An SLS lattice is often the first idea for a lightweight part. On 3D Printing Stack Exchange, a designer planned a 30 × 30 × 10 cm tricopter frame made from a tetrahedral honeycomb, with struts about 1 mm thick and 15 mm long, printed in nylon on SLS. They asked whether it was doable.
Can you print an SLS lattice like this?
Yes. Powder bed fusion handles lattices well because the surrounding powder supports the struts, but size, cost and depowdering decide whether it’s practical. One answer noted it had been done. Another said SLS was probably the best process for it, but that a part that size would be expensive. They suggested printed joints with wood or plastic dowels instead, which would be cheaper and easier to repair. A third answer recommended drain holes for any solid sections.
How much lattice can actually be depowdered?
A 2025 study in Polymers (MDPI) tested closed BCC lattices with 5 mm cells and vent openings, printed in PA12 on an HP MJF 4200. After sandblasting, X-ray images showed full powder removal through five cell layers at a relative density of 0.07 (1 mm struts). At 0.47 density (3 mm struts), only about 1.5 layers came clean. The authors conclude that the closed thickness of a lattice should be limited according to its density.
What do the design guides say?
- HP’s MJF handbook says lattices and thin, topology-optimized sections hold and re-radiate less heat, which improves dimensional accuracy. It notes that software such as Materialise Magics or nTopology can automate lattice design.
- Rapidobject’s guidelines say closed hollows print full of unfused powder. To remove it, they call for at least two opposing openings of at least 8 mm, with all internal surfaces mechanically reachable.
What should a bureau check before quoting?
- Whether the lattice is open or closed, and how deep it runs.
- Strut thickness against your own minimum feature size.
- How you’ll prove it’s clear: weighing, visual inspection, or X-ray for critical parts.
- Whether a simpler design, like the dowel-and-joint idea above, meets the need for less money.
Related on the Solvi blog: MJF Warping: Why Large Flat Parts Warp; Depowdering SLS and MJF Parts: When Is Automation Worth It?; MJF Packing Density: How Full Should You Pack a Build?.
Sources: 3D Printing Stack Exchange tetrahedral honeycomb question; Raz et al., Polymers 17(20):2804 (MDPI); HP MJF Design Handbook; Rapidobject SLS/MJF design guidelines (German).