far - I haven't fully tested it yet!

    Small Late corrections 03.jpg

    The MOK kit comes with a drawbar which has a disc at one end and an elongated disc at the other (running-track shaped). Naively, I went for the close-coupled length.
    It looks good, and would work well on straight track, but on curves the tender will not articulate enough with the locomotive, and one or other comes off the track. The problem was that I had cut off the extra length of the elongated end of the drawbar. So I have had to reconstruct it from flat brass strip and solder it onto the drawbar, as shown. With a slot at the tender end, I'm hoping that the tender can look realistically close to the engine itself when pushed together, but will move apart enough to go around 2m radius curves when in forward motion. We will see eventually if this works!
    So, when choosing a drawbar length for a tender engine, bear in mind the radius of the curves it will need to traverse. Don't "burn your bridges" until you've tried it on the track.

    Incidentally, those who have followed this thread may notice something has changed in the pictures. My sons were worried that me using their pool table for pictures might end up in disaster to the green baize, and so we have now constructed a wooden top for the table! Time made by our recent weather - Australia really is a different world of weather. It is still warm, but we've had over 150mm of rain in the 5 days, and so plenty of time for making things like table-covers - and model locomotives, of course!

    David
     

    Attached Files:

  8. simond

    simond Western Thunderer

    David,

    You might try springing the drawbar for your tender. If there is space, a spring, arranged so that it pushes the tender towards the loco, but allows it to move back a bit to accommodate curves, might be a solution.

    Best
    Simon
     
  9. Yorkshire Dave

    Yorkshire Dave Western Thunderer

    I use Vallejo or Alclad now. I have used Testors Dullcote but it's becoming expensive.

    Vallejo is acrylic based and they also have their own thinners. Alclad varnishes are solvent based and do not require thinning. I generally use Alclad matt as the final coat.

    I have recently used Railmatch acrylic BR blue and thinned this with Tamiya thinners.

    I've had Testors Dullcote and Microsol destroy Fox decals in the past. When applying decals I always paint the area to receive the decals with gloss varnish. In the case of this SSW boxcar here in post 60 the entire vehicle was sprayed with Vallejo gloss varnish, decals applied. Once dry I then applied Alclad matt varnish followed by weathering.
     

    Attached Files:

  10. DavidinAus

    DavidinAus Western Thunderer

    Addendum to the above:
    With judicial use of a number 11 blade, the two window frames have been removed.
    So I am going to use microscope coverslip glass after all.
    I've cut it to size with the scriber, and will glue it using Araldite. It looks good, of course. I just hope it doesn't crack in use.
     
  11. BrianG

    BrianG Member

    Sorry to see the results of using acrylic varnish, and other products, to cover your Fox transfers. I have had no problems at all using Phoenix Precision dull varnish (in the ready-to-spray tinlet) directly onto the transfer, despite the fact that I had applied them over dull finish paint and not gloss as Fox recommend for best adhesion.
     
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  12. Les Golledge

    Les Golledge Active Member

    I'm sure you will have seen the discussion further up this thread, and clearly I have spent a lot of time thinking about this. If you think about the geometry of just the rear four wheels of the tender, then the mechanism used by MOK means that there is a pair of points perpendicular to the rails vertically beneath the compensation beam about which the four wheels move up and down in balanced pairs. In itself this is good, but it means that with the fixed front axle, you end up with four fixed points with reference to track level. This means that the mechanism reduces a six-wheel vehicle without any compensation/suspension to an effective four-wheel vehicle without any compensation. This clearly works well enough in Finescale, but it (perhaps) explains why I have had so much trouble in Scale Seven. I cannot face doing it now, but with the construction involving inner and outer chassis/frames, it would be relatively easy to install individual springing in the model when starting from scratch, and that is what I would recommend.

