Nick Dunhill's Workbench - Scorpio GWR Queen Class

Nick Dunhill

Western Thunderer
Happy New Year to all. This is my first post for a month or so, I thought I'd have a break from social media over the holiday......well that and the fact that I wasn't making anything of note. I made a F7 BG Rover such a brilliant kit that there didn't seem much point in posting a build thread (I'll post some pics when I reassemble after paint,) follow the instructions and you can't go wrong. I also reassembled a couple of Peircy B1s after paint that were built by someone else.

Just before Christmas though I started my second annual Scorpio Queen build! I actually made the last one in 2020 but didn't post anything about making it, just a few pics of the finished loco.

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My last experience of the Scorpio Queen kit (and the GWR BG Armstrong Convertible I made from the same source) was very good. The instructions are good, although I had to do a lot of cross referencing, but maybe that's just the nature of the prototype. The etchings are excellent and fit together very well, and most of the castings are good too. As you can see above it made a very acceptable model.

I began with the chassis. It has rocking beam suspension which looks a bit Heath-Robinson esque but works very well. I didn't bother with the Scorpio option of a special gearbox fitted with different gear ratios on each shaft of the motor to drive the rear and centre axle. It is designed round an unobtainable Mashima motor and it also looked a bit H-R esque (perhaps I am wrong and it works well too!)

Instead I used the same system that myself and DLOS had discussed sometime ago before he sadly died. He suggested moving the pivot of the rocking beams closer to the centre (driven) wheel. In this way a lot more of the weight of the loco is transferred to the centre driven wheel, and hopefully it will pull a bigger train. I moved it 12 mm closer to the centre axle, a lot of precision drilling is required. I used the old hole for the rocking beam pivot to mount an anchor rod for the motor.

The rest of the build so far is as per instructions. I fitted the model with a Mashima 1833 style motor from Taff Vale Models mated up to a foldy-uppy gearbox from the same source. I like both the motor and gearbox from TVM, if you build the gearbox carefully and shim it out properly it runs very sweetly and quietly, it has Ultrascale gears. The motor seems nice and powerful too. Julian Wynn hasn't paid me to say this!

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Here it is having a bit of a test run, and there's a few more pics here;


 
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Nick Dunhill

Western Thunderer
In the last few days the chassis has been fitted with the mudguards and the dummy inside motion. There were a couple of inside motion parts missing from the box, and I'm sure that a call to Pat or Jeff Ennis would have resulted in a package by return of post. Luckily I had some inside motion parts left over from my GWR BG Armstrong convertible project that fitted the bill nicely.

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The mudguards are fiddly to make and attach, but again that's the nature of the prototype.

The brake hangers and brake blocks are made by zig-zag folding up of multiple layers of etches. The hangers are in two parts with the blocks sandwiched in between. These were supremely fiddly to fabricate from the etches but the end results were very good. Again I think Scorpio have tackled the structures in the best most practical way and a casting would have been too chunky.

As I said above I didn't post a blog when I made my first Scorpio Queen in 2020 and I wish I had! The brake hangers for the middle wheel are about 2.5 mm too long, or the parts are identified wrongly in the instructions. The memory of this came flooding back as I assembled them!

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Here's the remedy...

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...and the final result.

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As usual a lot of care has to be taken when assembling brake gear with pull rods round both sides of the wheel. They need not to touch! Also they need to be detachable so the wheels can be removed for paint etc.

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I have fabricated some sand pipes from brass rod and will attach them to the centre wheel brake hangers on monday morning. Then the loco bodywork begins......
 

Nick Dunhill

Western Thunderer
A fair bit of progress this week, I started with the footplate. It's in 3 main parts, you begin by forming the outer frames and then curve the footplate top to fit. Forming the outer frame structures needs some precision and care. I mocked them up with tape before soldering together, constantly checking for straightness and squareness.

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When this was done I carefully formed the curve in the footplate top and attached it to the frames. I used the slots for the fall plate as a datum point. The top was soldered to the frames and the finishing strips attached under the footplate edge. The buffer and drag beams finish the structure off.

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It is very hard to make this structure, but the etches are accurate which helps greatly.

The splashers were added next and the buffers.

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The cast buffer stocks provided were a bit badly cast. I had some spares that Pat Ennis had sent me for a previous job and these were really good so I substituted them. The castings were blind and drilling them out isn't a trivial job. I had the usual issue with holding them whilst drilling white metal, which constantly cloggs up your drill bit. In the end I sleaved them with brass tube and they now work perfectly. The coupling is from CPL.

