When 3D printing, the appearance of your print is important. While some internal flaws can be accepted if they don’t impact the structural integrity, external flaws are completely different. The top of a print is the most visible part, and so flaws there are the worst. One issue that you may come across is pits and holes on the top of prints, especially on flat surfaces, in effect known as pillowing.
Pillowing happens when the top of a print partially collapses into the gaps between the infill structure. Unfortunately, these problems are impossible to fix as they only really become apparent at the end of a print. Thankfully, it’s possible to make changes to prevent this from happening in future prints.
Pillowing is an issue that can affect all 3D printers. Still, it’s much more common an issue for printers using the narrower 1.5mm filament rather than 2.85mm filament. If you’re facing this type of issue, then simply changing to a larger filament size can resolve the issue.
Cooling and More
Cooling is significant in 3D printing. Printers will come with cooling fans mounted next to the print head, designed to cool the plastic as soon as it is printed to solidify. Make sure that your cooling fans are running and are correctly aimed to direct cool air over recently printed material.
Several popular 3D printers have popular community modifications, such as an improved spool holder. Cooling fan shrouds are also popular modifications. If they are running, make sure they’re running at their highest speed and potentially investigate upgrading your cooling with better fans and fan shrouds.
Another potential fix is to make the top layer thicker. By increasing the thickness of the top layer, you increase its structural integrity. Typically, you want to normally aim for around 6 layers and potentially up to 8 layers with smaller nozzles and filaments. However, the exact values depend on your layer height and how your slicing software sets this value. Some software may need you to specify the number of layers. In contrast, others may require you to just specify a thickness in millimeters.
Pillowing leaves an ugly effect of pits and holes on the top sides of 3D prints, most often on flat surfaces, where the top material sinks into the gaps in the infill material. Hopefully, these tips help you troubleshoot the cause and fix pillowing if your prints are suffering from it. If you have any other tips for dealing with pillowing, please share them down below.