By Printara · Published 25 September 2026 · 10 min read · Written for Bambu Studio 2.8

How to Split an STL in Bambu Studio (Cut Tool, Connectors and Dovetails)

Published September 25, 2026About 12 min read

Written for Bambu Studio 2.8

A model that is taller or wider than your build plate has to be printed in pieces. On an A1, P1S or X1C the limit is 256 x 256 x 256 mm, and on an A1 mini it is 180 mm in every direction. Bambu Studio can cut the model for you with its built-in Cut tool, and it can add connectors so the pieces line up when you glue them. This guide walks through the whole job in Bambu Studio 2.8, the current release in September 2026: where to put the seam, which connector to pick, the one setting that decides whether the parts actually fit, and where a slicer cut stops being the right tool.

Short version. Select the model, press C, drag the cut plane to where you want the seam, click Add connectors and place two or more on the cut face, set the Size tolerance to about 0.2 to 0.3 mm, click Confirm connectors, then Perform cut. Print each part with its cut face on the plate and glue them.

A sculpted bust split at the neck, the head lifted off to show two round dowel sockets in the cut face — The goal: a clean flat seam in a place nobody looks at, with sockets that line the parts up. Illustration from the Printara Academy.

Before you cut: four checks that save a reprint

1. Make sure it really does not fit. Press S to open the Scale tool and read the size in millimetres. A model that is slightly too long may fit diagonally, and a small scale-down is cheaper than a seam.

2. Choose where the seam goes. Put the cut where a line already exists: a belt, a collar, the top of a base, a change of material. Avoid faces, fingers and thin parts, and cut where the cross-section is large, because every connector needs solid material around it. A seam across a big flat area is also the easiest to glue and to hide.

3. Think about how each part will print. The cut face is flat, so it is usually the best face to put on the plate: no supports under it and a clean first layer. That choice affects the connector type, as you will see below.

4. Check the mesh. A model with holes or inverted faces can produce broken parts. If Bambu Studio shows a warning triangle next to the object in the list, repair it first (right-click the object, Fix model, on Windows) or clean it in your modelling software.

Step by step: cutting a model in Bambu Studio

1. Select one object

Import the STL or 3MF and click it. The Cut tool works on exactly one object; with several selected, Bambu Studio tells you Please select single object.

2. Open the Cut tool

Press C, or click the Cut icon in the toolbar above the 3D view. A cut plane appears through the middle of the object, with a panel of settings next to it.

3. Place the cut plane

Leave Mode on Planar for a flat cut. Then position the plane:

Drag the plane's arrow up or down, or type an exact value in Height.
Use Rotation and Movement for an angled or offset cut.
Hold Shift and drag across the model to plot a cut plane: the plane follows your line and stands perpendicular to the current view. Turn the camera first so the line you draw is the seam you want.
Flip cut plane swaps the two sides, and Reset puts everything back.

If the plane passes through a model with several separate islands, right-click an island to assign it to the other side of the cut.

4. Add connectors

Click Add connectors. The view switches to the cut face, and the panel shows the connector settings:

Type: Plug, Dowel, Snap or Thread (compared in the next section).
Style: Prizm or Frustum. Only plugs use it; a frustum tapers, which helps it seat.
Shape: Triangle, Square, Hexagon or Circle. Snap and Thread are always circles. A non-round shape stops the parts from turning against each other.
Depth ratio and Size, each with its own tolerance field.
Middle of geometry places a connector at the centre of the cut face.
For snaps, Bulge and Gap set how far the catch sticks out and how much room it has.

Left click on the cut face adds a connector, right click removes one, and dragging moves it. Shift + click adds a connector to the selection, Alt + click removes it, and Ctrl + A selects all of them so you can change their size together. Use at least two connectors, spaced well apart, so the parts cannot rotate. Click Confirm connectors when you are done.

5. Decide what happens after the cut

The After cut section lists the two parts, A and B. For each one you can choose Keep orientation, Place on cut or Flip. Place on cut lays the part on its flat cut face, which is usually what you want for printing.

