Learning Through Educational Tools: Layer Height

When setting up a print in a slicer, layer height can be key for several different instances. I touch on it in the overhangs post. You will hear layer height referred to as microns or micrometers, in either case, it refers to a millionth of a meter. When I got into 3D printing, micron increments of 300, 200, and 100 were the standard. Now, the terminology has moved toward just using micrometers (µm), or millimeters. For instance, 0.3, 0.2, and 0.3 millimeters. Or 300, 200, 100 µm.

For reference, a sheet of paper is close to 100 µm thick. A human hair is somewhere between 17 to 181 µm. So, the layer height of a printed object can be thinner than a human hair. For Fused Filament Fabrication (FFF), some users have gotten them to print at 50 µm, or even 25 µm with enough fiddling. Though, those layer heights are very challenging to print properly. Since speed and temperature, become major issues, and clogs become a strong possibility.

Sometimes referred to as fast mode, 0.3mm is one of the thicker layer heights. It is often used when speed is preferred over detail. Compared to 6 hours at 100 µm, it would only take around 3 hours . This setting can also be useful for extra strength, since the thicker layers are more likely to melt together, and form stronger bonds. Particularly when combined with the proper infill and infill percentage.

This layer height has issues with overhangs, or steep angles. If you are going to have any steep overhangs or want detail, then it may be best to use one of the thinner layer heights.

The median value for layer height is often close to 0.2mm, since it balances strength, speed, and quality. It is a good middle ground for most prints. It can print most overhangs quite well, with minimal drooping. It also offers decent detail for most larger prints. It prints faster than 100 µm, around 4 hours, instead of 6. That is largely why it is one of the most common layer heights used.

When you want detail, 100 µm and below are the best options. I have used this layer height for several detailed models. Like game pieces, character models, and detailed terrain. The layers are so close together that you can barely see, or feel them. That said, they can be a little weaker, and take a long time to print. The 6 tiles I printed of the item below took close to 24 hours to print. Even so, they came out beautiful! So, it is up to you as to what layer height works best for you.

Keep in mind that the whole time the printer is printing, it is using energy to heat the hotend and print bed. It also causes more wear and tear on the machine. So, keep that in mind when choosing layer heights. Decide accordingly as to whether you want speed or detail. Plan ahead for print time, double the print time for 100 µm prints, just to be safe. Usually I add an hour or two to the estimate of 200-300 µm prints.

Think ahead, and plan for failed first layers. Different layer heights can affect the adhesion of the first layer, particularly for manually leveled print beds. A print bed calibrated for a 300 µm layer height can be too far from the nozzle, and one set up for a 100 µm layer height can be too close. If you take anything away from this; remember that planning, and careful thought can help you (and your prints) succeed!