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MOST RECENT UPDATES:

* Building the LMS Stanier Black 5

* Build GWR dia. AA11 "Toad" from a kit

* Machining Steel Wheels

Open SCAD

This is script based CAD design "language". It is about as hard to master as "BBC Basic" although it borrows from "Pascal" in its methodology. This is a good thing as both are "teaching languages". The former teaches how to write simple programs, the latter teaches how to make simple repeatable modules. It is freely available under GPL in Win, MACOS and Linux versions. OpenSCAD is used to design the object to be printed and to generate the .STL file from the script. This then is used by the production software.

Theory...

In the centre of a world that is 512mm high (+/- 256), 512mm wide (+/- 256) , and 512mm long (+/- 256), exists the point (0,0,0) from which all things are measured. The script allows for a few "primitives" from which everything can be made.

CUBE This means a rectangular shape.

CYLINDER This means a cylindrical object -can be a cone, frustrum, or cylinder.

SPHERE This means a shape made only of curves -can be smartie, zeppelin or sphere.

POLYHEDRON This means shape with hard edges- can be prism, pyramid, duodecagon etc.

thus;

cube(10,10,10); creates a cube that is 10mm x 10mm x 10mm.

The command TRANSLATE moves the origin point of the object.

thus;

translate(100,0,0)

{

cube(10,10,10);

}

produces an identical cube that is 100mm to the right of the initial cube.

The following script produces a "Stop Lamp" made from a cube, a cylinder, and a sphere.


//base of lamp

cube([10,10,10]);

//top of lamp

translate([10,5,0])

{

        cylinder(10,5,5);

}

//lamp bulls eye

translate([5,5,10])

{

    sphere(4);

}

The command UNION sticks all the commands together under one name that can be referenced by other scripts. Thus having written the commands for a Stop Lamp. union(stoplamp) will enable you to stick a stop lamp on any future script by simply telling it to stick a stoplamp THERE. In this case at the top of the five barred gate for my level crossings. The command MIRROR produces the mirror image of the union(5bargate) thus rhs and lhs...


Currently I am using Open SCAD to design "lego bricks" to build the station walls from. You are welcome to use the files in your own copy of Open SCAD. As it runs on several OS I will simply provide you with the text for you to cut and paste from. By all means feel free to add subtract or mangle the code to your hearts content!!!

To give you an example of what can be done with these files here is a shot of the partially constructed Station Frontage. All of the parts have been printed from the scripts in the text file above.


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Page last modified on January 20, 2018, at 02:27 PM