3D Printer FYIA 3MF can carry a model, but the file extension doesn’t tell you whether it also carries a slicer’s settings, modifiers, or an already-generated toolpath. Before you replace a project with an exported copy, find out which parts of the file you’re keeping. The department has supplied a tetrahedron for this purpose. It has four faces and no opinion about your slicer.
Import and change one thing
- Download the 20 mm fit specimen, an original geometry-only fixture released under CC0. Keep the original file.
- Open the 3D Print Inspector and drop the 3MF into Open local files. The model view should show a 20 × 20 × 20 mm envelope and four triangles. The file declares millimetres; you don’t need to infer units from the filename or the shape.
- Choose Scale, enter 200%, then Done. The envelope should now be 40 × 40 × 40 mm. Undo returns it to 20 mm; Redo restores the edit. This changes the working copy in the browser.
Export a model, then make a toolpath
Choose Export copy and select 3MF. Open the downloaded file in the inspector. The scaled geometry and millimetre units survive. The original title metadata does not. The downloaded archive contains the content type declaration, the relationship file and a model file. It has no slicer settings or G-code. This was a model-only export, even though its filename ends in the same three letters.
With that copy loaded, open Slice and run the default Community Bambu A1 profile. Use Inspect layer toolpath to view the layer-motion preview. The printer G-code download is a separate file with machine start and end commands. In our test, the 955-byte original produced a 1,080-byte model-only export and 460,563 bytes of G-code. These are the observed file sizes for this specimen and profile, not typical sizes or a performance guarantee.
| Artifact | What this test establishes |
|---|---|
| Original 3MF | Millimetre geometry and original title metadata remain available. |
| Exported 3MF | The scaled mesh opens at 40 mm; the original title and a slicer project are not carried forward. |
| G-code download | The browser slicer generated commands for the selected profile. A preview and a downloadable file do not establish a successful physical print. |
When to go back to your slicer
Use this workflow for inspecting geometry and preparing a separate copy. Keep your original slicer project when you rely on modifiers, support painting, or process settings. Reopen it in the slicer that made it and verify its settings and preview before printing. The tiny fixture above does not test preservation of those features, and the generated G-code was inspected in software, not sent to a printer.
The 3MF Core Specification defines the package and model structure. To understand why a toolpath can look wrong when a preview loses track of an earlier command, read Your G-code has a memory.