The possibilities of 3D printing are incredible. But, it has happened to everyone that something goes wrong when printing a seemingly simple model. Everyone has experience with failed prints. However, some mistakes are simply the result of inexperience or carelessness and can easily be avoided.
- Power outage
Imagine you've been printing a complicated model for 30 hours and suddenly the power light starts blinking and the machine shuts down. Disaster! It is completely understandable that you are completely desperate in these situations. There are steps you can take to avoid this scenario. To begin with, you can check if the power cable is connected correctly. It may sound trite, but it's a simple mistake that happens to everyone. In this practical manual you can find out how to prevent this problem.
https://ultimaker.com/en/resources/21479-how-to-plug-in-power-cord 
- Spaghetti print
The model looked good and the print went as it should. Then you watch in horror as the model separates from the base and the filament continues to come out. And before you know it, everything looks like a plate of noodles. The solution lies in better adhesion to the substrate. It depends on the material used and the characteristics of the model you are printing. In order to prevent the print from separating, you can apply a thin layer of glue or put adhesive paper on the substrate. You should also check that you are using the correct settings for materials in CURA. Here are some tips to help with basic setup https://ultimaker.com/en/resources/257-build-plate-adhesion
- Missing layers
Something is wrong here. The material does not come out as it should and some layers are missing. However, it is not a major malfunction. It's probably just a matter of the 3D printer settings. Correct extruding of the material can be solved by matching the settings in the software of the material you are printing with and matching the printer to work with the specific material. If that doesn't work, maybe the "feeder" is blocking the filament and not allowing it to move properly. There are tips that can help when it comes to filament extrusion
https://ultimaker.com/en/resources/21477-how-to-fix-under-extrusion 
- Drops of molten filament
Unsightly blobs of melted filament appear on your smooth, perfect print. Unless you are printing props for a horror movie this is not the model you wanted. To avoid such accidents, make sure the printer head fans are running at full speed and double-check the temperature settings.
- Twisting and bending
The bottom layers of your model do not adhere to the substrate properly? This happens when the plastic cools too quickly and the result is bending of the bottom edges of the model. Fine leveling of the substrate solves this problem. Also, adding a thin layer of glue or adhesive paper can prevent warping of the bottom layers of the print. Depending on the material you are using, you can also use the protective "door" from the Ultimaker press kit. Learn more here
https://ultimaker.com/en/resources/19537-warping .
- Ominous cobweb
Everything was going well until threads of material started to appear all over and around the print, creating a "cobweb" around the complicated parts of your model. Small drops of filament ooze from the nozzle as it travels from one part of the print to another, creating a messy web around the model. The solution? Retraction of material - the process during which the "feeder" retracts the material as the head travels from one part of the print to another. This simple solution will eliminate the appearance of unwanted threads and "cobwebs". You can find more about the settings at this link
https://ultimaker.com/en/resources/19504-stringing 
- Cracks
Cracks in the model are also known as delamination and can destroy the 3D print. However, there are ways to solve this problem. Keep the 3D printer door closed and don't use too much cooling. Also, check the settings in CURA or use the door from the Ultimaker press kit.
Tell us your biggest fears when it comes to 3d printing. We hope you weren't too intimidated by this list. Do you think we missed something? If so, send us your biggest 3d printing nightmare.
Tell us your biggest fears when it comes to 3d printing. We hope you weren't too intimidated by this list. Do you think we missed something? If so, send us your biggest 3d printing nightmare.