Project 24 - Battledown Flyover #1 (preamble)

Having successfully completed my first Resin 3D print project I was considering what to create next. The thing about Resin 3D printing is its ability to produce miniscule, crisp details. This drives us to go the extra mile in model design. In particular, as far as railways are concerned - rivets. Yes, I have become a rivet counter! 

Within walking distance of my home is Battledown Flyover - The Gateway to the West. It carries the up line from Southampton whilst the Salisbury up & down lines pass underneath, at a slew.

Battledown Flyover by Sandy B, CC BY-SA 2.0,
via Wikimedia Commons

If I modelled this scene where could I put it? My railway room is overflowing with layouts. 

My Misterton model railway layout in its current form has existed since 2016, having evolved from an earlier incarnation dating from the 1980s with the station building and goods shed created in the 1970s! It is based on 1960s Crewkerne station in Somerset, England. It being a main line station with goods handling facilities. 

I realised that from an operational point of view it mainly gets used to run trains round and round for the enjoyment of grandchildren. Shunting and Goods Yard operations are as rare as hens teeth. This might be the time to replace it with the Battledown Flyover scene. It would be exciting to see a train running over the flyover whilst another passes underneath.

I am a bit hesitant abandoning a station scene but, I do have a small branch line layout that maybe could be placed somehow on the other side of the oval. I am not sure at this stage whether a new layout will come to fruition. But, a flyover model diorama is certain, if only to make use of my 3D printer and satisfy my creative soul.

I researched the web and books, gathering images of the flyover and visited it several times to photograph elements of it. When I saw the beast close up I was taken aback by its complex construction and use of riveted plate girders. So many rivets! Its construction is compounded further by the struts not all being the same design. Some have different form (why?) and width meaning each need to be tweaked or designed independently for the model. I'll answer that question in a future posting.

Ballast Cleaning Train - Part 19 (SLA Resin 3d Print Version)

 This is the final part for this project.

Matisa 3B5 Ballast Cleaning Machine (late 50s early 60s BR era)

Aerial view of the machine and its electric generator wagon

How they were coupled for travelling.
In operation the generator was coupled to the other
end of the machine and an electrical cable connected between them.

To the beginning of this SLA Resin Printed 3D model series.

Read about the SLA (stereolithography) resin 3D printer here.

Read about the FDM 3D printed version and its train here.

Movie below features the FDM 3D printed model and its train.

Ballast Cleaning Train - Part 18 (SLA Resin 3d Print Version)

Photo shows the cabins for both wagons and two other bits for the generator wagon after a spraying with black gloss car paint.

Why black for wagons that are to be finished in 1960s departmental yellow? Black is a common base for figurine painting as it enhances shadows caused by creases in clothing when overpainted to let the black through in places. The same principal is applied here except there is so little relief in these parts that shadows are minimal. Furthermore, I found that it changed the hue of the final yellow coating requiring multiple layers to recover. I will not use black for the remaining parts of this build. However, it was useful in simulating the rubber surround of the window panes that were revealed when the masking tape was removed.

It was really difficult to emulate the yellow colour of the prototype. The Railmatch 2304 I chose was far too yellow. My first approach was to tone it down with a white wash.  This made it too pale so I followed up with a brown wash that brought it as close to prototype as I could achieve.

There are seven components that are resin printed, including the chassis with all its levers, rods, axle boxes, leaf springs etc. printed as one piece. The railings are galvanised wire, the couplings Hornby, the wheelsets proprietary, the lights are ends of a biro ink tube with polystyrene gell glue infilled and the vacumn pipes are wire with thinner wire wound around. These could have been integrated with the chassis print.

Here is a comparison between the FDM printed model (background) and resin printed model (foreground).  For the uninitiated there does not seem to be much difference. But there is!

First, we may notice the colour change. The FDM paint finish is completely wrong having a green tinge. Next is a difference in equipment. I believe the resin model is more representative of the picture in the book and an early period photo I used for reference. The equipment on the other is based on a later version that was photographed in a yard awaiting scrapping.

Other notable differences where the resin printed model wins over FDM:

• No visible print layers
• Finer details e.g. axle boxes and leaf springs fully formed - as good as injection moulded. (For the FDM model I butchered a proprietary wagon and implanted its injection moulded axle box and leaf springs to achieve detail.)
• Sharper corners and edges
• Fewer parts

All the parts for the ballast cleaning machine have been printed and painted. Assembly next, which will be featured in the next blog posting.

To Part 19.

To the beginning.

Read about the SLA (stereolithography) resin 3D printer that I used here.

Read about the FDM 3D printed model here.