OpenSCAD: a model written in code for 3D printing

How OpenSCAD works

OpenSCAD follows the principle of constructive solid geometry: you build a model from cubes, cylinders and spheres by adding, subtracting and intersecting. Everything is in a text file, so you can write dimensions as variables. Changing one value gives you a different box size, number of holes or wall thickness. There is more on Wikipedia too.

It is parametric modelling in its purest form. OpenSCAD is unsuitable for organic shapes, Blender is for that.

Export

After rendering (F6) choose Export and select STL or 3MF. The preview (F5) is enough for checking the shape, but export needs a full render. Units in OpenSCAD are dimensionless, but slicers treat them as millimetres, so 10 means 10 mm.

What to watch for

• Zero thickness. Two bodies that only touch along a face can join incorrectly. Give them a small overlap, for example 0.01 mm.
• Smoothness. The $fn variable sets how many sides a circle is made of. With a low value a cylinder will be faceted, with a very high one the file is needlessly large.
• Thin walls. Under 0.8 mm they do not print cleanly with a 0.4 mm nozzle.

OpenSCAD and your order

A typical use is a box with adjustable dimensions: you enter the length, width, height and wall thickness in variables, and the code produces the body, the openings and the lid. When you then need another size, you change the number. For small batch production that is practical: you can order several variants of one part at once.

You upload the file to the calculator. Thanks to the parameters you can easily create several sizes of the same part and order each with its own quantity. The price is calculated from the real preparation of the model for printing, so you see how the size affects grams and time.