Guides

Preparing a file for 3D printing: SolidWorks, Fusion, Blender

Format, units, closed mesh, wall thickness: what our online quote checks in your file, and how to export it from SolidWorks, Fusion or Blender.

  • 01By the BUSE workshop, Agadir
  • 02Published October 2, 2026
  • 03Updated October 2, 2026

Export an STL, OBJ, 3MF file, in millimetres, describing a closed volume of at most 256 mm per axis, under 50 MB, with walls of at least 0.8 mm. Those are the checks our quote runs on every file, and a file that passes them is priced in a few seconds.

The prices and limits quoted in this guide are read from our quote engine when the page loads: they are what an order pays today.

What the quote checks

The checks run on every file you send
CheckLimitIf the file fails
FormatSTL, OBJ, 3MFA STEP or native file (SLDPRT, F3D, BLEND) is not read: export it as a mesh.
File size50 MBLower the mesh resolution on export.
Part size1 to 256 mm per axisToo large: scale it down or cut it into several parts. Too small: check the units.
Closed volumeNo holes in the meshThe part cannot be priced automatically: repair the file or ask for a manual quote.
WallsAt least 0.8 mmThe quote goes through, but thinner walls do not come out cleanly.

Units, the first cause of error

An STL or OBJ file does not say which unit it was drawn in: it holds only numbers. Our quote reads them as millimetres. A part drawn in inches therefore arrives 25.4 times too small, and a part drawn in metres a thousand times too small.

The 3MF format declares its unit, which makes it the safest choice when your software offers it. Either way, look at the dimensions the quote shows under the file name before ordering: that is the size that will be printed.

Exporting from SolidWorks

  1. Open the part, then File > Save As, and pick the STL type.
  2. In Options, set the unit to millimetres and the resolution to Fine.
  3. For an assembly, save each part to its own file, unless the whole thing is meant to print as one block.

Exporting from Fusion

  1. In the browser, right-click the body to print, then Save As Mesh.
  2. Choose 3MF or STL, millimetre units and high refinement.
  3. Export one body per file: two overlapping bodies in the same file give a wrong volume.

Exporting from Blender

Blender works in metres by default, and the STL export writes the numbers as they are: a 50 mm object is worth 0.05 there and arrives tiny. Fix that before exporting.

  1. In the scene properties, set the length unit to millimetres and the unit scale to 0.001, then check the object's dimensions.
  2. Apply the object's scale and modifiers, so the file holds the shape you see.
  3. File > Export > STL, exporting the selection only.
  4. Enable the 3D Print Toolbox extension: it reports non-manifold edges, which are the holes in the mesh.

What is a closed volume?

A printer lays material inside a shape. The file therefore has to separate an inside from an outside without ambiguity: every edge of the mesh must be shared by exactly two faces. A model made of surfaces with no thickness, a missing face, or objects simply pushed into one another do not meet that condition.

  • In CAD, work in solids rather than surfaces, and combine the bodies that are meant to be one.
  • In polygon modelling, close the holes and merge duplicate vertices.
  • Before sending, open the file in a slicer: most of them flag an open mesh.

Several parts, one order

Send one file per part and set the quantity on the quote instead of duplicating the part inside the file. Put all your parts in the same order: the start-up is charged once per filament (material or colour) loaded and delivery once per parcel, as the guide How much does 3D printing cost in Morocco shows.

If the quote still refuses your file

The quote shows the reason and a “Request a manual quote” button, which passes the file to us. We study it by hand and come back to you. You can also describe the project directly on the Custom project page. And if you do not have a file yet, see 3D printing without a printer.

Read next

The exact price is the one for your file

Drop it in: the delivered price shows in a few seconds, with no call-back and no waiting.