How to Prepare Your CAD Files for a 3D Printing Quote

<p>File preparation is where most prototype projects go wrong. Here's how to get it right before you reach out to a service bureau.</p><h2>Export as STL or STEP</h2><p>Most bureaus prefer STL (for direct print jobs) or STEP/STP (for review and potential modifications). Check with your bureau — many now accept native formats like SolidWorks .SLDPRT or Fusion 360 .f3d.</p><h2>Check for Manifold Geometry</h2><p>Your solid must be "watertight" — no holes, non-manifold edges, or inverted normals. Use tools like Meshmixer, Netfabb, or your CAD software's built-in repair utilities.</p><h2>Set the Right Resolution</h2><p>For STL exports, use a chord tolerance of 0.01mm or better. Low-resolution STLs produce faceted surfaces that show up in the final part.</p><h2>Specify Units and Scale</h2><p>Always confirm units (mm vs inches) when exporting. A misread unit can result in a part that's 25x too large or too small.</p>

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