How to split a model for UltiMaker Cura

What Cura can and cannot do

Cura can scale, rotate, mirror and arrange models, and it slices very well. What it lacks is a cut tool: there is no built-in way to slice a solid model along a plane into two printable halves with connectors, as the cut tools of other slicers do.

That leaves three workarounds: sinking the model below the plate, trying a Marketplace plugin, or splitting the file before it reaches Cura. With an Ender-3 V3 SE (220 × 220 × 250 mm) or a Neptune 4 Pro, oversized models come up often enough to deserve a routine; even a K1 Max stops at 300 mm.

Workaround 1: sink the model below the plate

Cura only prints what is above the build plate. If you stop it from dropping models onto the plate, you can push part of a model below it and print just the top section.

1. In the preferences, untick Automatically drop models to the build plate.
2. Select the model, open the Move tool and lower it by the height you want to leave out, with a negative Z value.
3. Slice and check the layer preview: the first layer should start exactly where you want the cut.
4. For the other section, rotate the model 180° (rotate, don’t mirror) so the remaining part is on top, lower it so the cut height sits at the plate, and slice again.

Each cut face ends up perfectly flat on the plate. The limits are real, though:

• horizontal cuts only, in the model’s current orientation;
• positions you calculate yourself: the second lowering is the model height minus the first;
• no connectors, so the parts only butt together with glue unless you drill holes afterwards;
• no mesh is saved: Cura keeps the whole model, so there is no STL of each part to reuse or share.

Workaround 2: Marketplace plugins

The Cura Marketplace has plugins that add mesh utilities. Mesh Tools, one of the best known, focuses on checking and fixing meshes and on splitting a model into the separate shells it already contains. That helps with a file exported as several disconnected bodies, but it is not the same as cutting through solid material.

Before relying on any plugin for cutting, read its description, check which Cura versions it supports and test it on a simple model. Even a plugin that cuts will rarely add connectors, number the parts or lay them flat for you.

Workaround 3: split the file before Cura

The cleanest option is to split the model first and import the parts into Cura as ordinary STL files. Free slicers such as PrusaSlicer and OrcaSlicer have cut tools and can export the parts (see our PrusaSlicer and OrcaSlicer guides), which works well for one or two cuts.

For more parts, SplitSTL does it in the browser. Choose your printer (presets cover the Ender-3 family, K1 Max and Neptune 4 Pro, or enter a custom volume) and it computes the cuts so every part fits, lets you move the planes, adds pins, pegs or magnet pockets, engraves part numbers on the cut faces and lays each part flat on its largest cut face. You get one STL per part to drop into Cura, an illustrated assembly guide and a filament estimate. The first export is free.

Printing the parts in Cura

• Slice all parts with the same profile and material, so the surfaces match across each seam.
• Print each part on its cut face whenever possible: it is flat and needs no support.
• Test pin clearance once with our free tolerance test. If holes still come out tight, Cura’s horizontal expansion settings, including one for holes, can open them up slightly.
• Glue, fill and sand the seams; our guide to gluing and finishing seams walks through it.