    I don't know what CSB suspension is, but looking at Mickoo's posts earlier in this thread I think that means wire on top of the horn blocks. If that is the case I don't believe that it will offer enough advantage over the MOK compensation mechanism (if any) compared to the amount of work that it will involve. This is particularly going to be the case if electrical pickup is going to be used from the loco. itself. I have pickup from the tender only.
    David[/QUOTE]

    Hi David,

    Here's a couple of links to other threads that may help you with reworking the tender suspension:-
    My 7mm dabblings
    Post 584 for axle bearing Mods also the springs can be underhung as well as the usual overhung type.
    Brettell Road, 1960s black country (ish) Post 46
    this shows springy beams but in a much simpler way by ctting each beam in two and using just two spring support pivots.
    Regards,

    Les.
     
  13. Ian_C

    Ian_C Western Thunderer

    Late comment maybe, but for matt varnish try the AK Interactive range of military modelling acrylics. I get on very well with AK Ultra Matte.

    I have gearbox and wheels for my 8F now so I've no excuse for not getting started. First problem is with the Slaters wheels. None of them run true. Seems to be an inevitable consequence of how they're designed and manufactured. Any ideas how they can be improved? I'm thinking either: tweak them back by hand to where they should be, or boring the axle inserts out to 3/16" in the lathe and using telescopic axles. Anybody done that?
     
  14. Dog Star

    Dog Star Western Thunderer

    Please talk to Slaters first - David is likely to want to help sort your concerns.
     
  15. Andrew

    Andrew Active Member

    Hi Ian,

    I can offer some advice to improve the wheel runout you have reported. You are right to point to the manufacturing process, as the machining of the axles ends and the wheel centres can throw up tiny burrs and may cause the wobble problem. Firstly, gently rub the back of the wheel on a sheet of fine emery paper until the brass hub insert, spokes and tyre are completely flat. Then take a fine needle file and just wipe each of the four machined flats on the axle ends with a couple of light strokes only, which should remove the aforementioned burrs. Incidentally, I believe that this advice is now included in each pack from Slaters. Re-assemble the wheels and hopefully the problem will be eliminated. However, if the wobble is significant, then the advice given by Dog Star should be followed as you are unlikely to improve matters to your satisfaction.

    Good luck.

    Andrew
     
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  16. Ian_C

    Ian_C Western Thunderer

    Thanks for advice on this. I've done some thinking, talking and measuring and I'll start a workbench thread and post findings there. Summary here: carried out the emery exercise and checked/removed burrs. Improved somewhat. Further tweaking in a lathe got them all to around 2-3 thou TIR. that's as good as they're going to get I think. Much improved but wobble still just visible. I'll use them in that condition and see how I get on.
     
  17. DavidinAus

    DavidinAus Western Thunderer

    It has taken a long time (I started this thread in February 2014) but at last I have the locomotive running on my model colliery line. I had to relay some of the somewhat rough trackwork to allow the eight-coupled locomotive to go around the curves, and up and down the gradients I have made in the model.
    In fact at the end of the first video you can see the engine derail, and at the end of the second one you can see it grind to a halt due to poor electrical contact.






    However, for me it is a triumph to get the engine to run the whole way around. It is the first time I have been able to do so with a scale seven engine with more than four coupled wheels (my industrial Garratt is really two 0-4-0 engines coupled together from this point of view).

    There's still a good way to go, however - I want to make it more realistic with weathering (as you can see, some of my wagons are weathered but others are still pristine), and the running still needs to be made more reliable (although I really suspect that the track work is more to blame than the engine).
     
  18. Mr Grumpy

    Mr Grumpy Western Thunderer

    It's always a great sense of achievement to see your loco running on your (or any) layout :thumbs:
    She looks superb and your layout looks really interesting too. You now need one of Dave's 9f's to complement your superb 8f :). Any chance of some close ups of the colliery and your Garret?
     
  19. DavidinAus

    DavidinAus Western Thunderer

    It will be a pleasure, Mr Grumpy.
    I will put together a few pictures.
    D
     
  20. Ian_C

    Ian_C Western Thunderer

    Congratulations. Lovely to see it running. And thanks for the whole thread, I'm following in your footsteps with my own 8F.