Cut to parts keeps both halves inside one object as two parts instead of making two objects. That is useful when you want different settings per half but still print them together; it is not available once connectors are added or in Dovetail mode.

6. Perform the cut, then print

Click Perform cut. If Bambu Studio asks whether to fix open edges caused by the cut, say yes. The parts now appear as separate objects in the list, and dowels, if you chose them, appear as extra small objects. Press A to arrange, spread large parts over several plates if needed, slice and print. Dry-fit everything before you reach for the glue.

Plug, dowel, snap or thread: which connector to use

Part A on top, part B below. Dashed lines are the holes the cut tool subtracts. The tolerance you set makes each hole slightly larger than its peg.

Type	What you get	Best for	Watch out for
Plug	A peg on one part, a matching hole in the other.	Quick joints, nothing extra to print.	The peg sticks out of one cut face, so that part cannot lie on its cut face. Put the plug on the part you print cut face up.
Dowel	Holes in both parts and a separate pin object.	The default for FDM. Both parts lie flat on their cut faces.	Print the pins lying down for strength across the seam, and print one or two spares.
Snap	A peg with a bulge that clicks into a hole with room to flex.	Parts you want to take apart again: cosplay, storage, display pieces.	PLA is brittle; PETG or a tougher filament survives more clicks. Tune Bulge and Gap with a test.
Thread	A threaded pin and a threaded hole, always round.	Big parts that should screw together without glue.	Fine threads print poorly at small sizes. Use a generous Size and print a test pair first.

For most prints, two or three dowels are the safe choice: both parts keep a flat face for the plate, and a tight pin is easy to sand.

Tolerance: the setting that decides whether parts fit

Next to Size and Depth ratio there is a tolerance value. It makes the hole larger than the peg by that amount, so the parts slide together. If the Size tolerance reads 0, the peg and the hole are exactly the same size, and a printed peg will not go into a printed hole without sanding.

PLA or PETG on a 0.4 mm nozzle: start at 0.2 to 0.3 mm on Size.
Resin: much tighter, around 0.1 mm, because resin prints are more accurate.
Depth: a small depth tolerance keeps the peg from bottoming out, so the seam closes fully.

Printers and filaments differ, so treat these as starting points. Find your number with a test coupon: cut a 30 mm cube with the same connectors, print both halves, and adjust by 0.05 mm until the fit feels right.

Tip. If holes that sit near the plate come out too small, the cause is often the first layer squishing outward. Bambu Studio has an Elephant foot compensation setting in the process settings; a small value keeps the cut face and its holes true.

Dovetail mode

Switch Mode to Dovetail and the cut gets a groove along it: a rib on one part slides into a matching slot on the other. The Groove settings are Depth and Width (each with a tolerance), Flap Angle from 30 to 120 degrees and Groove Angle from 0 to 15 degrees.

A dovetail aligns itself and resists being pulled apart across the seam, which makes it good for long flat joints: sign panels, terrain boards, the halves of a tall box. It needs a seam that is long and thick enough to hold the groove, and a steep flap angle can leave overhangs on the slot side, so check the sliced preview. In Bambu Studio each cut makes one groove, and Cut to parts is not available in this mode. If you need several dovetails along one seam, OrcaSlicer has a Multiple dovetails option.

Cutting into more than two parts

Each cut turns one object into two. For three or more parts, repeat the Cut tool on each piece that is still too big. Plan the cuts from the largest problem down: a 500 mm statue on a 256 mm printer usually needs one horizontal cut first, then a second cut on the half that still does not fit. Rename the parts as you go (Top, Torso, Base).

Do not confuse Cut with Split. Split, with its To objects and To parts options, separates shells that are already disconnected inside the file, for example a figure and a loose sword saved together. It never cuts through a solid.

A winged statue shown in five colours, one per printable part: two wings, the halo, the figure and the base — One model, planned as separate parts: wings, halo, figure and base. Each seam sits where a part naturally ends.

