MikeOxon

I agree entirely and usually follow the same plan. My concern was that the Geetech printer dealt with the small features far more successfully than the Prusa although th Prusa has fewer artefacts in the flat areas of the planking. I have accumulated quite a collection of BG 12 ton coal wagons in attempting to resolve the problem with various changes to the Prusa slicer settings. Now, I shall try using Cura and see how it goes - more wagons to come!!!

Thank you very much for that, Mike, I'll give it a try. I have been continuing to use the Geeetech while my last print head keeps going but replacements are no longer available.

Thanks njee20 but it was just an 'interesting' design to tackle, while I think about where I want to go next.

It' just that I like to try the quirky and unusual and see what challenges they throw up, when it comes to modelling them. As this was just an experiment, I have printed at only 0.15 mm resolution, hence the banding but, as you say, the printed vinyl will cover most of that, although in reality it's not at all obvious.

Perhaps it's related to the quotation on you 'signature' panel, Edwardian "Norfolk is cut off on three sides by the sea and on the fourth by the West Norfolk Railway" - E L Ahrons I think it was perhaps the colouring that give it the Transatlantic look

There's something about the buildings that gives Mumbling on the Hill an American or Canadian look.

Thank you, Mike. I often just use a 200°C soldering iron to 'weld' parts together but this was too delicate for that method.

Thank you Jason. this has been suggested by Prusa as a possibility. The trouble is that the same reel of filament prints well on my Geetech E180. It's a bit disappointing that the Prusa is causing me problems but I am forced to change because new print-heads are no longer available for the E180.

