FDM VISUAL TROUBLESHOOTING
This section provides a list of common problems that can occur with 3D prints, and suggestions on how to
fix them (assuming the 3D model is good). Please remember that consumer 3D printers are still relatively
“new” devices, and when a print fails, the printer will probably not even know it and the extruder keeps
pumping out the filament. It has happened to quite a few people in the 3D printing community that left a 3D
print unattended overnight to come back to a huge melted ball of filament on their build platform because
the print peeled off the build plate and melted onto the hotend!
With good practices, and making sure to check on your prints fairly regularly, you will have great results!
Now, let’s look at some examples of what can go wrong, and how to fix those issues. Most all of the exam-
ples below will cause a 3D print to fail. There might be some examples that could be “ok” to let go and not
cause you to cancel a print, and those will be called out specifically.
UNDER EXTRUSION / OVER EXTRUSION
(CONSISTENTLY PRESENT THROUGHOUT
Symptom: The extruded lines of filament are either
too thin, or too thick. (Figure 5-13)
• Your filament might be out of tolerance (larger
or smaller than 1.75 or 3mm).
• Your filament might need a hotter or
colder temperature in order to flow more
• You might have some settings in your slicer not properly assigned.
Tolerance: Change your slicer’s settings to the actual diameter of your filament (changing from
1.75mm to 1.65mm for example, if that is what you measured).
Extrusion Percentage: Instead of changing your filament diameter, you can also change your
extrusion percentage away from 100% down to 95% or up to 105% (as an example). With a lesser
extrusion percentage, the printer will extrude slightly less material, thus lessening your overall
flow of material.
Temperature: 3D printers might have some variations in temperature. What one 3D printer
thinks is 200ºC might actually be 215ºC on another 3D printer. Change your temperature down
by 5ºC if your filament is oozing out of your nozzle (over-extrusion), or make the temperature
hotter by 5ºC if your filament is not coming out consistently enough.
FIGURE 513: Extrusion issues shown by a wavy surface pattern.
67 Chapter 5: Tips for Success in FDM Printing and Visual Troubleshooting Guide
Getting Started with 3D Printing 68
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