1925 4 Sub

[Guest]

3D prints just in from CW Railways for the latest project - a Soutern Railway 1925 bull-nosed suburban electric unit similar to the one preserved at the National Railway Museum.

 

In 1945/6 these units were augmented from 3 to 4 cars with ewly built 10 compartment trailers.  Most of these were of the ‘1941’ type with the characteristic Bulleid/Lynes wide-body profile but conventional steel panelling on wooden frames.

 

I am using this car as a prototype for a potential new series of 1946-type all-steel units - the issue being, can one successfully use 3D printing to produce curved bodysides that are thin enough to allow almost flush glazing yet robust enough for normal assembly and handling?  The printed sides certainly pass the thinness test - at 0.5mm they are translucent - but it remains to be seen whether they are too eggshell-thin.

 

Previously I had designed an experimental side with thicker cross sections above and below the windows but this bent like a banana, admittedly after I had left it lying in full sun.  The new bodysides have lighter internal reinforcement in a matrix pattern that is intended to produce a more equal balance of horizontal and vertical strength.  We shall see whether this works - if not, the next step will be to increase overall thickness slightly.

 

If I can get the bodysides right it would open the door to a whole series of projects - 1946-type all steel 4 Sub units, a ‘Tin Hal’ and the SR-type EPB family.  The Eastleigh production line was turning out these units right up to 1959 using reclaimed underframes from pre-war electric stock.

 

[Siberian Snooper]

Looks very promising!

 

 

[Guest]

I should make it clear that the bending of the experimental side had everything to do with my design and nothing to do with Tim’s 3D printing!

[rue_d_etropal]

that is one design I have done myself.

http://www.rue-d-etropal.com/3D-printing/3d_printed_sg-trains2-southern.htm#sr-lswr-reb-3sub

[JCL]

On 18/11/2020 at 11:39, 34017Ilfracombe said:

I should make it clear that the bending of the experimental side had everything to do with my design and nothing to do with Tim’s 3D printing!

 

It's easily done - and I'm saying that from experience.

 

Those sides are very crisp and smooth, do you know what it was printed on?

[Guest]

I don’t know much about the printing process but there are some details on cwrailways.com and Tim can probably give you more information - suffice it to say that I am very happy with the quality of the prints.

I was concerned about the very thin sides of my prototype for the Southern’s postwar suburban fleet but it has worked out well:-

 

Edited December 6, 2020 by Guest

[KeithHC]

That looks great I can see the 4SUB coming very soon. Well done looking forward to your progress. I am starting out on the 3D design and print eventually I want to have a go at a few EMUs and a certain DEMU that will never be massed produced.

 

Keith

[Guest]

The 1925 Sub with its 1945 augmentation trailer is finished (apart from number decals still to be applied) and running on my layout.  Overall, I am pleased with the result, which seems to capture the bull-nosed character of the original, though the photos below show that my spray painting skills still have some way to go.  The "layer" effect of the 3D printing seems far more obtrusive in the photos than it is in reality - I guess it has something to do with the way I lit the model.