Split an STL in OrcaSlicer: cut, connect, print

What OrcaSlicer’s cut tool can do

OrcaSlicer started as a fork of Bambu Studio, which itself grew out of PrusaSlicer, so the cut tool will feel familiar if you have used either. It cuts the selected object along one plane, can lay each half on its cut face and adds connectors: plugs (a peg on one side, a hole on the other) and dowels (holes on both sides plus separate pins). Depending on your version, you may also find a dovetail option.

It is the right tool when a model is just over your limit: a bust slightly too tall for a K1C or SV06, or a helmet a little wide for a Kobra 3 or Centauri Carbon. Even a Voron 2.4 350 runs out of room for life-size cosplay pieces.

Cutting a model step by step

1. Load the model and select it. Try a rotation first: a long model often fits diagonally.
2. Press C, or pick the cut tool in the toolbar above the 3D view.
3. Move the plane by dragging its arrow, or type the height. Keep it level unless an angle hides the seam better.
4. For each half, choose whether to keep it as it is, place it on the cut face or flip it. Cut face down means a flat, support-free bottom.
5. Add connectors (next section), then perform the cut.
6. Press A to arrange. If the halves don’t fit on one plate, add a plate and move one half onto it.

Orca projects hold several plates, so you can keep every piece of a model in one project and slice all plates at once. Any piece that still exceeds the build volume can be cut again.

Connectors and a good fit

Switch the cut panel to connector editing, click on the cut face to drop connectors, then set type, shape, size and depth. Place them in thick, solid areas: a connector that breaks through a thin wall leaves a hole on the visible surface.

Dowels are usually the better choice because both halves keep a flat face to print on, and a broken pin is easy to reprint. Plugs avoid extra parts but stick out of one cut face, so that half prints cut face up or with support.

Fit depends on your printer’s accuracy. Orca’s calibration menu includes flow rate and pressure advance tests, and a well-tuned flow keeps holes from shrinking and pins from swelling. Then print our free tolerance test to find the clearance for a snug fit, and apply it in the connector settings or by scaling the pins. For removable assemblies, compare dowels and magnets.

Print settings for split parts

• Use one filament, one process profile and one layer height for every part, or the seam will show a change of texture.
• Set the seam position (aligned or back, for example) so the layer-start seam lands on a hidden side of each part instead of next to your cut line.
• Give parts with connector holes a few extra walls, so the holes don’t crack when you press pins in.
• Add a brim to tall parts standing on a small cut face.
• Dry-fit, glue, then fill and sand the seam. Our guide to gluing and finishing seams covers glues and fillers.

When a dedicated splitter is faster

Orca cuts one object with one plane at a time. Splitting a large model into a grid means repeating the cut on each piece, placing connectors face by face and tracking which of a dozen similar parts goes where.

SplitSTL plans every cut at once from your printer’s build volume, with presets such as the K1C, Kobra 3 and Voron 2.4, or a custom size. It reads STL, OBJ, 3MF and GLB, lets you move any plane, can shift planes toward thinner sections (smart cuts) and adds pins, pegs or magnet pockets on every face. Parts get engraved numbers and lie flat on their largest cut face. The download includes one STL per part, 3MF plates to slice in Orca, an illustrated assembly guide and a filament estimate. The preview runs in your browser and the first export is free.

Related: Bambu Studio, PrusaSlicer and splitting tools compared.