How to send a model for 3D printing

STL is the most common format and is perfectly fine when the model is finished. It records only the surface, as a mesh of triangles — no memory that something was once a circle or a thread, so it's hard to edit. If the model is final, that doesn't matter.

STEP is the better choice for technical parts because it keeps real geometry: we can change a hole diameter, add a fillet or adjust a dimension without remodelling. 3MF carries geometry, colours and settings in one file and is increasingly common. OBJ works for textured objects. Not sure? Send what you have — we'll recognise it.

Walls that are too thin. Anything under roughly 1 mm can't be laid down reliably — on the model it looks like a surface, in reality it falls apart. If the part has thin ribs or fine relief, tell us and we'll thicken them.

An open mesh. The model has to be a closed solid, with no holes or overlapping faces. Plenty of files downloaded online or exported from sketching software aren't — we repair them routinely, but it's worth knowing the step exists.

Wrong scale. This is the most common and most expensive mistake: a model exported in inches or centimetres arrives ten or a hundred times too big or too small. Always write one key dimension in the message — “height 84 mm” saves both time and material.

That's the most common case and it isn't an obstacle. A photo of the object from a few angles, a paper sketch with measured dimensions, or even a description of what's needed is enough to start. If a physical part exists — especially a broken one — we can scan it and rebuild it. The model that comes out of that is yours to keep.