Under a long review of the Sinterit Lisa, one viewer asked the question many buyers have before spending money on desktop SLS: “Are those printed parts as strong as those from more industrial large expensive SLS printers?” The thread never got a numeric answer. The two machines’ published datasheets give one, with caveats worth knowing.
Is desktop SLS as strong as industrial SLS?
On paper, somewhat less. Sinterit’s PA12 Smooth datasheet for the Lisa X lists tensile strength of 38.44 MPa in X and 42.30 MPa in Y. EOS lists its PA 2200, printed with the Balance parameter set, at 48 MPa in X and Y. Desktop SLS parts are close, but not equal, in this one number.
Where is the gap bigger?
Elongation. Sinterit reports 4.55% elongation at break in X and 4.91% in Y. EOS reports 18% in X and Y for PA 2200 Balance. The Charpy unnotched impact numbers point the same way: 11.91 and 20.24 kJ/m² for the Lisa X, 53 kJ/m² for PA 2200 in X.
That matters more than tensile strength for clips, hinges and anything that gets dropped. A part that’s 80% as strong but stretches a quarter as far will crack where the industrial part bends. Both figures come from different manufacturers’ datasheets, so the test conditions may not match and the comparison is approximate.
Are these numbers directly comparable?
Not perfectly. They’re different PA12 powders, on different machines, with each vendor’s own specimens. Sinterit notes its tests used samples printed from fresh powder, and that final properties vary with design, orientation and material handling. The older EOS sheet says mechanical properties depend on x, y and z position and exposure parameters. Sinterit’s sheet lists only X and Y, so leave EOS’s Z values out of the comparison.
Refresh rate is the other cost to factor in. Sinterit lists a 22% refresh ratio for PA12 Smooth, which affects powder cost per build.
How should you decide?
If your part works mostly in tension and stiffness, desktop SLS can be enough. If it flexes or takes impacts, print the actual part on both kinds of machine and break them. A request for one sample from a bureau running industrial SLS costs far less than finding out in the field.
Related on the Solvi blog: Nylon 12 Tough vs Nylon 12: Is the Switch Worth It?; MJF vs SLS Parts: What Should a Bureau Tell Customers?; SLS Minimum Wall Thickness: How Thin Is Too Thin?.
Sources: YouTube: Sinterit Lisa SLS 3D Printer Review (3D Print – Tech Design), viewer question; Sinterit: PA12 Smooth technical data sheet for Lisa X; EOS: PA 2200 material data sheet; EOS: PA 2200 material data sheet (2009, via EPFL).