7mm On Heather's Workbench - a baby Small Prairie

Discussion in 'WR Action' started by Heather Kay, 2 August 2017.

  1. Peter Cross

    Peter Cross Western Thunderer

    Looks good heather. Would the sand box lids in the cab doorway, not be recessed. The pictures I've looked at I can see no sign of them. And I know that on paniers with cab fills they were.
  2. Heather Kay

    Heather Kay Western Thunderer

    Possibly, but again it’s something I can’t see clearly in photos. I can modify the plates, though. I may revisit.
    Peter Cross likes this.
  3. Heather Kay

    Heather Kay Western Thunderer


    Righty-ho. I extricated the plates and cut holes in them. I also managed to shave some of the cast lids away so they’re a bit better recessed in the holes. It’s better than it was, anyway.

  4. Peter Cross

    Peter Cross Western Thunderer

    That looks good. Better than tripping head long out the door over them.
    Heather Kay and Rob Pulham like this.
  5. Heather Kay

    Heather Kay Western Thunderer

    With the crew Health & Safety dealt with, time for those tank tops.


    Forgive my hieroglyphics. That was when I was trying to identify which of the umpteen holes etched in the kit parts were actually needed. I’m pretty sure there are other things on the tops of the tanks aside from the filler and a vent each side. I haven’t managed to identify anything conclusive from images or drawings, not even a filler lid bumper. For the time being, therefore, I shall fit only the items positively identified.

    I have a set of Laurie Griffin low oval fillers, which look lovely. I need to get some shorter mushroom vents, which I’m hoping LG will have with him at the Reading show in a few days. If Masterpiece Models are there, I might sneak a peek at their small prairie to see what might be lurking on the tank tops that their researches revealed.

    Why make new tank tops? I didn’t fancy trying to fill holes without leaving marks. If I’d realised the issue when the parts were still in the flat, I could have dealt with it then. Hindsight, and all that. The holes are also accompanied by slots along the outer edges, where the sub-frame was folded down earlier in the construction. Better to make a filler plate to cover everything. Anyway, time for some CAD…


    Cardboard Aided Design. I began with some masking tape, applied carefully to the tops and pushed into the edges. I ran a felt pen marker round the edges, followed by carefully peeling the tape back off and resticking it down to some printer paper.


    After carefully cutting the resulting shape out, I tested it and made adjustments as necessary.


    With a good fit, I made a replica template for the other side of the engine.


    Due to the vagaries of my construction, I couldn’t simply flip the first template over. I tried, but found it was ever so slightly different. A new template was made the same way as the first.


    So far, so good. I measured and marked centres for the filler and vent locations.


    A sheet of thin brass sheet was attacked with the blunt end of my marker pen, and the templates were carefully scribed round. The sheet was thin enough to be cut using a scalpel and straight edge. This, at least, alleviated the curling problem that can be encountered using snips or scissors.


    Finally, a pair of new tank tops. Now all I have to do is work out the best way to fix them onto the old top surfaces.
  6. P A D

    P A D Western Thunderer

    Nicely out of jail Heather.

    I would be inclined to solder it around the edges while keeping it flat with a length of Mr. Costa's best stirring stick. It would be easy enough to clean up and if you can get the iron in underneath, you could run some solder through the surplus holes.

    Heather Kay likes this.
  7. simond

    simond Western Thunderer

    Heather, I hesitate to offer suggestions, as I haven’t the photo evidence to back it up, but I would expect to see a pair of fillers, and their associated bumpers, a pair of mushroom vents, and a pair of pipes through which the water fill pipes to the top feeds are passed.

    I’d also be pretty confident of a pair lifting rings on each tank, front & rear.

    Can’t think of any other excrescences but I’m sure someone will offer food for thought.

  8. Heather Kay

    Heather Kay Western Thunderer

    No top feeds on the early ones. The clacks will be on the back head. I would expect a filler top bumper, but I really can’t find evidence of any. I’ve seen two distant and blurry images with any view of the top of the tanks, neither exhibit anything further than fillers and vents that I can see.

    Bearing in mind Mr Churchward was stilling finding his feet with these new types of engines, it seems the Victorian habit of clean and tidy was still much in evidence. The flush rivets on the front of the engine running plate, for example, and the smooth cladding on the boiler and smokebox for another. Lifting rings, tool posts, smokebox stays, top feeds, fat bunkers, and all manner of other clutter were added to these little engines as time progressed, but as originally built they seem very neat and tidy.