Background Several years ago – 2006 in fact – I was driving away from a visit to Blaenau Ffestiniog slate quarries and noticed that the last train of the day was due to arrive at the railway station. It turned out to be quite a long wait, as the train on the Festiniog Railway was in trouble and eventually arrived with a broken flexible steam pipe to one of the power bogies. With a sense of ‘make do and mend’, the trailing end of the pipe was lashed up and the train then made a very late start for Porthmadog, relying on just one power bogie for the downhill trip Broken Steam Pipe of ‘David Lloyd George’ At that time, my small model railway was in abeyance, although I did think briefly about the Langley Models kit, which seemed rather basic and also required the purchase of an American diesel to provide the chassis. Now, there is the Bachmann model, which looks very nice but, at £200, this is too expensive just to satisfy a vague whim. It’s too long anyway for my rather tortuous narrow gauge track around the North Leigh quarries. I did feel an ‘itch’, however, to try one as a 3D modelling task. I felt it provided an interesting challenge to lay out the components in such a way that they could be printed on my basic FDP printer. Steps to Creating My Model I found a drawing by Ian Beattie of a ‘typical’ Festiniog Double Fairlie in ‘Railway Modeller‘ November 1992, which I have used as a basis for my model. I also found a very helpful photo of an unclad ‘Merddin Emrys’ at Boston Lodge on the Festiniog ‘Facebook’ pages. This showed me several normally hidden details of the boiler and its supporting structures. The Footplate Following my usual method, I imported the Ian Beattie drawing, as a ‘canvas’, into Fusion 360. I started by extruding the footplate from the plan view in this drawing collection, as shown below. I designed this so that the top surface was completely flat and could be laid on the bed of my FDP printer Extruding the Footplate in Fusion 360 Since I do not have a practical application for this type of engine, I am treating it simply as a design exercise. The Cab and Firebox The next challenge was the central cab. Since I had included the parts of the sides below the footplate and the firebox plinth in my initial footplate component, I had to create a part that would sit flat on the firebox plinth. I first drew the front and back ends of the cab by tracing over the drawing. The sides were a little more complex, because of the ‘joggle’ in the width, at mid-height. I created a 1mm ‘offset’ drawing inside the edges of one of the end walls of the cab and then extruded this profile along the length of the cab to create both sides and the roof. I then drew the outline of the side opening on one side of the cab and used the ‘push-pull commend to cut out these openings through the entre width of the cab. These stages of my construction are illustrated in the following drawing: Steps in designing the Cab for my Model After the extrusion described in Step 1, my next Step 2 was to add the other end wall to the cab and then complete the assembly by adding a floor, which would sit on the firebox plinth, when printed. Step 3 shows the twin firebox, which was a separate extrusion and, as in the case of the cab, I drew the detail of the fire doors on one side of the box before using the push-pull tool to emboss the details of the two doors. I also added the shaft for the handbrake. Similarly, I added some details of the reversing lever on the opposite (Driver’s) side of the firebox. Step 4 shows the complete cab with the firebox inside, aligned over the footplate, which I had extruded first. Note that the large holes through the length of the firebox and cab ends are to allow a brass tube to be passed along the whole length of the printed model, to act as a ‘spine’, both to align the two boilers and to hold everything together. The Side Tanks The next challenge was presented by the four side tanks. Those on the Fireman’s side contain coal bunkers while, on the Driver’s side, there are tool boxes on top. These tanks form mirror-image pairs at each end of the engine. To create the tanks, I started by extruding from a rectangular base to the height shown on the drawing,. On the prototype, the tanks have extensions on their inner sides to fit around the boiler. I created these by drawing the end profile and extruding this along the length of the tank. I added the tank fillers by extruding upwards from the top surfaces of the tanks, after drawing their profiles. The coal bunkers were extruded in two parts: a rectangular base and the (initially) vertical plate behind the bunker. I then used the move tool to tilt the plate to the angle shown on the prototype drawing. After joining the two parts together I moved them into position on top of the relevant tanks (on the Fireman’s side) as shown below: Coal Bunker on Fireman’s Side Adding some Coal As an interesting exercise, I thought that I would try adding a simulated coal load by means of 3D printing. In a previous post I described how I used an extension to Fusion 360 to create a surface texture. This comprised a ‘plug-in’ for 'Fusion 360' called ‘Image2Surface’, which adds the capability for 'Fusion 360' to create a textured surface from a 2D image. Downloading the appropriate software and then getting it to work was not straightforward but, fortunately, I found a 'YouTube' video, which explains the procedures very well. In my previous