How to Prepare Your CAD File

The fastest path from design to finished parts is a clean, correctly formatted CAD file. A good file eliminates quoting delays, prevents manufacturing holds, and ensures your parts arrive exactly as designed. This guide tells you exactly what formats we accept, how to export from the three most common CAD platforms, and the rules your file must follow.

Accepted File Formats

We accept files from any CAD system as long as they are exported in a supported format. Below is the complete format matrix by service:

DXF for Laser Cutting & Sheet Metal

DXF (Drawing Exchange Format) is the standard for 2D laser cutting. Your DXF should represent the flat pattern of your part — exactly the shape the laser will cut from the sheet.

DXF rules

• Scale 1:1 — Your file must be drawn at actual size. We will not scale based on written dimensions.
• Units: Inches or millimeters only. No centimeters.
• Single layer — All cut geometry on one layer. Remove dimensions, notes, borders, and title blocks.
• Closed contours only — Every shape must be a fully closed polyline. Open paths will not cut.
• No duplicate lines — Overlapping or stacked lines cause double cuts and part damage.
• No shared edges — Adjacent parts must not share a cut line. Leave at least 0.060″ gap.
• Convert text to outlines — Active text will not cut. Explode or convert to curves/paths.
• No construction geometry — Remove centerlines, center marks, and reference geometry.

STEP for CNC Machining

STEP (Standard for the Exchange of Product Data) is an ISO-standard 3D format that preserves exact solid geometry across all CAD and CAM systems. It is our preferred format for CNC machined parts.

STEP file rules

• Final geometry only — Your model should represent the finished part. Do not include machining stock, toolpaths, or fixture geometry.
• Confirm units — Note inches vs. millimeters in your order. STEP files do not always carry reliable unit metadata.
• No threaded features — Model threaded holes as plain (unthreaded) holes. Call out thread specs on the accompanying drawing.
• Include corner radii — Model all internal pocket radii. Do not leave sharp internal corners for the machinist to interpret.
• Single solid body — Multi-body parts should be submitted as an assembly or separate files.

STL for 3D Printing

STL (Stereolithography) files describe 3D geometry as a mesh of triangles. This is the standard input for FDM, SLA, and SLS 3D printing workflows.

STL file rules

• Watertight mesh — The mesh must be fully closed with no holes, gaps, or non-manifold edges.
• Minimum resolution — Export at medium-to-high resolution (chord tolerance ≤ 0.01mm). Low-resolution meshes produce visibly faceted surfaces.
• Correct orientation — Orient the part with the most critical surface facing up for best surface finish.
• Minimum wall thickness: 1.0mm for FDM, 0.5mm for SLA/SLS.
• No internal voids — Unless intentionally designed, ensure the model has no hidden internal geometry.
• Units: Millimeters preferred. If exporting in inches, note it in your order.

Exporting from SolidWorks

DXF (for laser/sheet metal)

1. Open your Sheet Metal part
2. Click the Flat Pattern feature in the FeatureManager to unfold
3. File → Save As → change type to .DXF
4. In the DXF/DWG Output dialog, select Flat pattern geometry
5. Uncheck bend lines and notes unless you want them on a separate layer
6. Click Save

STEP (for CNC machining)

1. File → Save As → change type to .STEP (AP214)
2. Under Options, select AP214 (preferred) or AP203
3. Click Save

STL (for 3D printing)

1. File → Save As → change type to .STL
2. Click Options → set Resolution to Fine
3. Set deviation to ≤ 0.01mm and angle to ≤ 5°
4. Click Save

Exporting from Autodesk Inventor

DXF (for laser/sheet metal)

1. Open your Sheet Metal part
2. Right-click the Flat Pattern in the browser → Create Flat Pattern
3. File → Save Copy As → select .DXF
4. In the dialog, uncheck sketch geometry and bend annotations
5. Click Save

STEP (for CNC machining)

1. File → Save Copy As → select .STP
2. Ensure the folded (3D) model is active, not the flat pattern
3. Click Save

STL (for 3D printing)

1. File → Save Copy As → select .STL
2. Set resolution to High
3. Click Save

Exporting from Onshape

DXF (for laser/sheet metal)

1. Open your Sheet Metal part
2. Right-click the part in the feature list → Export
3. Select format: DXF/DWG
4. Under “What to export,” select Flat pattern
5. Set units to inches or mm → click Export

STEP (for CNC machining)

1. Right-click the part → Export
2. Select format: STEP
3. Choose AP214 → click Export

STL (for 3D printing)

1. Right-click the part → Export
2. Select format: STL
3. Set resolution: Fine → click Export

Pre-Flight Checklist

Before submitting your file, run through this checklist to avoid delays:

All files

• ✓ File is in an accepted format (.DXF, .STEP, .STL, .SLDPRT, .IPT, .3MF)
• ✓ File is at 1:1 scale
• ✓ Units are confirmed (inches or mm) in order notes
• ✓ No dimensions, notes, borders, or title blocks in the cut file
• ✓ Material, thickness, and quantity specified in your order

DXF files (laser cutting)

• ✓ All contours are closed (no open paths)
• ✓ No overlapping or duplicate lines
• ✓ Text converted to outlines/curves
• ✓ Construction geometry removed
• ✓ Parts do not share edges — minimum 0.060″ gap
• ✓ Flat pattern exported (not folded 3D model)

STEP files (CNC machining)

• ✓ Final part geometry only (no stock, no fixtures)
• ✓ Threaded holes modeled as plain holes (threads on drawing)
• ✓ All corner radii present and dimensioned
• ✓ Accompanying 2D PDF drawing with tolerances and finish callouts

STL files (3D printing)

• ✓ Mesh is watertight (no holes or non-manifold edges)
• ✓ Exported at Fine resolution
• ✓ Wall thickness ≥ 1.0mm (FDM) or 0.5mm (SLA/SLS)
• ✓ Correct orientation noted if critical