    If evidence turns up, I shall amend and add. For now, fillers and vents is all I can guarantee fitted at the time. ;)
  9. Heather Kay

    Heather Kay Western Thunderer


    Another one of those days where a couple of steps back occurred before proper progress could be made.

    The front part of the boiler is now fitted properly. This was achieved by cutting a small slot in the base of the smokebox, which allowed me to blob some solder into it to hold it down to the saddle. The first time, it was slightly misaligned, and removing it caused the boiler to unravel a bit.

    Deep breath, followed by some careful reconstruction, and then a more thoughtful approach to fitting it worked. Unfortunately, a slight mismatch in the diameter of the coned section and the newer straight section of the boiler meant a rather obvious step. With only very slight boiler bands evident on the real thing, which meant the bands wouldn’t mask the join, this needed resolving. In the end, with some care, I pushed up the front of the coned section sufficiently to make the join smoother. Inevitably, this means some filling will be required along tank tops. I think Milliput might be the solution here, but I’ll leave that until most of the hot soldering work is finished in the area.

    For the photo I’ve plonked the filler lids and safety valve bonnet on to see how things are loooking. It’s not perfect, but it’s about the best I’m going to manage today. I’ll clean things up a bit more, then give the body a dunking to clean it up and remove flux residues.

    I was going to fit washout plugs. There are two in front of the firebox, and two behind the smokebox. Careful examination of period piccies seems to show the tidy-minded designer had small circular covers fitted over the plugs. Later on, as these were obviously prone to damage and loss, they were dispensed with. The upshot is I’m not going to hack huge holes to accommodate washout plug castings. I will, however, need to create circles of suitable size. My current thinking is something like Bare Metal Foil, punched to the right diameter and stuck to the metalwork before painting begins. The same material might make excellent boiler bands, too.

    The next stage should be fitting the tank top details, and smokebox handrail knobs. There are some running plate detail castings to fit, and then I can start to look at the backhead again. I’ll need to sort out the brake hangers, too, but I think things are coming along fairly quickly now, happily.
  10. Heather Kay

    Heather Kay Western Thunderer


    Most of the detail castings are now fitted. I’ve since installed handrail knobs. I’m definitely going to raid Laurie G's emporium at Reading - gawd! I hope he's there now! - as I’m pretty sure he does the correct pattern tool brackets for the bunker as well as the other bits I’m after.

    I guess it’s time to chase up brake gear. ;)
  11. SimonT

    SimonT Western Thunderer

    I think that you will need to get screw handle fillers. From the early photos I think that you are correct about how few fittings were on the tank tops as built.
  12. Heather Kay

    Heather Kay Western Thunderer

    I have the screw handles. I’m leaving them off until later as they’re sure to be bent and broken before I’m done. :oops:
    Rob Pulham and simond like this.
  13. Heather Kay

    Heather Kay Western Thunderer


    It was pointed out to me, off-forum, that I appeared to have been wearing my specs back to front yesterday. Even allowing for the particularly GWR arrangement of front deck lamp brackets, I did indeed fit them bass ackwards. Further peeking and poking also involved a lightbulb moment as I realised I had also fitted them too far back - a consequence of remaking the front deck using the later stayed deck as a template. The brackets shuffled about over time, of course. Why wouldn’t they?

    Anyway, off they came, it was all tidied up, and they’ve been refitted. It seems there may have a been a joker in the Wolverhamption workshops, because out of two clear images of early locos, the centre bracket is mounted in the opposite way on each. I’ve, finally, erred on the apparently final arrangement side of things, that which was adopted for the bulk of locos from this period on.

    Now, I’m considering options regarding the valve bracketry under the smokebox.
  14. Heather Kay

    Heather Kay Western Thunderer

    Back on the last page of this thread, where I was contemplating the valve operating trunnion gubbins, I ended up using the kit castings. They aren’t correct for the period, but I really felt I wasn’t able to do the mods to the castings to make them better.

    My problem is I don’t feel comfortable that I can use machine tools without breaking something. It’s usually something to do with holding the piece firmly at the right angles.

    Today, I overcame my fear.


    I pinged the bits off the frames. I picked my best Proxxon mini machine vice and spent a few minutes clamping one part as square as I could make it. I measured, measured again and followed up with another measure for good, um, measure, and centre popped. A 1.5mm bit went into the Proxxon drill press, and with fingers crossed I carefully drilled right through the casting.

