How to Cut a 3D Model in Half with Cura: 1 Minute to Split Your Design for Better Printing

Cura, the popular 3D printing slicer, doesn’t feature a native “split model” tool. However, with a clever workaround, you can still cut a 3D model in half for purposes like printing oversized models in sections. Here’s a step-by-step guide:

1. Import Your Model: Open Cura and load your STL or OBJ file.
2. Use Settings to Cut:
3. Orient your model so that the cut you want aligns with the build plate (e.g., for a horizontal cut, lay it flat).
4. Select "Per Model Settings" (right-click your model or use the left toolbar if enabled on your Cura version).
5. Choose Add Modifier → Box. Scale, position, and resize this box to cover the side you want to keep.
6. Set the box as “Mesh type: Cut” or, in older Cura, as a “modifier mesh”, and pick “Intersection” or “Negative volume” as appropriate for your version.
7. Preview the slice. Only the portion within the modifier mesh will be printed. For the other half, repeat the process with the modifier box covering the opposite side.
8. Slice and Export: Slice the newly cut model and export as G-code for each section.
9. Alternative Method: Use Third-Party Software: If Cura’s modifier meshes aren’t flexible enough for your needs, software like Meshmixer or Blender lets you cut models with far more precision. Slice in the external app, then import back into Cura.

As a designer, I always recommend testing the fit digitally if you intend the two halves to snap or glue together post-printing. Accurate “cutting” not only helps with 3D floor planning and visualizing room layouts, but ensures the structural integrity and usability of complex parts.

Tips 1:

After cutting your model, consider adding alignment markers or dowel holes so the two halves fit together seamlessly. This is a trick commonly used in professional prototyping and helps with both assembly and final appearance.

FAQ

Q: Can I split a model into more than two parts in Cura?

A: Directly in Cura, you’re limited by modifiers, but you can combine multiple boxes to isolate more sections. For advanced splits, tools like Meshmixer or Blender are recommended.

Q: Will supports generate correctly after cutting the model in Cura?

A: Yes, after slicing and keeping only half the model, Cura will auto-generate supports as needed for each piece.

Q: Do I lose detail if I use Cura’s method versus external software?

A: The detail remains, but external software allows for more precision and complex cutting planes.

Q: Is there a risk of the two halves not fitting well after printing?

A: Minor misalignments can occur due to printer tolerances. Adding dowel holes or alignment features helps with proper assembly.

Q: What’s the ideal orientation for cutting a model in Cura?

A: Position the cut so the flat side lies on the build plate, minimizing supports and improving print reliability.