How to prepare 3D files for 3D printing

In 3D printing, the journey from concept to physical product starts with a well-prepared 3D file. Understanding the details of file preparation is critical to producing high-quality prints. We will cover everything from supported walls to tolerance levels virtually to ensure your projects move smoothly from digital to physical.

Design-rule terms to know

Every process has its own limits. These are the file-prep details that decide whether a feature prints cleanly:

1. Supported walls: Walls that are connected to the rest of the print on at least two sides

2. Unsupported Walls: Unsupported walls are connected to the rest of the print on less than two sides

3. Support & overhangs: The maximum angle a wall can be printed at without requiring support

4. Embossed & engraved details: Features on the model that are raised or recessed below the surface

5. Horizontal bridges: The span a technology can print without the need for support

6. Holes: The minimum diameter a technology can successfully print a hole

7. Connecting/movement parts: The recommended clearance between the moving or connecting parts

8. Escape holes: The minimum diameter of escape holes to allow for the removal of build material

9. Minimum features: The recommended minimum size of a feature to ensure it will not fail to print

10. Pin diameter: The minimum diameter a pin can be printed at

11. Tolerance: The expected tolerance (dimensional accuracy) of a specific technology

Process limits at a glance

Typical minimums for the three processes we run. Send your file and our preflight tool checks these automatically:

Design feature	FDM	SLA resin	SLS nylon
Min wall (supported)	0.8 mm	0.5 mm	0.7 mm
Min hole diameter	2 mm	0.5 mm	1.5 mm
Embossed / engraved detail	0.6 mm wide, 2 mm high	0.4 mm	1 mm
Max unsupported overhang	45°	supports needed	none needed
Clearance, moving parts	0.5 mm	0.4 mm	0.4 mm
Min feature size	2 mm	0.2 mm	0.8 mm
Typical tolerance	±0.3 mm	±0.2%	±0.3%