Oswestry Works

Locomotive works diorama in 4mm

Tag: dukedog

No.9000 – Back to Black

Considering the benefits 3D printing gives when tackling something like the top feed and sandboxes, there is still a good deal of traditional modelling required to integrate them into the model.  The sandbox pull rods have given me a few hours of amusement trying to solder them (mental note: now might be a good time to look into etching some!); the casing for the top feed pipe, where it runs up the side of the boiler, was equally challenging.  I’d originally tried used masking tape to replicate the thin metal that encases the pipe, but I didn’t get very good results.  Having some time away from the problem was what I needed and this morning I realised that tin foil would be perfect for the job.

Shaping tin foil around the top feed pipe

2 hours later I was still battling with the umpteenth strip of tin foil, having tried and failed with 3 different methods for accurately shaping it around the wire.  The final method which worked well enough was to bend some wire around another Dukedog boiler, take an inch long strip of tin foil about 2.5mm wide, tape one end to the boiler/wire and then smooth the tin foil down the wire making sure it shaped to the wire.   Then using a flattened end of a cocktail stick you can tease the tinfoil gentle into the wire.  Even at that stage the process is fraught with danger, as slightly too much pressure with the cocktail stick tears the tin foil.

Shaping tin foil around the top feed pipe

With that fiddly task completed I turned attention to the front of the loco.  No.9000 was one of a few class members that had a lamp iron on the smokebox door, another nice fiddly task to challenge me.  The lamp iron on the smokebox door would need to be quite fine so as not to jar with its surroundings, so I decided to use Shawplan Extreme Etchings Lamp Brackets as these are a lot finer than the Mainly Trains etch.   Iain Rice’s Etched Loco Construction was my guide for folding the etch into shape, not as tricky as I thought but still a testing task with the Hold’n’Fold.   To keep things the same I replaced the other lamp irons and for variation fitted a new smoke box dart.

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With those jobs finished the last task tonight was to mask and then coat with Halfords black primer.  This wasn’t quite as straight forward as with the Pannier as the open cab has fantastic detail which needed preserving.  A few layers of Tamiya masking tape did the job but for me it still takes a bit of a leap of faith when using maskol.  This time however I’m completely sold on it, it worked great used directly on the cab windows and peeled off easily after starting with a cocktail stick.

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Of course once the primer is on then the niggles start to show.  The top feed has an unsightly gap where it meets the boiler that I’d forgot to tackle, I think I’ll have to try some modelling putty and another coat of primer.  Anyways, that’s it for now, I’m waiting on the numbers still so No.9000 will go back into the queue.  I think it might now be time to blow the dust of the High Level Chassis for No.5726! I’m booked onto the Loco building course at Missenden in March, so I think making a start on the kit now would be good and I’ll take a Comet Manor and Mogul chassis’ to Missenden as I imagine they will be quite a lot harder.

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Dukedog variations – Sandboxes

No.9000 Sandboxes and Top Feed fitted

A number of the Dukedog’s had above footplate sandboxes as determined by the frames of the donating Bulldog.  No.9000 and No.9005 will feature in the Works, both of which had this particular trait.  There is also another slight variation, No.9000 and No.9005 had their pull rods above the filler lids, whereas 9008 had them running along side the sandboxes, in between the wheel splashers and springs (it’s quite hard to make out, but here is a picture courtesy of the GWSR)

This evenings task was seeing how the 3D printed sandboxes for 9000 and 9005 would fit.  I’ve had to tweak them a few times to deal with the slight lip on running plate near the rear wheel splashers.  First job though was to remove the front sandbox lids from the running plate.  These are part of the metal chassis and were not going to budge with a knife, so I threaded a piecing saw blade between the boiler and the running plate in order to cut them away.

Removing the sandbox lids

First complication was that the front grab rails needed removing in order to get a decent cut.  These are also metal and quite hard to remove cleanly, in fact I only successfully pulled one, with the other three snapping off and leaving the peg in the chassis.  After taking off the sandbox lids I redrilled these ready for fitting replacements.

The sandboxes ping off their build supports really easily, but they do need a little cleaning up with a knife or needle file to ensure a flush fit.  The build support penetration can be configured, in this case it was set to 25 microns, so if you remove the supports carefully they just need a quick once over with a file.

I’ve experimented with what angle to build them at quite a bit, the best detail being printing them in the normal orientation, but this does mean the base of them is rather uneven – this is due to the resin dripping away and some of it curing.  I’m sure that can be resolved, once I replace the layer of silicone in the printer I should get even sharper prints.  But for the time being I’ve rotated the prints 45 degrees which gives best of both worlds.

