Finney7 Princess Coronation Build

Discussion in 'Workbenches, including workshop techniques.' started by Focalplane, 14 February 2019.

  1. P A D

    P A D Western Thunderer

    This also applies to the Gladiator kit.
    Cliff Williams likes this.
  2. Focalplane

    Focalplane Western Thunderer

    If it's hopeless why is it still in the instructions? I am leaving it where it is until I know for sure.

    And I have already reduced the rubbing plate width as this was mentioned in Richard's build.

    Anything else? (Sorry to seem tetchy but it's late)

    Cheers, Paul
  3. mickoo

    mickoo Western Thunderer

    The projection on the bogie stretcher and bogie frame stretcher are part of the original design from Martin; they have been part of the core design since it was released and to be fair, there hasn't been much wailing and gnashing of teeth over the years that I'm aware of, so it must work for some.

    It's left in the instructions because it's still part of the etch work. Until a revised set of etches or another form of pivot point is developed then it really has to stay in there, otherwise builders will be left unsure of what to do.

    The front end of the Pacific Coronation is impressively tight, as are most Pacific steam engines, the W1, A4 and Bulleid light Pacific are no exceptions and indeed the King and Castle class with their inside cylinders are also very tight.

    Our problem (modellers) is that we are pushing the engines to their maximum curvature, on the real thing they will do this, but more often than not the wheels will impact the frame or specially designed expendable rubbing plates, we can't allow that as it'll generate a short.

    Therefore there will always be a compromise, where or how the individual chooses to do that is their prerogative.

    Our aim (Finney7) was always to reintroduce as much of the range as soon as was reasonably practicable. After that it would be new models and looking back at the range, with a view to tweaking them here and there using the benefit of experience and today's modern building techniques.

    In which case the Princess Coronation bogie may come under review, is the current pivot point satisfactory, can it be improved, can the improvement be implemented without recourse to a whole new front end. These questions and many more we do not have the answers to...yet.

    My advice would be to leave the pivot point and stretcher extensions in place and try them, you may find everything works fine, you may not, if so then you can begin to explore alternative arrangements.

    The front bogie is a mini kit in it's own right so is quite complex, the only other part that might come close is the backhead, have a good look at Richards as he has some nice tips on layering the approach so that you do not end up trying to pass pipes under ones already fitted. Again like the bogie and the Bulleid backhead, it is a mini kit in it's own right.

    Mick D
  4. Focalplane

    Focalplane Western Thunderer

    Thank you, Mick, for your detailed explanations, much appreciated.
  5. Focalplane

    Focalplane Western Thunderer

    Next up, the trailing pony "mini-kit". This was certainly easier than the leading bogie but still gave some problems with the spring castings whose hangers have to be cut and shortened. One side side I cut them, on the other I drilled through the spring and pushed the hangers up through. The latter was easier and more secure.

    The wheels and axle can be removed during painting.

  6. Focalplane

    Focalplane Western Thunderer

    Next page of the instructions addresses the cylinders and motion brackets. I decided to do some etch folding of the motion brackets this evening while watching TV (you can probably guess the subject!):


    These are lovely detailed etches but quite difficult to fold even with the right tools. I can't go much further until the 10BA taps arrive from the UK, though I could start on the footplate and resin castings I suppose.
  7. mickoo

    mickoo Western Thunderer

    There is a simple way around the 10BA tap issue.

    Open up the holes in the tabs on the frame sides, clearance for 10BA is about 1.8 mm, then solder 10BA nuts to the underside of the tabs.

    Be careful when you come to drill the clearance holes in the cylinder assembly, the 10BA fixing holes are listed with a 2.4 mm clearance (page 9 fig 8), don't, they're a touch too big, 1.8 - 1.9 mm is just fine.

    To be fair the cylinder is a good fit so the overly large holes make no difference to alignment, but there's little material left for the screw head to hold. On my screws with a 2.9 mm head there's only 0.15mm around the rim to hold it in place, luckily I only drilled one before the penny dropped.

    I'll make a note and adjust the instructions for future publications.


    You can see the overly large fixing screw hole at top right; the reduced clearance hole is top left.

    Hope that helps

    LarryG, Len Cattley, markjj and 4 others like this.
  8. Focalplane

    Focalplane Western Thunderer

    Thanks, Mick, good advice indeed. I am expecting delivery of the 10 BA taps today, hopefully, so I can then move ahead with the front (utility) frame extension. The 10 BA nut solution has its own problem for me, as I do not have the spare nuts! So I will try tapping the frame spacer first and see how that works out. There is another solution, though, which would be to solder a small square of nickel silver under the fixing hole and then drill it out and tap the resulting thicker substrate.
  9. mickoo

    mickoo Western Thunderer

    If you just tap the tabs 10BA you will be fine, they're 1mm thick so take a thread just fine. The nuts option was instead of a tapped hole workaround.
    Focalplane likes this.
  10. LarryG

    LarryG Western Thunderer

    That front frame extension is a lovely piece of metalwork. It brings to mind the engineering exhibits at the Manchester Corn Exchange railway exhibition, which was my main reason for visiting every Xmas (in 'owden days). :thumbs:
  11. Focalplane

    Focalplane Western Thunderer


    I had a similar experience visiting the annual Southampton Show on the Common. A marquee full of model engineering items, including large scale steam locomotives, represented the craftsmanship of Eastliegh based railway workers, many of whom I have assumed worked for LSWR/BR. That would have been in the mid 1960s when Merchant Navy class pacifics still hauled the expresses out of Waterloo toward Bournemouth. Very inspirational indeed as are so many of the threads on WT.
  12. Focalplane

    Focalplane Western Thunderer

    Well, the 10 BA taps arrived at noon, but that is roughly when the last day of 6 Nations Rugby started, so nothing has been done. It's now 9 p.m. and we have been celebrating France's narrow win over Italy, Wales' domination of the tournament and finally the incredible comeback by Scotland at Twickenham. Well done World Rugby!