Troubleshooting

"Invalid connectors detected: connector is out of cut contour". A connector sits partly outside the cut face. Drag it inward or reduce its Size.
"Some connectors are overlapped". Two connectors touch. Space them out or remove one.
"No one part is selected to keep after cut". Both parts are unticked in After cut. Tick at least one.
A plug or hole breaks through the outer wall. The cut face is too thin where the connector sits. Move it towards the thick middle, reduce Size or Depth ratio, or switch to glue only for that seam.
Parts fit, but the seam shows a gap. A connector is bottoming out, or the first layer has an elephant foot. Add a little depth tolerance or elephant foot compensation.
A part still does not fit the plate. Cut it again.

Where a slicer cut stops

Bambu Studio's Cut tool is free, already installed and good enough for most square-cut jobs. It has limits worth knowing before you start a large project:

Flat planes only. A plane is fine through a column and wrong through a shoulder, a handle or a neck, where the natural seam curves.
One cut at a time, placed by you. There is no plan from the bed size; you work out how many cuts are needed and where.
No wall check behind a connector. The tool warns when a connector leaves the cut face, not when the wall around its hole is too thin to print well.
No numbering or assembly notes. With ten parts, labelling them is up to you.
The cut lives in the project. The parts exist in your 3MF project; save it, or export the parts, if you want to reuse them.

How the Printara STL Splitter does the same job

We built the Printara STL Splitter for the jobs where the slicer's plane is not enough. Splitting is free: you need a free Printara account to open a file, and no credits are used. On a desktop computer with 8 GB of memory or more, models up to 1.5 million triangles are cut in your browser tab and the file stays on your computer; on a phone, a smaller computer or for a larger model the cut runs on Printara servers, still for 0 credits, and the parts go to your library.

The Printara STL Splitter: a teddy model cut along a drawn loop, the halves pulled apart, two dowel pins in their sockets and a result panel with 0 percent cut error — A real split in the Printara STL Splitter: one drawn cut, two parts, two 6 x 6 mm dowels, 0 % cut error and a 1.5 mm wall proved behind every socket.

Draw the seam. Drag a stroke across the model and the cut follows your line, so a seam can run around a shoulder instead of straight through it. Straight cuts with two tilt angles and a millimetre offset are there too.
Let it plan the cuts. Pick your printer (the list includes the Bambu A1, P1S and X1C, the A1 mini and the H2D) and press work out the cuts; it finds the fewest planes that make every part fit.
Joints that are checked. Resin pins (the default), loose dowels, square keys, cone studs or sliding dovetails, with 0.2 mm clearance for FDM built in. Before a socket is placed, the splitter proves at least 1.5 mm of wall behind it, and a seam where no joint fits safely is reported as glue only.
Numbered parts and a guide. Joint numbers are engraved into both faces that meet, and the ZIP download holds one STL per part, the dowel STLs and a plain-text assembly guide.

Limits, so you know before you try: it takes STL only (not 3MF or OBJ yet), models up to 2,000,000 triangles, and it works best on a desktop; on a phone the cut runs on Printara servers. To print the result, import the part STLs into Bambu Studio, use Lay on face (F) to put each cut face on the plate, and arrange. There is also a four-minute Academy lesson on splitting a model.

Split your model in the browser

Free to use with a free Printara account. No credits, no watermark, no export limit.

Create a free account and split How the splitter works

FAQ

Where is the Cut tool in Bambu Studio?

Select one object and press C, or click the Cut icon in the toolbar above the 3D view in the Prepare tab.

Can Bambu Studio split a model automatically to fit the build plate?

No. You place every cut yourself, one plane at a time. A splitter that plans cuts from the bed size, such as the Printara STL Splitter, can work out the cuts for you.

What tolerance should I use for connectors in Bambu Studio?

For PLA or PETG on a 0.4 mm nozzle, start with a Size tolerance of 0.2 to 0.3 mm, print a small test pair, and adjust. With a tolerance of 0 the peg and the hole are the same size and will not go together without sanding.

Why is Cut to parts greyed out?

Cut to parts is not available once you have added connectors or when Mode is set to Dovetail. Remove the connectors or switch back to Planar to use it.

What is the difference between Cut and Split in Bambu Studio?

Cut slices through the geometry with a plane. Split, with its To objects and To parts options, only separates shells that are already disconnected inside the file. It never cuts a solid.