Oswestry Works

Locomotive works diorama in 4mm

Tag: whistles

Dukedog variations part I – No.9018

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With 5726 waiting on some final bits (smokebox number and shed plate) I thought I’d make a start on the trio of Dukedog’s that will feature in the works.  At this stage its detailing I’m concentrating on, converting them to P4 will be a challenge for later when I’ve developed some better skills…! There is a well documented process to convert a Dukedog to EM on Alan Gibson’s website, hopefully this could be a good starting point.

The 3 Dukedog’s will give some opportunity to model some of the slight variations between the class members as detailed by Russ Elliott on the GWR Modelling website.  Another great source is Railway Bylines Vol 16 issues 2 and 3 (Jan & Feb).  Both have 14 page or so articles on the life of the Dukedogs and some great photos. For the works I’ve selected first in class No.9000, No.9004 and No.9018, all 89C:

9000 (great reference photos at Dovey JunctionAberystwyth and Machynlleth)

  • Sandboxes above the footplate (determined by the particular donating Bulldog frame)
  • Top feed
  • No whistle shield
  • Small Dean/Churchward tender
  • Fluted rods
  • Lamp iron on smokebox door
  • Black background number

9004 (On shed at Portmadoc, in store at Wellington)

  • Top Feed
  • Short whistle shield
  • Fluted rods
  • Lamp iron on smokebox door
  • Red background number

9018 (On freight at Aberdovey, not long till the end, Oswestry)

  • Parallel buffers
  • Tall whistle shield
  • Red background number
  • Fish belly rods
  • Faded GWR shirtbutton motif on tender

Other options in the future might be 9005, 9014, 9017… can you tell I like Dukedogs… 🙂  Looking at the works registers for the period I’ll be modelling, there are plenty to chose from.

Works Entries - 9000 Class

9018 spent it’s last days in store out on ‘the batter’ siding at Oswestry.   Along with 9017 and 9004, these were the last of the Dukedog’s to see service in 1960.  I’d picked up a cheap Bachmann GWR Dukedog from Ebay with various parts broken or missing – the perfecting starting point for 9018 as most of the stuff which was missing I was planning to replace anyway!

First up are the buffers, I’ve used Alan Gibson parallel Collett versions.  I can’t say how easy or hard it was to get the original ones off – they weren’t on there in the first place! The remains of the old buffers are part of the chassis casting, so these were filed down slightly before fitting the replacements.

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Next was the electrical conduit for the ATC equipment – a small pipe routed through the cab front, down through and then along the running plate to the ATC kit under the front buffer beam.  This was a pretty straightforward task with some 0.4mm hand rail wire and some holes drilled in the cab front and the running plate.  Photos from a trip to the Bluebell to see 9017 in store helped with this.

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Next step, though probably a little early considering what else there is to do, was to fit the fine whistle and mounting bracket.  I’d printed this a few days ago after a couple of days of fine tuning the B9 Creator settings.  This is the finest detail I’ve got so far, though amazingly there is still some room for improvement looking at what others are achieving!   It’s fitted to a Comet Model’s long shield, part of the LS74 GWR detailing etch.

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That’s it for 9018 now until a few orders come in next week – I’m waiting on cabside numbers from 247 Developments and smokebox numbers from Pacific models. For 9000 and 9004 I’ve final samples of the 3D printed top feed and sandbox prints currently curing in the UV oven.  Both these designs needed some revisions as the first round of prints weren’t quite right.  The top feed was a pig to design, not having an diagrams to work from just photos, but I think I’ve got it somewhere near now.  Sandboxes are quite straight forward, there are 2 types, the more common type with the pull rods running along the top, and a less common variation with pull rods running along side the sandbox.

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Pushing the envelope with a B9 resin mix

GWR 9000 Class Top Feed test print

After what was in retrospect disappointing results with Spot HT – through my own ineptitude I must add, I went back to the tried and tested  1:1 mix of B9 Creator Red and Cherry resin.  This isn’t to say one is any better than the other, but with little life left in the layer of PDMS silicone before it needs replacement I didn’t have the leeway to experiment further with Spot HT.

This last batch of prints has been more experimentation with what level of detail is possible.  Second time round I reduced the size of the whistles and the steam heating cock to be a more prototypical size, even more challenging for the printer.  After quite a few false starts (left the projector lens cap on, build table not calibrated properly, not enough resin, ultrasonic died), I finally got a successful batch of prints of the highest detail so far.

This feels like uncharted territory because I’ve not wanted to let myself believe that it was capable of this kind of detail, until I’d seen it with my own eyes, coming out of my own printer.  I firstly revisited the design of the top feed for the Dukedog, the previous version not having a recess for the pipework.  This was designed to fit 20 swg copper wire, but the printed hole is slightly tight. It was a good exercise to see how well the resin could be worked with and the small hole could be opened up easily twiddling with a small drill bit.  This top feed will end up on 9014.

The whistles came out almost perfectly, considering that some of the detail in the design was under 0.25mm it would be impossible to see with out a macro lens or magnification.  Once cured these fine parts are quite robust, they aren’t indestructible but they did handle tweezers and finger tips, positioning them and trimming away traces of Tacky Wax under a magnifying glass!  It’s the detail presented on these that has really left me speechless.

GWR Standard whistles and mounting bracket test print

GWR Standard whistles and mounting bracket 30 micron xyz print

The beauty of this resin is it’s use to complement traditional materials, in this case matching up the whistles and mount with a Comet whistle shield etch and two strands of 36 swg copper wire to represent the whistle pipework.  The whistle print stood up to the finicky task of glueing everything together well, with impatient tweezer nibs looming, third hands full, trying not to drown the details out in glue.  This is the kind of detail I was hoping to attain after a few abortive attempts last year.

So with that done I think I’m out of excuses as to why 5726 can’t be finally painted and have its correct numbers fitted!

5726 with new whistle assembly

Comet Whistle Shield Etch, 36 SWG copper wire and 3D printed whistle and bracket assembly

5726 with new whistle assembly

5726 with new whistle assembly