3D Printing (FDM) Troubleshooting: A Beginners Guide

What can you do if the printed objects do not look as satisfying as you would like them to, or if the printing process does not work at all? 3D printing is a skill that has to be mastered. In this blog post you'll find some tips for beginners on how to troubleshoot 3D printing.

A full 3d printing beginners workshop (video) and 3D printing books for more detailed information can be found here.

1) Poor Bed Adhesion


Description: The print or the first layer does not stick to the printing bed. This problem is relatively vital, as the entire printing process will not work if the first layer is missing. So you can stop the printing process after the first minutes.


Cause: The most common cause of this problem is that the printing bed is not leveled correctly, i.e. the nozzle is too far away from the printing bed. Other causes can be too high printing speeds or an incorrect temperature setting (usually too low) for the printing bed or filament.


Solution: Level the printing bed and reduce the distance between nozzle and printing bed to about 0.1 mm by using the adjustment wheels of the printing bed (simple method: only a piece of paper should fit between nozzle and printing bed). Also reduce the printing speed and increase or check the printing temperature. The slicing setting "Brim" in Cura can also help.


2) Under- or Overextrusion


Description: Too little or too much material flows out of the 3D printer nozzle. This can lead to material shortage or excess material on the part. You can recognize it by the fact that the structures are printed very thin or very thick.


Cause: A FDM 3D printer usually has no feedback function to tell the software if enough material comes out of the nozzle. If too little or too much material comes out, but the 3D printer does not receive feedback, under- or overextrusion occurs. In other words, too little or too much filament is processed. A typical cause is often a wrong value for the filament diameter in the slicing software.


Solution: This problem can usually be traced back to an incorrect value for the setting "filament diameter" in the slicing software. Check if the filament diameter is entered correctly, depending on the filament type (e.g. 1.75 mm or 3 mm).


3) Clogged Nozzle


Description: There is no or very little material coming out of the printer nozzle and/or the extruder makes strange noises (clacking), but all other functions work as expected.


Cause: Most likely the nozzle of the 3D printer is clogged.


Solution: There are several ways to solve the problem. First, remove the filament, heat the nozzle manually, and clean it. You can also simply replace the nozzle if it is very worn or totally clogged. A new nozzle can be purchased for just a few bucks.


4) Warping


Description: A corner or a surface of the object to be printed detaches from the printing bed and is deformed upwards.


Cause: This phenomenon is known as warping. Causes can be e.g. a too low printing bed temperature, a non-planar printing bed (too large distance between nozzle and printing bed at some points) or also object specific slicing settings.


Solution: Check the printing bed temperature. With PLA, e.g. between 50 and 60° Celsius. If you cannot solve the problem this way, also try to activate the "Brim" function in the Slicing settings.


5) Stringing


Description: Stringing, also known as oozing, causes the formation of web-like formations surrounding the printed object.


Cause: This is usually caused by residual material being pressed out of the printer nozzle while the print head moves towards the next printing spot.


Solution: There are two important settings in the Slicing Software (e.g. Cura) to solve this problem. One is the setting "Activate feed" in the menu "Material". Here you can increase the feeding distance and the feeding speed. The second is the setting "Activate Coasting" in the menu "Experimental". Check both functions alternately and compare the results.


6) Scratches on the Top or Bottom of the Print


Description: Scratches appear on the printed object


Cause: To reduce the number of filament feeds, the printing nozzle may move within areas that have already been printed. This function is called "Combing". The problem with this is, that the hot printing nozzle melts plastic of an already printed layer on more time or draws material inside the object and thus leave marks.


Solution: In Cura you can activate the function "z-jump on retraction" in the menu "Movements", deactivate the "Combing" mode or set it to the setting value "Within the filling".



Author: John | 3DTech


Don't lose heart if things don't work out the way you have expected. You'll learn something new with every 3D printed part! In any case: "practice makes perfect". If you want to learn more about 3D printing, I recommend to you our video tutorial for beginners or our bestseller book: "3D Printing 101 | The Ultimate Beginner's Guide".