Design guide

    File prep & export

    Most failed prints we see weren't bad designs, they were bad exports. Get the units right, get the mesh resolution right, and you'll never see a printability warning.

    The full pipeline

    Every CAD model goes through four stages before it's a printed part. The Export stage is where most things go wrong, wrong units, low mesh resolution, or unapplied transforms.

    Pick the right format

    FormatWhen to use
    STEP / STPAnything from real CAD (Fusion, SolidWorks, Onshape). Preserves true geometry, we can rescale or thicken walls if needed.
    3MFModern container with units baked in. Bambu-friendly. Use this from Blender 4.0+ or Fusion.
    STLUniversal fallback. Works from anywhere. Use Binary STL, never ASCII (smaller, faster).
    OBJFine for mesh modellers (Blender, ZBrush). Make sure normals point outward.
    PLYScanned parts. We'll repair holes if needed.

    Send STEP if your CAD tool will export it, it gives us the most flexibility.

    Don't send G-code

    Pre-sliced .gcode is locked to one slicer profile, one printer model, and one material, we can't change material or fix a printability issue. Always send the original mesh or STEP.

    Per-CAD export settings

    Fusion 360

    Recommended format: STEP (preferred) or STL

    1. Right-click the body → Save As Mesh.
    2. Format: STL (binary). Refinement: High.
    3. Units: Millimeters. Structure: One file per body.

    SolidWorks

    Recommended format: STEP AP242 or STL

    1. File → Save As → STEP (.step).
    2. For STL: Options → Resolution: Fine. Units: MMGS.
    3. Save assemblies as a single STEP, preserves the relative positions.

    Onshape

    Recommended format: STEP or STL

    1. Right-click part in the Parts list → Export.
    2. Format: STEP. Or STL with Resolution: Fine, Units: Millimeter.
    3. Export the whole Part Studio as one STEP if you want us to print everything together.

    Blender

    Recommended format: STL or 3MF

    1. Apply all modifiers and scale (Object → Apply → All Transforms).
    2. File → Export → STL (.stl). Tick Selection Only.
    3. Set Scale: 1.0 and verify the Unit Scale is 0.001 if you've been working in metres.

    Pre-export checklist

    • Units in millimetres. If your CAD is in inches, either convert before export or use the Scale dropdown on the upload card.
    • Apply all transforms / modifiers so the exported geometry is what you see on screen.
    • Mesh resolution: Fine / High. The default Medium is enough for prototypes but loses detail on curves.
    • One body per file unless you want us to print parts as an assembly. Multi-body STL is fine; multi-body STEP is preferred.
    • No internal voids unless they have a vent hole. Trapped air will cause the wall to bulge.
    • File size sanity check, under 200 MB. If your STL is 500 MB, the mesh is probably way over-resolved.

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    Last reviewed May 2026 · Rigid Prints engineering team