How to split an STL file in Orca Slicer

By the splicestl team · Published May 15, 2026

Published 2026-05-15 · 5 min read

OrcaSlicer is a community fork of Bambu Studio (which itself forked PrusaSlicer), now maintained as one of the most-installed open-source slicers. Like its parents, Orca includes a built-in Cut tool, and like its parents that Cut tool is single-plane: you draw one slicing plane, the model splits into two halves. Orca's Cut also generates alignment dowels at the cut, similar to Bambu Studio.

This article walks through Orca's Cut tool, what it can and cannot do, and shows the multi-axis alternative for the very common case where you need more than one cut — for instance when a single sculpture is bigger than your build plate in two directions, or when you want real press-fit joinery rather than just dowels.

Finding the Cut tool in OrcaSlicer

Open OrcaSlicer, drop your STL onto the build plate, and either:

• Press C on the keyboard (the default shortcut), or
• Click the model to select it, then click the Cut icon in the left toolbar — it's the icon that looks like a horizontal line through a cube. Orca uses the same toolbar layout as Bambu Studio, so if you're familiar with Bambu Studio's Cut, this will look identical.

The cutting plane appears as a horizontal blue plane intersecting your model. Drag the plane up or down with your mouse, or type an exact Z value in the side panel. You can rotate the plane onto any axis (X, Y, or Z) by clicking the axis-aligned cube widget at the top of the panel.

The Cut tool's options

Once the cutting plane is in position, the side panel exposes a few options:

• Keep upper / Keep lower. Toggle either part on or off — useful if you only want to keep one half of the model.
• Cut to parts. Both halves are kept as separate objects after the cut, ready to print side-by-side on the build plate.
• Connectors. Orca generates short cylindrical alignment dowels at the cut plane, embedded so half pokes into each piece. After printing, the dowels slide into matching sockets so the halves register at glue-up. Default dowel diameter is 5mm and shape is cylindrical; you can switch to a hex or rectangular profile.
• Connector size and depth. Adjustable per dowel. The depth determines how far the dowel intrudes into each half.

The connector feature is similar to Bambu Studio's. It is alignment-only — the dowels are not press-fit, they're glue-and-align. If you want the pieces to snap together without glue, you need different joinery.

What Orca's Cut tool can do well

Orca's Cut handles the common case perfectly: you have a single solid model that is just barely too tall, and you want to cut it in half once, glue it together, and move on. Three minutes from open to sliced. The alignment dowels keep the halves true while glue cures, so you don't have to hold them perfectly in registration.

It is also excellent for the case where you want to print a model in two pieces specifically to orient each piece optimally — for example, cutting a head off a figurine so the head prints face-up (clean face) and the body prints standing (clean base), and the cut is hidden in the neck.

What Orca's Cut tool cannot do

The same limits that apply to Bambu Studio's Cut apply to Orca's:

• Single plane only. One cut per pass. If your model needs to be cut into a 2×2 grid, you have to run Cut, then Cut again on one of the resulting halves, then Cut again on the other half, then again, four cuts manually arranged. The tool does not plan multi-axis splits.
• No press-fit joinery. Alignment dowels are alignment-only — they keep the parts oriented during glue-up, but the connection isn't strong enough on its own. There's no option for dovetail, tenon/mortise, finger/box joints, puzzle, T-slot, or magnet-pocket joinery.
• No interlocking cut surface. The cut is always a flat plane. There's no option for a wave, zigzag, sawtooth, brick, or 2D pyramid cut profile that interlocks laterally.
• No automatic build-plate sizing. Orca doesn't know your build volume when planning the cut — you have to manually compute where each half lands relative to your printer's max X/Y/Z and confirm both halves fit.
• No print-farm distribution. If you have multiple printers, you have to allocate pieces manually.

How to split an STL with multi-axis cuts for OrcaSlicer

When you need more than one cut, or you want real press-fit joinery, the workflow becomes: cut the STL outside OrcaSlicer first, then load the resulting pieces into Orca for slicing.

1. Open splicestl in a browser tab. No install, no signup, no upload to a server.
2. Drop your STL or 3MF onto the upload area. It renders immediately in the 3D viewport.
3. Pick your printer from the preset dropdown, or set max X/Y/Z dimensions manually. The tool computes how many cuts each axis needs and shows them as translucent planes you can drag.
4. Choose joinery. 9 modes: square pegs (default press-fit), dovetails (slide-together), tenon/mortise (single big joint), finger/box joints, puzzle joints (lateral lock), T-slot, magnet pockets (for N52 disc magnets), dowel holes (for separate wooden or printed dowels), or none (clean cuts only). Each has tunable diameter, length, and tolerance for your filament's shrinkage.
5. Pick a cut surface profile. Flat is default and most compatible. Wave, zigzag, sawtooth, or brick give interlocking surfaces that resist shear — useful when the cut is going to be visible.
6. Download the zip. One STL per piece, an HTML assembly diagram, and a README.
7. Open all pieces in OrcaSlicer via File → Open. Each piece arranges on the build plate as a separate object. Slice and print as a normal multi-part job — Orca handles build-plate arrangement and supports just like any other multi-object print.

Comparison: Orca Slicer Cut vs. splicestl

Tips for clean Orca Slicer results

Use splicestl's "Brick" cut for hidden seams

If you're cutting a visible model where the seam will be obvious, splicestl's brick cut shape produces a stepped square-wave parting line that breaks up the visible seam into a pattern. Once printed and glued, the seam is much less obvious than a clean plane cut. Orca's flat cut leaves a single hard line at the seam.

Set tolerance for your filament

PLA shrinks roughly 0.2–0.3%, PETG 0.4–0.5%, ABS up to 0.8%. The default 0.2 mm peg tolerance in splicestl is calibrated for PLA. If you're printing in PETG or ABS, bump tolerance to 0.3–0.4 mm. Run a test peg first — splicestl includes the peg dimensions in the README.

Print one piece at a time, or all at once

OrcaSlicer supports both. For a 4-piece split, you can pack all four onto the build plate (faster, more supports), or use OrcaSlicer's Print Mode → One at a Time to print sequentially with a clean head park between pieces. The latter is better for fragile detailed pieces where one piece's first layer would scrape another mid-print.

Verify each piece fits before printing

After loading the pieces into Orca, use the Auto Arrange tool (default shortcut A) and check that no piece extends past the build plate edges. splicestl already guarantees each piece is within the dimensions you specified, but if you changed printer settings between splitting and slicing, it's worth a glance.

The summary

OrcaSlicer's Cut tool is excellent for single-plane splits with alignment dowels — the same feature set as Bambu Studio's Cut, since they share a codebase. For models that need multiple cuts, real press-fit joinery, or interlocking cut surfaces, cut the STL outside Orca first using splicestl, then load the resulting pieces into OrcaSlicer for slicing. It's a 30-second pre-processing step that unlocks everything Orca's Cut can't do.