    The first one went ever-so-slightly off course, but not enough to bother me. I repeated the process with casting number two, which went straighter. Buoyed by my success, I decided the holes needed to be larger - I had always intended the 1.5mm to be a pilot, but had guesstimated the final size should be 2mm. So, I redrilled with the larger diameter, but only about halfway down. The important point was I could see daylight through the castings.

    Some careful filing to straighten up the angled cover plate, and a quick zap with the RSU, and I think I’m happy with the results. Now it looks right.

    What’s next? I think I’ll consider firebox washout plug covers.
  15. Heather Kay

    Heather Kay Western Thunderer


    I thought it might be fun to start sorting out the backhead and cab detailing. Once I’d winnowed the bag of components down to this lot I kind of lost the will to live.

    Perhaps some kind GWR soul might be able to advise me on the best combination of steam/vac brake for the period. I appear to have both kinds, but I’m not clear about which might be most appropriate for the early 44s.
  16. Heather Kay

    Heather Kay Western Thunderer


    For the time being I’ve parked the boiler front/backhead works. On my past record it would take me about a day to assemble, though now I know what the various bits are it shouldn’t take that long in reality.

    Yesterday, I spent a bit of time reassembling 3107. It’s the first time she's been all in one piece for a while, and it was a good test of my abilities at making up sub-assemblies. The hope was to make her run under power for Reading, but there’s a bit of fettling needed on the fireman's side connecting rod that needs a sight more patience than I can muster at present (not helped by having a boiler repair man and mate fixing our hot water system). I’ve decided to leave the gearbox disengaged for now, the loco can be pushed around to make the wiggly bits work. The bonnet and chimney have been temporarily glued on, and the tape is holding the smokebox door while the temporary glue sets.

    I think, despite the various idiosyncrasies in the kit, she's looking very much like a small prairie now.
  17. GrahameH

    GrahameH Western Thunderer

    Good morning Heather,

    As a relatively newcomer here I have been following your build with great interest as it is a favourite locomotive of mine in this era.

    With all your trials and tribulations to get to this stage of the build does show what a lovely little locomotive she is and your determination has certainly captured the look and feel of her.

    Very much looking forward to the next stages.


    p.s. When the photograph first loaded I had to have a chuckle to myself, I've never seen a GW locomotive being held hostage before ( the masking tape blindfold ! )
  18. Heather Kay

    Heather Kay Western Thunderer

    We’ve more or less recovered from Reading. It was a splendid day, and as ever we spent way too much time chatting and discussing things than seeing what was on offer from the traders. Happily I bought most of my shopping list, which prevented the usual "d'oh" halfway back home again.


    One of the shopping list items was this beauty. There’s a casting feed I need to clean off, but it’s a brake weighshaft from Warren Shephard. It’s meant to save me a lot of bother and scratchbuilding…


    You can see how the thing is supposed to fit. The handbrake operates the big lever, which is outside the frames. Now, this is where the kit compromises come back to bite me in the backside.


    I’ve marked in pencil where the handbrake column lives, and marked a line on the frames. You can already see the recess meant for the weighshaft brackets is further back than it should be. This is, I believe, a compromise to let the frames work for the 4ft 1in and 4ft 7in versions of the "small" prairie, plus the shortened pony truck arrangement for those pesky motors and gearboxes we modellers insist on.


    With the aid of some blue tack, here’s where the weighshaft needs to fit. It interferes with a spacer, which is where the trailing truck pivot lives. The recess will need to be filled up. This is looking a bit awkward. And, yes, I know that big hole is also in the wrong place. There’s nothing I can sensibly do about that, and I knew about it from the start.


    From underneath, more potential for problems. The long lever is for the steam cylinder. With the "adjusted" pivot point - remember, on the real thing the pivot lives just between the rear springs - it’s going to make it hard to get a nut on to hold it all in. I may invert the bolt, so it screws into a captive nut, which might help. In any case, there’s all kinds of potential clashes with the steam cylinder and pony truck frame.

    As Mr Holmes might put it, this is a three pipe problem. So, while it wanders round my noggin looking for an answer, I shall get on with some other detailing tasks topside.
  19. Ian G

    Ian G Western Thunderer

    Heather would it be worth drilling a hole through the bolt and using a spring washer/split pin to secure the trailing bogie?

    Ian G
  20. simond

    simond Western Thunderer

    or an "R" clip...