3D Printing: How to Fix Cracks in Tall Prints

Sometimes, you can end up with horizontal cracks appearing where two layers have just split apart when printing objects. These cracks tend to be more common on taller prints. Which gives a hint as to what the cause of the problem might be. As with so many 3D printing issues, the temperature is the problem here, specifically its lack. While nothing can be done to fix existing prints, it is possible to adjust some settings to hopefully prevent the issue from affecting future prints.

Temperature is critical in 3D printing as the filaments react in certain ways when heated to specific temperatures. Many filaments need to be printed onto a heated print bed. This significantly aids the adhesion of the first layer, preventing either the edges from bowing or the entire thing from popping off the print bed entirely. The heat from the print bed conducts through the entire print, helping to keep it warm. This effect helps newly printed plastic to print to the previous layers. However, the effect also gets weaker higher up the print. This means that if you’re too close to the minimum temperature of the material you’re printing with, you’re more likely to end up with temperature-related issues such as cracks the higher you go.

Tips to Troubleshoot the Appearance of Cracks in Taller Prints

The best thing you can do to address this issue is to increase the temperature of the print head. Generally, a good starting point is to increase the temperature by 10 degrees. This raises the plastic temperature as it is printed and results in it staying hot for longer. The longer the printed plastic stays hot, the longer it has to properly bond with the previous layer. Just be sure to check the filament manufacturer’s instructions for the printing temperature ranges and not exceed the maximum temperature.

Another thing you can do to help keep the printed plastic hot as long as possible is to reduce the speed of the print cooling fans. This will reduce the airflow the cools the print, essentially having the same effect as heating the filament more without running the risk of overheating it. Make sure not to lower the fan speed too much, however, as the printed plastic does actually need cooling.

Adjusting the print bed temperature won’t help much unless you’re seeing the issue starting really low in your prints. When increasing the print bed temperature, keep an eye out for the bottom of your print bowing, indicating that the first layers are too hot.

These tips should help you to be able to address the appearance of cracks in your taller prints. If you’ve got any other tips to help deal with cracks in taller prints, feel free to share them down below.