One of the ugliest forms of bad 3D prints is overheating. Here’s some information on how to spot it, why it happens and how to fix it:
Signs of overheating:
Your print has the correct general shape but has deformed where it has overheated. This can be at the start of your print or part way through. See the tip of the (supposed) spike in the image that has become molten because of overheating.
Explanation:
Overheating is exactly what it says, the filament has become too hot and isn’t cooling enough. The main cause of overheating is insufficient cooling.
How to fix:
Increase the part cooling fans. If you’re not using 100% part cooling fans you can try increasing up to 100% which should help. This may not be suitable for all filaments though so be sure to check the manufacturers recommendations.
Try printing colder to begin with. Sometimes you can get away with a cooler printing temperature for the rest of the print with the same result. Alternatively, reduce the temperature when the printer is approaching the problem area.
Print slower, giving the print more time to cool down. Consider the 15 second rule: the time for the nozzle coming back to the same point on your object should not be less than 15s.
If your slicer supports it, set a minimum time per layer to ensure proper cooling. This usually results in the slicer dynamically slowing down the print speed to ensure the minimum layer time, which, in this particular case, won’t help all that much.
Pro tip: you could add a pause to the layer change script and park the nozzle away from the object for a few seconds.
Workaround: try printing two copies of the object at the same time, the travel moves between the 2 objects will increase the layer time and allow for more cooling.
Filament specific tips:
PLA is often printed with 100% cooling fans anyway so if you’re seeing overheating, it suggests your printing temperature is too high. We always suggest starting at the lower end of the suggested temperature range and work your way up.
ASA does not like fans or draughts. Part cooling fans should not reach more than 10-20% with ASA. A warm ambient temperature is best but that doesn’t mean print at the hottest temperature within the range. Try reducing your printing temperature if you experience over heating with ASA.
For other filaments that you’re already printing at 100% part cooling fans, try adding extra external fans next to the printer to provide further cooling.