post, I created a textured surface based on a photograph of gravel ballast. It occurred to me that the appearance was quite similar to that of small coals in a bunker, so I made a copy of my previously created texture and used the cutting tools in ‘Fusion 360’ to make a rectangular section to fit in the top of my coal bunker. The result is shown below: ‘Coal’ texture panel above my rectangular Coal Bunker. With appropriate colouring, I feel that the gravel texture provides a reasonable representation of the top of a filled bunker! There is an important caveat when creating surfaces by this method – they can involve a very large number of facets and vertices, which results in very large file sizes. Even though my model bunker top only measures 4 mm X 17 mm, the .STL file that describes it occupies a staggering 258 MB. Of course, I could easily reduce that size by reducing the level of detail but the act of ‘slicing’ the model for printing reduced the size anyway, to a manageable level. This is a technique to bear in mind for small applications but not really suitable for creating large areas of ‘facings’ on buildings and other scenery. The Boilers and Smokeboxes The two boilers are identical and are simple cylinders, formed in exactly the same way as I have described for many earlier engine models. Similarly, the boiler fittings and smokebox all followed my usual methods. Once I had brought all these parts together within the ‘Fusion 360’ software, my 3D model looked like this: My 3D Model of a ‘typical’ Double Fairlie Printing my Model As usual, I printed my model as a set of components, arranged so that each could be built up from a flat surface. With experience I have found that my FDP printer is far more tolerant of overhangs than I had initially thought. I now take more ‘liberties’ in the design and find that quite large openings, such as where the boilers fit into the cab ends, can be printed without any additional supports or ‘helpers’ I have previously printed smokeboxes as open tubes and added the curved front door separately. This time, I tried printing the smokebox as a single item and was surprised to find that my printer bridged the hollow centre behind the curved front without difficulty. I suspect that the ability to bridge gaps during printing depends strongly on the temperature of the filament when it is extruded. The largest single part was the footplate and I printed this ‘upside down’ on the printer bed, taking advantage of the extensive flat surfaces. Note the opening in the cab side, which is ‘bridged’ without any additional support. Footplate Model on the Printer bed Next, I printed the cab, which comprises the end and upper side walls, up to the level of the roof. Note that the lower side walls and a plinth for the firebox were included as parts of the footplate component. 3D-printed Cab, mounted on Footplate The holes in the cab end walls are to accept a brass tube which runs the length of the model and holds the boilers and smokeboxes in alignment. This tube also adds weight to the structure. I printed several of the smaller parts – sandboxes, domes, and chimneys – together as a group. They all printed surprisingly cleanly and despite the small contact areas remained firmly attached to the printer bed. This set of parts took just 12 minutes to print! 3D-printed Small Components For this model, I set the layer height when printing at the ‘normal’ setting (0.15 mm) rather than the ‘fine’ setting (0.10 mm) , which I use when there are rows of rivet detail or other detailed structures. This does mean that some ‘banding’ is visible in the photographs but is not noticeable at normal viewing distance on a 4 mm scale model. My complete set of parts after printing is shown below: 3D-printed Components of my Fairlie model The first step in assembling the parts was to place the twin-firebox unit within the cab. I then inserted the central rod and slid the two boilers and smokeboxes over this, to check the overall alignment – which was good. I used superglue to hold this partial assembly together. I have read in some places that superglue does not work well on PLA plastic but that is not my experience, provided it is given time to polymerise. In fact, I have sometimes found it difficult to separate parts that I have inadvertently not aligned properly! Adding the tanks came next. It’s important to get each tank in its correct position since they are all different! After a little trial and error, I found that the best method was to glue each tank to the appropriate end of the cab, ensuring that they were aligned correctly with the two boilers and that the tanks and cab all sat flat on a plane surface. 3D-printed Model with tanks glued to cab Once the bonds had hardened, I added the various small details – sandboxes, domes, and chimneys - by means of tiny drops of glue under each, then holding them in position for a few moments until the joint was firm. Finally, I could glue all this ‘upper’ structure to the footplate, which was rather flexible on its own but gained rigidity once glued to the lower surfaces of the tanks. The complete assembly then looked as below: My 3D-printed double-Fairlie model I have thoroughly enjoyed designing and constructing this model. Of course, the issue of the two power bogies remains! I intend to apply lining and lettering by means of printed vinyl overlays as described in my earlier series of posts about ‘lining and lettering’. Mike

