Community guideTips & tricks / Design for vapor smoothing
Will vapor smoothing change my part’s dimensions?
A little, and AMT has measured how much.
Two AMT whitepapers report dimensional change after PostPro vapor smoothing:
| Study | Material and process | Measured change |
|---|---|---|
| Vapor smoothing voxeljet’s HSS PA12 (Feb 2024) | PA12, High Speed Sintering | 0.39 mm (0.4%) |
| Performance improvements of vapor smoothed SLS PA2200 parts (Jan 2024) | PA2200, SLS | maximum 0.4% |
So in both studies the change stayed at or below 0.4%.
What that means for your design
- Most features will not notice. For cosmetic and general-purpose parts, smoothing is not usually a design driver.
- Tight fits will. Press-fits, snap-fits, bearing seats and sealing faces are where a fraction of a millimeter matters. See Press-fits, snap-fits and assemblies after smoothing.
- Measure on your parts. The figures above are for specific materials, printers and test geometries. Your geometry, material and recipe will give their own numbers.
How to check
Measure the same features before and after smoothing, on the same instrument, on a handful of parts. If you are evaluating vapor smoothing, ask for the features that matter to you to be measured as part of a benchmark.