# Ugly 3D printing with high precision

I am a totally beginner at 3D printing and I have this question: I see many 3D printers (at amazon) with Z precision as low as 0.1mm! To me that's amazing but what does not amaze me is this: when I see the printed objects of those 3D printers you can easily with naked eye see the "vertical steps". How?

A precision of 0.1mm should be really almost impossible to see. If a person printed using 0.1mm precision how can I see the vertical steps?

I know there are some smoothin techniques to make the surface better but that shouldnt even be needed if the printer actually printed at 0.1mm in the first case.

The 0.1mm refers to the thickness of each layer. However, it does not say anything regarding:

• How precise the layers are in the XY plane

• How precisely each layer is aligned with the previous in the XY plane

• How consistent the extrusion is: are all the layers printed with a consistent line thickness

No matter how fine the layers (and these printers that you refer to can definitely print 0.1mm layers just fine); if they're not well-aligned with each other, or the filament extrudes inconsistently, you're going to see the layer lines. It takes a rigid printer, with low-play bearings, a well-calibrated extruder and filament with a consistent diameter to get smooth-looking prints (but you will always see some layering, especially if you look up close). Also, since filament is extruded in a round shape, the sides of the object are not perfectly flat, but consists of many small arcs, which makes it easier to see the layer lines.

• ...and the filament that is extruded on each later isn't perfectly merged with the previous layer. Each layer on an outer shell is slightly rounded making the layer lines more prominent. Mar 10, 2017 at 3:01
• so it's a useless selling mark saying "Oh, with our printer you will have up to 0.1mm thickness of precision" if the extruder is not good, the structure is not rigid... Cause I am really amazed the amount of printers that state a 0.1mm precision BUT when you see the finished product it has very visible layers like a stair. Could you please tell me if there is any techinal detail that I can look at the printer to know if it's precision is good since I cant rely on the precision of the thickness of each layer? Mar 10, 2017 at 3:24
• @Samul There's no way to tell really. The layer thickness figure is completely useless, because printers that promise 0.1mm can usually do thinner layers just as well. Best way is to get a test print from the printer you intend to buy. Mar 10, 2017 at 4:51
• @Samul Probably the best thing that you can do is look at reviews (and working equipment) on YouTube. Thomas Sanladerer seems to be impartial (and his videos are excellent). There are plenty of useful reviews and tutorials out there. In the end, quality usually costs money.
– Mick
Mar 10, 2017 at 6:49