3D Printing Tolerances: Comparing Technologies
3D printing tolerances vary significantly depending on the technology used. Understanding the limitations and strengths of each process is crucial to selecting the most suitable solution for your project.
- FDM (Fused Deposition Modeling): FDM printers, especially in an industrial setting, can achieve tolerances in the range of ±0.2 mm or ±0.15%, but the quality heavily depends on machine calibration, filament quality, and slicing configuration. Thermal shrinkage and warping are more common in complex geometries or high wall thicknesses.
- SLA/DLP (Stereolithography): Offers excellent precision on small parts, with typical tolerances around ±0.05 mm. It is less prone to deformations, but requires careful post-curing to maintain dimensional stability.
- SLS (Selective Laser Sintering): Ensures consistent tolerances, often around ±0.3 mm, and is suitable for functional and complex components. However, surface finish and porosity can affect dimensional stability, especially in critical environments.
- MJF (Multi Jet Fusion): Further improves accuracy (±0.2 mm on medium scale), with homogeneous surfaces and reduced shrinkage. It is one of the most stable technologies for medium-to-small-scale serial production.
3dbooster selects the most suitable technology based on dimensional, functional requirements, and material, ensuring precise control over every variable.
3D Printing Tolerances: Materials and Shrinkage Behavior
The choice of material directly affects 3D printing tolerances. Each polymer has a specific behavior during cooling:
- PLA: low shrinkage (<0.2%), good dimensional stability.
- ABS: subject to shrinkage up to 1%, requires heated build plates and enclosed chambers.
- PA12 (nylon for SLS/MJF): excellent balance between flexibility and tolerance, but subject to minor variations in humid environments.
- SLA Resins: minimal shrinkage, but UV exposure over time can alter dimensions if not properly post-processed.
To control deformations, software compensation, geometry optimization, controlled cooling, and anchoring techniques (brim, raft, etc.) are employed.
Design for Additive and Final Tolerances: Precision Engineering
Design for Additive Manufacturing (DfAM) is crucial to maintaining 3D printing tolerances within the required limits. Designing a part considering the printing technology, cooling directions, and part structure can reduce accumulated errors and avoid subsequent mechanical adjustments.
Best practices include:
- Avoiding sharp edges and abrupt transitions between walls of different thicknesses.
- Maintaining symmetry and uniformity to reduce internal stresses.
- Using functional tolerances, supported by real data and simulations.
- Providing adequate clearances for moving assemblies or press-fits.
- Validating geometries through GD&T software to ensure compliance.
Mature DfAM experience or early-stage collaboration is necessary to optimize files and ensure consistent mechanical performance and tolerances.
Tolerance Measurement and Control
Declared precision is not enough: accurate control with tools like these is necessary:
- High-resolution 3D scanners for quick and detailed verifications;
- CMM probes for production samples in series;
- CAD vs. physical part comparisons, to monitor every deviation.
This quality control process allows maintaining the error margin within predefined and validated limits for each production batch.
Conclusion
Managing 3D printing tolerances is the result of an integrated approach involving technology, material, design, and quality control. Each variable can influence the final precision, but thanks to advanced tools and consolidated expertise, 3dbooster is able to offer reliable, repeatable, and customized solutions.
If you are designing a component with strict dimensional requirements, contact us: we are available to evaluate the best solution with you.
Share this article if you found it useful, or subscribe to the 3dbooster newsletter to receive exclusive technical content and updates. Follow us on our social channels for in-depth insights and real case studies.