I'm sure your workroom would have looked very nice in overall red oxide colour 😀

You've ended up with something reminiscent of 'Galloping Gertie', absorbed into the GWR from the MSWJR and numbered '24'. She is reputed to have taken an express from Bristol to Swindon, following the failure of 'King George IV'.

What time period are we supposed to be? Flashing indicators did not appear in Britain until mid to late 50s.

Perhaps Mr Price knows Mr M G Williams and could find out more?

This advert from 1899 may be of interest Mike

In the days before railways, cows for milk were often kept in quite small yards amongst the houses in towns - as were hens for eggs and a pig being fattened! Visitors to the SS Great Britain in Bristol can see the cowshed on the open weather deck, to provide milk during a voyage: Mike

I can remember, on a campsite in rural France in the 1960s, collecting milk in a jug from a cart rather like that one.

Don't forget the bicycling craze of the 1890s, when it briefly became fashionable for ladies to be seen cycling in Hyde Park and a whole new style of 'Rational Dress' appeared. There were also fulminations from some pulpits about the moral evils of ladies wearing bloomers 🤯

I tried enhancing the photo as well as I could and feel that the name on the splasher of the leading engine is more like to be Princess Beatrice than the other suggestions. I have seen several similar views taken near Hayes. See for example the collection at https://railway-photography.smugmug.com/GWRSteam-1/Dean-Locomotives/Dean-assorted-designs/Dean-Single-3031-class/i-v3DTVQH/A

My main reason for model-building is to be able to visualise some of these early engines 'in the round' 3-view drawings and posed photos can only tell us so much but the real 'character' of an engine often only becomes apparent when you can look at it from different angles. It's great to see No.34 coming through like this 😀

Your problem rang a faint bell with me. It may be something completely different but I recall that back in 2014 I had a problem with rounded corners when using Silhouette Studio v.3. When I reverted to Studio v.2, the problem disappeared. If you still have a copy of the older version, you might like to try it.

Thank you. I sometimes feel that my modelling interests have gone rather 'out on a limb', so it's good to know that that are still of interest to some people. Some of my subjects, especially the early engines were themselves rather 'fantastic'!

Thank you Mikkel. There was very little standardisation in the early days and wagons were built in small batches by several different makers. The early ones were all-wooden, built like farm wagons, but the GWR began to use iron construction in the 1850s. After that, the writing was on the wall for the broad gauge so very little new stock was built and a great mix of styles ended up on the Swindon dump in 1892. I assume that the Danes brought the word to Anglo-Saxon England, whatever its original source. That is the purpose for which I originally bought my set - they work very well at defining paint edges.

I agree - I feel that the whole point of these 'sims' is to see the trains actually moving 🙂

