Split an STL in PrusaSlicer with the Cut tool
PrusaSlicer’s cut tool makes a clean cut with connectors without leaving the slicer. Here is the workflow, the options worth knowing and the point where a splitter saves time.
Before you cut
Check how far over the limit the model really is. A MK4S prints 250 × 210 × 220 mm, a MINI+ 180 mm in every direction, a CORE One 250 × 220 × 270 mm and an XL 360 mm. Sometimes a rotation is enough: try the model diagonally or on another face first. Our free STL viewer shows the dimensions and which printers a file fits on.
Then decide where the seam should go: a flat area, an edge, or a natural break such as the joint between a figure and its base. A cut through a face or fine detail is hard to hide later.
Cutting step by step
- Select the object and press C, or click the cut icon in the toolbar on the left of the 3D view. A cut plane and the cut panel appear.
- Drag the plane’s arrow or type the cut height. Tilt the plane with the rotation handles only if an angled cut really helps.
- For each half, choose what happens after the cut. Place on cut lays that half on its new flat face, which is usually what you want for printing; you can also keep it as it is or flip it.
- Leave Cut to parts unchecked to get separate objects you can print one by one (see the FAQ below).
- Add connectors if needed (next section), then perform the cut.
- Press A to arrange the bed. If the halves don’t fit together, print them one after the other.
A half that is still too large can be selected and cut again. The place-on-face tool (F) lets you print a part on any other flat face.
Plug, dowel or snap connectors
In the cut panel, add connectors, click on the cut face to place each one, adjust, then confirm. PrusaSlicer offers plugs and dowels, and recent versions add snap connectors:
- Plug: a peg on one half, a hole in the other. No extra parts, but the peg stands proud of the cut face, so that half cannot sit on it without support.
- Dowel: holes in both halves and a separate pin added as its own object. Both halves keep a flat face to print on.
- Snap: a plug shaped to click into its hole, for assemblies you want to take apart, as long as the material is not too brittle.
Set the shape, size and depth so each connector sits in solid material, away from thin walls and edges. Printed pins rarely fit holes of the same nominal size: use the tolerance settings if your version has them or scale the dowel down slightly, and measure your printer’s clearance once with the free tolerance test. For removable builds, see also dowels vs magnets.
Printing and assembling
- Use the same print profile, filament and layer height for every part so the surfaces match across the seam.
- Print pins lying down when you can: an upright pin tends to snap along its layer lines.
- Dry-fit, sand any high spots, then glue. CA glue is quick on PLA; epoxy fills small gaps and suits large parts.
- Fill what remains of the seam line and sand it; our guide to gluing and finishing seams goes through it.
When a dedicated splitter is faster
PrusaSlicer cuts one object along one plane per operation. A model that needs a grid of cuts means cutting, re-selecting and re-cutting every piece, placing connectors face by face and keeping track of a dozen look-alike parts.
SplitSTL does that as one job. It takes STL, OBJ, 3MF or GLB, computes the cuts from your Prusa printer’s build volume and lets you move any plane. Smart cuts shift planes toward thinner cross-sections, and a Pro mode cuts at natural joints such as a neck or a base instead of a straight grid. Every cut gets pins, pegs or magnet pockets and an engraved part number, and each part lies flat on its largest cut face. You download one STL per part, 3MF plates to open in PrusaSlicer, an illustrated assembly guide and a filament estimate. The first export is free.
See also the guides for Bambu Studio and OrcaSlicer, and how to print an object bigger than your printer.
Frequently asked questions
Where is the cut tool in PrusaSlicer?
Select an object and press C, or click the cut icon in the toolbar on the left of the 3D view.
What does Cut to parts do?
It keeps the cut pieces as parts of one object instead of separate objects. That is useful for giving regions different settings or filaments. To print the pieces separately, leave it off.
Which connector should I choose?
Dowels for glued assemblies, because both halves print flat on their cut faces. Snap connectors for something you want to take apart. Plugs if you would rather not print separate pins and can print one half cut face up.
Can PrusaSlicer split a model into a grid automatically?
No. Each cut is one plane on one object, repeated for every piece. For many parts, a splitter that plans the whole grid at once is faster.