    Depending on the weather I may report progress tomorrow. Today saw blue skies, very little wind and the urge to go indoors to watch TV. Such is life!

    I should explain to non-rugby fans that I was born in Warwickshire (the home of rugby) and that southern France is crazy about the game, so much so that a few years ago I had a flat tyre in Beziers the day after England beat France in Paris and the England coach was Brian Ashton (no close relation). The garage owner where I took the car asked for my name to write on the duff tyre and I spelled out A S H T O N. He smiled and shook me by the hand and exclaimed what a good match it had been.

    Well, the 6 Nations is over so hopefully you can all expect further progress on a number of projects!

    Ressaldar, adrian and daifly like this.
  13. Focalplane

    Focalplane Western Thunderer

    This morning I negotiated 10 minutes (before setting out on a windy but sunny hike) to tap the 6 holes in the utility frame extensions. All now successfully done but here is a lesson for others: It is far better to tap the holes before the half etch tabs are formed into shape! I managed to twist one off but then soldered it back on. It would have helped if I had also run a sliver of solder in the bend as a strengthener. Later on I hope to solder together the frame extension but right now, well, the sun is shining and its Sunday afternoon, time for a siesta!
  14. mickoo

    mickoo Western Thunderer

    Did you take the cusp of the inside the tapped holes first, if not you should. Leaving it on makes that part of the whole below size for tapping and being nickel silver quite a tough job for the tap to cut through.

    It always pays to open etched holes that are going to be tapped with the correct sized drill, couple of reasons, the designer may have designed them below size to be sure there is material there to be cut...nothing worse than having oversized etched holes.

    Second, if the etchers under cook the etch the hole will be slightly smaller. The inverse of this is over cooking where the hole is too big, which goes back to developers making holes smaller to cover that off.

    In short, never trust an etch hole that is going to be tapped being the exact right size out of the box.
  15. Focalplane

    Focalplane Western Thunderer


    I did open up the holes but after bending them they must have got weaker and one did fail. It was my fault. The old gung ho spirit!

    All good advice, Paul
  16. mickoo

    mickoo Western Thunderer

    No problems, I find a bead of high temp solder in the crease can help.

    To be fair the cylinders sit nicely in the frames with little movement anyway, so the four tabs are not taking much, if any load; you could easily live with three is push came to shove.
  17. Focalplane

    Focalplane Western Thunderer

    The Utility Front Frame (different from mickoo's version) started to come together this evening:



    The components are quite different and the sequence of construction also appears to be different. The brackets for the interior valves are ready as is the front buffer beam and steps but nothing has been soldered at the front. It all sits together very nicely and the main reason for not soldering anything is that it may be better to add small brass castings before doing so. I am taking my time on this as it would appear to be very easy to solder a whole lot of pieces and then find one piece that should have been added at the beginning. Dry runs are therefore a good idea!

    As we are doing different front ends, it might be worth adding my own prejudice. I like the utility frame far more than the curved frame so typical of British outline steam. Although the utility front frame was not designed to be seen under the streamlining, it is interesting that many subsequent designs from the LMS and then BR had the utility front end and this appears to have been a result of Riddles' stay in America after the start of WWII. Certainly Ivatt's designs (think the 2MT and 4MT moguls) reflect the same architecture, the 4MT being positively "American" in style. Ease of maintenance is usually the reason for the later designs but it is interesting that it came about in a locomotive design that was far from easy to service. Perhaps Sir William Stanier had decided early on to get rid of the streamlining as soon as possible?
  18. LarryG

    LarryG Western Thunderer

    I believe it was to facilitate the removal of valves without having to remove a portion of the running plate.
    simond likes this.
  19. Focalplane

    Focalplane Western Thunderer

    Slow but steady progress today on the front frame. I have added many of the brass castings and small etched pieces and everything fits, even the front frame to the main frame is a nice tight temporary fit. The frame parts have yet to be soldered in place but are rock solid.

    Some photos:



    IMG_0102.JPG IMG_0102.JPG


    There may not be much activity on this project for a few days - I am expecting delivery of a SolderPro 120 butane soldering iron before Thursday and would like to wait until I have practiced with it.

    The Birmingham Scot coaches need some attention and, well, Penmaenpool waits for some scenery. I have to say the Finney7 kit is hard to put down. Challenging but satisfying!

  20. Focalplane

    Focalplane Western Thunderer

    Well, today I received a package containing a Solderpro 120 "quality heat tool" a.k.a. butane soldering iron:


    It appears to be a well made tool. It is shipped without any butane fuel for the usual transportation reasons. But I thought I had two types of fuel in stock, so "no problemmo". Except that one container is a propane-butane mix that has the right connector to charge the Solderpro while the other is a butane only container by Camping Gaz which does not have the right connector! After an internet search I learning something not in the instructions that come with the device - do not use a propane-butane mix! And this from the maker's website.

    So I have no way of testing the tool just yet. I have waited over a week for the device, now I have to wait until I can get the right fuel container with the right fuel. But all has not been negative today - a great lunch at a favourite restaurant in Port Argeles under sunshine and blue skies.
    Rob Pulham and michl080 like this.