Dukedog Detailing Parts

On the top of the sandboxes I’d added the short spigots for the pull rods to connect to, more as a test if anything to see if the printer would cope with them. It did, but in practice they are useless, there is nothing for the pull rod to attach to and its too fine a point for glue.  These were clipped off and 0.4mm handrail wire used instead, allowing the brass strip pull rods to be soldered to the handrail wire.

Fitting 0.4mm brass spigots

Sandbox pull rod fitting

With that done the next jobs were to bring No.9000 up to the same basic detailed level of No.9018 – replace all the buffer beam fittings, add the ATC electrical conduit etc.  The top feed also needed fixing and the pipework modifying, all tasks which involve a fair bit of handling and not ideal after just fixing the sandbox pull rods!  Next time round I’ll put them on last as the pull rod connection to the spigots is quite delicate.

No.9000 Sandboxes and Top Feed fitted

No.9000 Sandboxes and Top Feed fitted

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

Missenden Abbey 3D Printing Course

I’m fresh back from attending Missenden Abbey’s Autumn weekend with a few test 3D prints.  8 of us took up the 3D Printing course which was running for the first time, involving an introduction to Sketchup and then as much 3D printing as you could fit in!   The course was self paced so worked will with the variation in knowledge of Sketchup, with people being able to help each other out as they progressed through the course material.  Having 3 printers between 8 of us also ensured there wasn’t too much waiting around for your turn on the printer.  It was a great weekend, with so much else going on in the other rooms as well.  I was able to drag myself away from the 3D printer for a half hour or so to see Kevin Wilson demonstrating soldering and having a bit of hands on myself.  I’d highly recommend the weekend, not only was the modelling good, its a nice place to spend a weekend with good food and good company – being able to put some names to faces and chat to some of the best in the field was great.

My aims were to improve my abilities with working with some of the solid tools in Sketchup and creating complex shapes such as fillets and bevels, along with getting an understanding of how 3D designs need to be engineered with 3D Printing in mind.  Such as taking into considering overhangs, bridges etc, by either using support material or printing in multiple components.  Here’s some examples of what was produced:

GWR 9000 Class 4-4-0 ‘Dukedog’

I’m interested recreating some of the subtle variations between the many Dukedog’s seen on the Cambrian (as superbly researched here on the GWR Modelling site).  These 2 items were good first steps to try out with the printer – above footplate sandboxes (as per 9000 and 9005), tall top feed (9021, 9004, 9000 and many others).

Sanboxes

Top Feed

The sandboxes were straight forward enough, taking the sandbox and wheel arch/splasher measurements from J.H. Russell’s Pictorial Record of Great Western Engines.  The top feed was a tougher to get right and I’m still not 100% happy with it, but it was a good test of skills using the follow me tool in sketchup.  I’d not been able to find any drawings of it before hand so it was a best guess from photos and drawings of other top feeds.

Craven Crane Hoist

This is part of the Erecting Shop crane that I have on my list of things to do for the works.  It’s a little early days to be thinking about detailing the works interior but this was a good chance to see what the printer could do.  I’ll need to revisit the 3D Design later to get it right, but this wasn’t a bad first pass.  I’ve roughly modelled the crane within the erecting shop to get an idea of scale as I’ve no drawings to work from, just photos from the surviving crane at MOSI.

Hoist

Craven Crane

GWR Manor Chimney

Lastly, by far the hardest task was attempting a chimney.  I’ve been looking for a BR-era Manor chimney for about a year, the DMR model seeming to be the best production but they are very hard to find.  Next best option has to be printing my own!  Find drawings however has been a challenge, I had a quick look at the NRM but didn’t have enough time for a thorough search.  This drawing is based on the GWR Chimney (loosely!), but it was more of an exercise in learning how to make the complex curves and shapes as the chimney meets the smokebox.  After getting a headache from trying to get this to work natively with sketchups toolsets, I had to use a plugin after reading this post on RMWeb.

Manor Chimney

Finally, here are all the bits printed out!  They were made using a MakerBot Replicator 2.0 at 200mn resolution.  They certainly have given me an idea of what is possible and more importantly got me thinking about how things need to be made in order for them to be printable.  I’d already taken the plunge and bought a 3D printer before doing this course.   After reading up and also seeing Rab’s achievements with his printer, I bought a B9 Creator 1.2.  The 1.2 B9 is capable of 30mn resolution so my first job will be reprinting these pieces as a comparison.   I’ve bought the kit version of the printer and haven’t started the build as yet, I’ve another course on Monday evening at the B9 distributors in London, I think it best to go there first to see one in action before making a start.

Missenden Abbey - 3D Printing Course