The cab was next. Again all the etchings are spot on so it was quite an easy task.

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The tapered handrails are made by filing a length of 1 mm rod held in a mini drill. The rod is filed whilst rotating against a wooden block.

I made the backhead and detailed it up. I added a few extras, and will add more as the boiler is constructed.

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The final task this week was to form the boiler and firebox. It was pre-rolled and it was difficult to form the bottom of the firebox once it had been rolled up with the boiler. I had to spend a lot of time dressing out creases that had formed where I didn't want them. The formers fitted very well though and when offered up to the footplate and cab it fitted almost perfectly.

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More boiler action next week, and there's more pictures here;

 

Nick Dunhill

Western Thunderer
So we have chugged along for another week and I have completed the main structures of the loco and most of the detailing work. The Smokebox structure was too wide at the bottom and wouldn't fit between the frames above the footplate. Next time I make one of these locos I should narrow the front and rear formers appropriately. The instruction leaflet does fess-up to this in all fairness, it suggests a work round, but I elected to chop the smokebox wrapper to end on top of the frames.

There's a casting provided to represent the brass cover plate between the boiler front and smokebox rear. It needs a bit of straightening but fits very nicely.

I offered to boiler structure up to the footplate and cab, checking for squareness and checking again, and the assembly fitted well with only a minimum amount of adjustment required. I finally took a deep breath and soldered it all together.

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I then spent a happy day fettling and polishing boiler fittings. The SV and dome fitted well but the chimney did not. The base of the chimney has a radius much too small for the smokebox, and the chimney stack is off to one side. I will weigh it in with the rest of my brass and NS scrap in the summer and treat myself to a nice bike ride to a posh Peak District pub for a good lunch! Iain Young (Sans Pareil) sells GWR River cast copper chimneys that are the same as those fitted to Queens. Result!

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Then it was just a case of ploughing through all the body detail. Springs, lamp irons, valve cover, injector clacks, steps etc etc. This part is surprisingly time consuming. The white metal sand boxes were very poor castings, so Mick Davies 3D printed me some.

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I have to make the handrail round the boiler, add a couple of smokebox fittings and glue some lead sheets in the boiler and the loco will be finished. It's a nice kit and the etches are very accurate.

More pics here;

 

Nick Dunhill

Western Thunderer
Well here it is with all the detail added and mocked up. I just noticed I haven't fitted a vacuum pipe so will raid the bits box tomorrw (there isn't one in the kit!)

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It runs nicely on analogue and digital, and I managed to shoehorn enough lead in it to bring the weight up to about 900g.

I'll build the tender in a week or so, but first I have a Z and a Rover to reassemble post paint!
 

Scale7JB

Western Thunderer
Not the biggest BG fan here, but that is a truly handsome engine! Lovely job.

Have you tried the old ‘spit on the drill bit’ trick when drilling whitemetal?

JB.
 

Nick Dunhill

Western Thunderer
After a week or so faffing with a Z and a Rover it's back on with the Queen tender, although there'll be a bit more on the Z when the painting is done. The kit came with the wrong tender for my build, which Jeff and/or Pat Ennis swapped for the cost of the postage. The model represents a Queen towards the end of it's life, post BG, with a Dean 3000 gal tender. The tender is nearly the same length as the loco and is much bigger than the original Armstrong tender.

The chassis is cunningly designed with a rocking beam system enclosed inside the well of the water tank, as with the loco all the etches are very accurate. It is easy to build, but I swapped out the brass bearings supplied in the kit with some from my stash, as the OD of the kit bearings was smaller than the etched hole in the rocking beams.

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The water scoop components fit together nicely and mount on the bottom of the water tank. The brake hangers and blocks are fabricated fron some zig-zagging etches, which are a bit of a faff to make but probably the best solution to making this type of assembly. The brake hangers and rigging are designed to be hung from some rods attached to the rocking beams. Attaching the rigging would connect the brake hangers on opposing sides of the tender and prevent the beams from functioning unless a clever system is designed to allow the rigging to move with the suspension. I was certainly up for the challenge of this but the budget for the build was not! I made some new mounts, attached to the water well sides, and moved the brake hangers rearwards a fraction to allow vertical movement of the wheels in the rocking beams. It functions well but wasn't so much fun to build.