The ‘tilt wagon’ seems to have been a popular design in early broad gauge (BG) history but I hadn’t got round to building a model before now. A very few of these wagons were converted to standard gauge and I did model one of those back in 2014, regarding it as an interesting curiosity! In the early days, it seems that most goods (and 3rd class passengers) were carried in open wagons but a growing need for weather protection led to the addition of canvas covers, known as ‘tilts’ (from an Old English word ‘teld’ meaning tent). Hoops were fitted, to support the canvas, and some wagons had raised ends to provide a more enclosed structure. The late Eddy Brown collected information about these early wagons, which is contained in the Data Sheets available to Broad Gauge Society (BGS) members. A review of early BG wagons appeared in the BGS Journal ‘Broadsheet’ no 34 (Autumn 1995), including the following sketches by J.C.Bourne: Over the following years, many different variants of the same basic style appeared, produced by several makers, of wood or iron construction, most with 4 wheels, although larger ones with 6 wheels were also built. These wagons became very popular and were used for many different purposes, including carriage of livestock. Evidence of this usage is seen in the lime-washed wagons photographed in the Swindon ‘dump’ after the broad gauge ended in 1892. Overall, the following photograph shows that there was a great range from which to choose, for model-making! Broad Gauge Wagons at Swindon ‘Dump’ 1892 Several ‘standardised’ wagons, of all-iron construction except for a wooden planked floor, were built in two batches between 1853 and 1854 by various builders. The wagons were generally l7ft. long with side-doors. The inside width was either 9’ 9” or two inches wider. The wheelbase was 9’ 9” in all cases. They had 3’ long springs, set behind the axleguards, with 3’ 6” wheels and Normanville high-filler patent axleboxes. Drawing NRM 4832, below, does not show brakes but they may have been fitted at some stage. This old drawing is rather distorted but there is a better version in Alan Prior’s book ‘19th Century Railway Drawings’. Thus, I had the basis for constructing a model by following my usual method of copying over a printed drawing using ‘Fusion 360’ software. My 3D-model of an 1850s Tilt Wagon The chassis was a direct copy of the one I designed previously for my 12-ton coal wagon, of which the prototype was built to the same specification as the tilt wagons of the period. I had to lengthen the ends a little, to match the body of the tilt wagon, but this was a simple adjustment in ‘Fusion 360’. My 3D-model of the Underframe Although these wagons used smaller (3’ 6”) diameter wheels than the 4’ wheels of earlier versions, it was still necessary to provide apertures in the floor, for the tops of the wheels to protrude into wheel boxes. Printing my Model As I reported in my previous post, I am now using a ‘Prusa Mini+’ printer to create my models. As well as learning about the printer itself, I have been learning how to use the associated ‘Prusa Slicer’ software, which has several differences from the ‘Cura’ software that I used previously. ‘Fine Tuning’ the printer Fortunately, the printer itself is so smooth and quiet in operation that it seems to encourage experimentation, so I have been trying out various software settings in order to improve the performance, particular in respect of ‘stringing’ and ‘oozing’ of filament, as the print head moves between different areas of the print. Filament stringing around printed edges Although, when using my E180 printer, I frequently saw straight lengths of filament along lines where the nozzle had transited between different parts of a model, I have not seen this gossamer-like ‘fluff’ before and shall be interested to receive any comments from others who may have experienced this problem. It’s fairly easy to remove, by rubbing with fingers and an old toothbrush but, although I have reduced it considerably by adjustments to temperature and retraction distance, I have not yet eliminated it entirely. Tilt Wagon on Printer Bed before Cleaning I found that a useful tool for removing the ‘gossamer’, without damaging rivet detail, is a silicone rubber shaper, intended for controlling painted edges. Artists Silicone Colour Shaper as a Cleaning Tool Incidentally, during the course of my experiments, I suffered a break in the filament, as it loaded from the spool. The sensor, which I had bought as an optional extra for the printer, immediately detected the break and paused the print. The LCD screen displayed instructions for re-loading the filament and the print then re-started from where it had paused, without a hitch. Print ‘Quality’ Settings The layers of print produced by the Mini+ were noticeably more even than those from the E180. This very even-ness, however, made them more noticeable under close examination. At the 0.15mm ‘QUALITY’ setting for layer height, the layers are clearly visible in the close up photos below. There is also noticeable ‘trailing’ of filament around raised details. By changing to the 0.1mm ‘DETAIL’ setting in the slicer software, the printed layers blended together and, perhaps more importantly, the rivet detail was more cleanly defined. There is still a little ‘trailing’ but this is not noticeable under normal viewing conditions. These are unpainted surfaces with no additional surface smoothing after printing, apart from removal of the ‘gossamer’ referred to above. Close-up Comparison of Two Quality Levels Preparing the Model for printing I often like to break a model down into separate components, both to reduce individual print durations and to allow optimum positioning of components on the printer bed, to reduce the need for additional support structures. This particular model presented difficulties in adopting this approach, because there are very few flat surfaces, apart from the floor, while the ‘bonnets’ at the ends have substantial overhangs under the curved canopies at the top. I did initially try printing the sides and ends separately but it proved awkward to assemble the resulting parts neatly, so I thought I would risk printing the body all in one piece and see how well my new printer coped with the overhangs. I should not have worried, since the body printed cleanly and accurately. This, in the end, was by far the simplest and most satisfactory solution! There was still some fine ‘stringing’ of filament, appearing rather like spider webs between isolated structures, such as the ‘strouters’ (posts) that support the iron sides of the prototype. These fine strands of filament were easy to remove but I am hoping that further adjustments to the printing parameters will eliminate this minor problem. When I placed two models together, one printed with 0.15mm layer height and one with 0.1mm height, the quality difference is barely visible and would probably disappear under a coat of primer and a final coat of paint. There are still some whiskers of filament that need to be cleaned off before painting. Two models printed to different ‘quality’ standards There is a significant difference in the times taken for these two models to print. The 0.15mm resolution print took 1h 30m whereas the 0.1mm resolution tool 2h 40m. Whether this difference is significant depends, perhaps, on the overall size of the model and for small items such as these, I did not feel it was any hardship to adopt the finer quality. The following picture shows the complete model, with both body and chassis printed at 0.1mm ‘Fine’ quality. I have added wire rails between the ‘strouters’ or posts. My 3D-Printed Tilt Wagon + Chassis before painting Mike

For anyone interested, I did some experiments with different roofing methods, described in my blog, back in 2015