Wednesday, 17 June 2015

Road bridge railings

I have now used the 3D printer to create a scenery component for my Scalextric layout :-)


Where the Scalextric track crosses a bridge I wanted to have as much visibility as possible.

A stone wall would have looked nice but it would block out the view.  It would also be impractical in the real world because there would not be enough height to have a stone arch to support the span. Although the layout does not have to be realistic the scenery always looks better to me if it could exist and support itself in the full size world.


I decided to opt for a modern bridge style with an implied concrete and steel support structure and the thin metal railings being the only thing on show.

The railings are very easy to look through, which is what I wanted. The drivers can still see the curve of the lower level road just before the cars go under the bridge.

I could have made them from odds and ends but I now have a 3D printer so this was a chance to try something out.


The design was fairly easy to work out. Created in Blender, as usual.


I made minor changes to the design to suit 3D printing. The fronts of all the rails are level with each other. This allowed them all to lay flat on the bed for printing.

The first attempt at printing was a failure because, even though I had positioned the barrier on its front, the posts still overhung in mid-air.


I re-imported the model and selected the option to print support structures, for the second attempt. These are finely printed extra bits automatically added by the Cura software to support overhangs.


This worked very well but obviously requires a little bit more cleaning up afterwards.


Some of the details are a bit fine for the normal print quality. This took just under 2 hours. If I wanted to fix that I could either thicken up the fine edges or print using the fine or ultra fine modes but that would take a lot longer to print.

TIP: A thickness of 1mm is too fine to guarantee to print using the normal detail level. 2mm thickness prints out perfectly on the normal quality level so somewhere between 1mm and 2mm is the smallest detail for this setting.


I was very impressed by how easy the automatic support structures were to remove from the finished print.



In place on the track, the railings look exactly as I intended.


Another success.


Downloads

Blend file
STL file
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My designs on YouMagine.com

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