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The axle boxes and ouside frames were assembled next. These tenders carried a variety of types of axleboxes and all are catered for in the kit. The frame etches are designed to be modified to suit. The nett result of this though is having to assemble each axlebox/spring /hanger assembly from 4 different castings. Good job I reduced the budget above!

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The footplate is made from a clever lamination of several etches, they are very accurately produced and allign nicely. You then fold up the tender inner structure. I had an issue with the design of the half etched tabs that have to be folded through 90 deg to support the front coal space etch. I guess the time spent in the etching bath dictates where the fold of the half etches will occur, and in this case the spacings produced to mount the inner structure was too tight. I cut off the half etched tabs and replaces them with some internal runs of L-section brass. These give the same (correct) allignment of the tender tank assembly.

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Next was the dreaded GWR tender side flares and corners. The tender side is a very long etch that has to be accurately folded (using a 4 mm drill shank) to fit round the above tank assembly. First though I formed the flares at the top of the etch. This was done by taping a suitably sized rod to the top of the etch and manipulating it by hand, a section at a time. First one side, then the rear and finally the other side.

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Then the front of the tender sides have to be modified to give the correct shape. There are cutting jigs supplied in the kit to support you with this task. The etch fitted very nicely round the tank and located nicely into the half etched locating slot round the footplate top.

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The dreaded corners.....I elected to flood the fingers with solder rather than try to insert a casting. It takes lots of care to file the solder to shape. There's no secret apart from patience, and accurate alignment of the fingers before applications of solder. I was pleased with how these turned out, although they look crap in the photos.

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More next week and more photos here; nick dunhill
 

Nick Dunhill

Western Thunderer
We're on the last leg! The coal rails are a complete faff to make. They have to sit above the flare in the tender side and be straight and parallel to each other and the tender. The corners have to be the same radius as each other and the tender corners. The best place to start is to plant the mounting posts in the correct places. The kit has special posts that fit over the ends of the division plate and the front coal plates. I started with the division plate making sure that it was central, then the front coal plates and their posts. The free standing posts were then carefully placed so that they were all in line. It's important to spend time here getting everything lined up, it'll make mounting the coal rails easier. I made a jig to set the height of the rails. I say jig but it was really a strip of scrap brass filed to the required width, it could have easily been a drill shank of the required diameter.

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The brass rod is bent, checked and offered up etc etc etc. I didn't have any rod long enough to go all the way round, so there's a joint at the rear post. Couldn't decide whether this helped or was a hinderance. It took ages to get it looking right. Then I added all the boxes. The tool, sand and water filler boxes are all fold up etches. They are accurately etched but take a while and some care to get neat and square. Lots of the cast replacement ones I have seen are a bit crap, but maybe I would have saved a lot of person-hours by getting Mickoo to 3D print these items. Mick is one of the few people I'm aware of that does high quality, useable 3D printed parts.

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So there it is. (Sorry I couldn't be arsed to rebuild the loco for some publicity shots. It's partially stripped for painting.) It'd be with Crayons (or is it Felt-Tipped?) Haywood by now if our bloody Land Rover wasn't broken again!! More pics when it's reassembled post paint, but there's a few more construction pictures on my Flickr account here: nick dunhill
 

mickoo

Western Thunderer
You only had to ask ;)

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All ready had them done for the 2500G tender, think they're pretty much the same tool boxes.

I think the coal rails are D shaped section, on the Finney7 2500G they're a flat etch so that's what went on.

On the MoK Armstrong I think they were flat etch strip individually stuck on like yours but I opted for D section.

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The best D section I've found is from MetalClays4You and you need to get the brass stuff made from NuGold, it's the perfect tensile strength to remain straight once fitted and pliable enough to be bent around corners and tank top cut outs. I've only used the 'soft' version for coal rails and cab beading Jeweler's Brass Half Round Wire (Soft) NuGold | eBay

In hindsight maybe the half hard would be better option for coal rails as they tend to have more gentle radius and less convoluted profiles for which the soft is excellent to form with.

I use 1.0 mm for coal rails and 0.8 mm for beading, either tender tops or cab rear edges etc. Having said that, for LNER Pacifics then 1.0mm is better as their D shaped cab beading is quite chunky.

I buy it in 5-10m lengths which keeps me going for a while.
 
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