FDM vs. SLS 3d Printing

15mm (1:100 scale) Vickers Medium Mk.II
SLS on the left, FDM to the right.
The figure is a 15mm WW1 British officer by Peter Pig.
(Click on image to enlarge)

Here are two 3d printed versions of essentially the same digital model. On the left, one that I had printed by Shapeways using their SLS sintered nylon process, and on the right one that I printed myself in PLA on my FDM machine (Ender 3). Neither is fine-scale modelling quality, but both are adequate for wargaming models.

The detail on the SLS-printed model is very soft, and often entirely absent — many of the rivets are barely visible, if they can be seen at all. On the FDM-printed model, the detail is much crisper, but the layer lines are much more apparent. The surface texture from SLS is rather like very fine sponge, and it sucks up paint like sponge too. On the FDM model, flat horizontal planes are quite smooth, but the sloping panels are perceptibly ridged if you're looking closely.

The biggest differences, of course, are cost and delivery time. Getting a model this size printed in SLS by Shapeways costs quite a lot ($US20.00, plus postage — another $US15.00 to New Zealand) and usually takes a month to six weeks to get to me. The FDM model cost me maybe fifty cents, and took about eight hours in total to print.

It is possible, of course, to get better quality prints from Shapeways, but they are much, much more expensive than SLS printing.