HOW TO SPLIT A LARGE MODEL FOR PRINTING

Build plates are finite. A model 300 mm tall doesn't fit on a 256 mm Bambu - splitting into two pieces and printing separately is the answer. The pieces can be joined with adhesive (super glue, plastic cement), mechanical interlocks (dowel pegs, dovetails), or both. Done well, the joint is nearly as strong as a single print. Modern slicers (PrusaSlicer, OrcaSlicer, Bambu Studio) have built-in cut tools that split models cleanly along a plane and can auto-add alignment dowels. Cura needs a third-party tool or external mesh editor like Meshmixer or Blender.

Split when: the model is larger than your build volume in any single dimension; orientation is constrained (only one orientation works for the design but it doesn't fit); or supports would be excessive at a given orientation but split pieces could each print supportless. Don't split when: the model fits with rotation - try auto-orient first; or the part is load-bearing and the joint would be a structural weak point. For functional parts, larger printer or design-the-part-smaller is better than splitting.

PrusaSlicer / OrcaSlicer / Bambu Studio (built-in Cut tool): 1. Load the model. 2. Right-click - Cut. A cut plane appears around the model. 3. Position the cut plane by dragging the gizmo or entering an exact Z height. Place the cut where the joint will be least visible (a flat face, a panel line in the design). 4. Enable connectors (alignment dowels). Modern slicers offer 'connector' or 'dowel' options: - PrusaSlicer: Add Connectors - place 2-4 connectors per cut surface. Type: dovetail or peg. Size: 5-10 mm. - OrcaSlicer / Bambu Studio: similar interface - add several alignment connectors. 5. Click Apply Cut. The model splits into two separate parts. 6. Each part can now be oriented separately for optimal printing. Meshmixer (free, more control): 1. Import STL. 2. Edit - Plane Cut. 3. Position cut plane. Choose 'Slice (Keep Both)' to retain both pieces. 4. Export each piece as separate STL. Blender (advanced, for irregular cuts): 1. Import STL. 2. Use Boolean modifier with a plane or another mesh as the cutter. 3. Apply Boolean as Difference for one piece, Intersect for the other piece. Joining the printed pieces: - Super glue (cyanoacrylate): for PLA, PETG, ABS. Strong instant bond. Use Loctite gel or similar. - Plastic cement (e.g., Tamiya extra thin): chemically welds plastic. Works on ABS / ASA only (PLA isn't soluble enough). - Two-part epoxy: strongest joint, fills gaps. 5-minute or 30-minute cure. - Acetone slurry (ABS only): dissolved ABS scraps in acetone, painted on the joint, fuses chemically. - Mechanical (dowel pegs alone): holds for non-load-bearing parts but eventually loosens; combine with adhesive for permanent joints.

Cutting through visible features. A cut across the front face of a display piece is always visible. Plan the cut on a back face, hidden corner, or panel line. Skipping alignment connectors. Without dowel pegs, joining two halves squarely is hard - small misalignment compounds visually. Connectors too close to the edge. Edge connectors break off when fitting halves together. Keep connectors at least 5 mm from the cut perimeter. Glueing the wrong adhesive for the material. Plastic cement doesn't work on PLA. Super glue is fine for most. ABS can use acetone slurry. Not pre-fitting before glue. Always test-fit the dry parts to confirm alignment before applying adhesive.

After splitting, orient each piece for best print quality - see how-to-orient-model. For broken models that won't cut cleanly, see how-to-repair-stl. For choosing infill on the joining surfaces, see how-to-choose-infill (consider higher infill near the joint for stronger glueing).