SLS minimum wall thickness questions usually come after a part has already failed. On 3D Printing Stack Exchange, a customer had a Nylon 12 part printed by an online SLS service. It “looked great” but didn’t work as expected, and they wanted to try again with 0.5 mm walls. They also asked whether metal plating could make thin walls stronger.
What is the SLS minimum wall thickness?
Most published guidance puts reliable powder bed walls at around 0.5 to 0.7 mm or more, depending on process, material and orientation. Rapidobject’s SLS/MJF design guidelines give 0.7 mm as the minimum process-safe wall for PA2200 on SLS and for PA12 on MJF. Below that, it says SLS walls are either automatically thickened to 0.7 mm or may not print reliably.
Can MJF go thinner?
For short walls, yes. HP’s MJF handbook recommends a minimum of 0.3 mm for short walls in the XY plane and 0.5 mm for short walls in Z. Rapidobject adds that 0.4 to 0.7 mm walls can be printed in MJF but are much weaker, and can break or develop porosity and holes.
Does length matter?
Yes. HP says that for cantilevers less than 1 mm wide, length divided by width should be under 1. For high aspect ratios, it recommends thicker walls or adding ribs or fillets.
What did the thread answer?
The only answer covered FDM nozzle sizes, not SLS, which is a common gap. Customers often get general 3D printing advice, not process-specific advice. On plating, Formlabs’ SLS post-processing guide lists electroplating as an option for SLS parts. Whether it rescues a 0.5 mm wall should be tested on the actual part, not assumed.
What should a bureau tell the customer?
- Ask what failed: breakage, flex or leaks.
- State your own minimum wall per process and material on the quote.
- Suggest ribs, fillets or a thicker wall where load allows.
- Offer a test coupon before a full run if they insist on going below your minimum.
Related on the Solvi blog: MJF Tolerances: Clearance for Holes and Nut Pockets; MJF Warping: Why Large Flat Parts Warp; MJF Watertight Parts: Can PA12 Hold Water Under Pressure?.
Sources: 3D Printing Stack Exchange thin walls question; Rapidobject SLS/MJF design guidelines (German); HP MJF Design Handbook; Formlabs guide to SLS post-processing.