Tobold's Blog
Saturday, October 13, 2018
Printing miniatures in ABS

I am somewhat less enthusiastic about my choice for 3D printer since I found that the Zortrax M200 plus has an extruder with only a single roller, which explains my difficulties of printing with PLA. The roller just slips on the harder, smoother surface of the PLA filament and doesn't feed it correctly. As I can't do much about the extruder, I gave up on PLA, and am now exclusively printing in ABS.

For some applications, ABS is not a bad material. It is the stuff Lego stones are made off. Which means that if I achieve good layer-to-layer adhesion, I can print items that are rather tough. However for pieces which are rather thin, ABS is not the best material, as it is less stiff than PLA. Plus it gives of more harmful vapors when heating it, although I can much limit that with the HEPA filter I bought. The tiles I print for my dungeons come out good in ABS, and are nearly indestructible. Printing miniatures for my D&D game, heroes and monsters, is often far more problematic. Of course that depends on what sort of detail the miniature has, but things like legs, arms, and weapons are inherently not very thick at 1:60 scale (28 mm scale).

Part of the problem I overcome by printing thicker supports. In PLA I used to make support structures of 1 to 2 mm diameter, now I use 3 mm. But I still had sometimes difficulties with miniatures not coming out right. In some cases I could identify the problem as being support structures or lower parts of the model moving while printing. The print head is moving while deposing the next layer of material, and if the support isn't stiff enough, it can move and ruin the print.

I printed a while with ABS or toughened ABS (called ULTRAT) from the printer manufacturer, Zortrax. The results are okay, but the material is on the expensive side, especially the ULTRAT. So I started to experiment with materials from other brands. The cheapest stuff, e.g. Primavalue, didn't give very good results. I had more luck with Fillamentum Extrafill ABS. And it turns out that while the Zortrax printer limits the parameters you can set with Zortrax material, once you set the printer to "External" material, some parameters become available that are helpful for miniature printing.

So now I am using the "print speed" parameter to print my miniatures at half speed. The disadvantage is obviously that it takes twice as long. But it avoids the problems of the print head moving around finer parts of the print. And some of the details also come out a bit better. I even managed to print some miniatures with thin legs and wings correctly. So I now have solutions for everything I want to print. I still wished I could install a better extruder on my Zortrax M200 Plus, but for now I am okay.


I have no idea if it would work or not and am not quite brave, smart or rich enough to try it if it could potentially fail or ruin something, but Flexion has an old guide on how to replace the extruder on a Wanhao Duplicator (essentially a Zortrax M200 clone):

The reason I've been reluctant to test it is that this moves the X/Y point where the print nozzle would normally sit, which probably won't play nice with the closed source Zortrax firmware. On the other hand, the Z change would probably not be a problem at all since it uses electrical sensors on the build plate instead of just limit switches
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