Under-Extrusion Explained
Nerved by 3D printer under-extrusion and don't know how to get rid of it? Check out this guide, which gives 3 simple solutions.
What Is Under-Extrusion?
Under-extrusion occurs when too little filament is extruded during a print. This can result in gaps, missing layers, insufficiently small layers, and even little dots or holes in layers. Print quality and even print strength is compromised when under-extrusion occurs.
In the following, we take a look at three easy fixes to under-extrusion that should eliminate this annoying problem.
Tip #1: Increase Extrusion Multiplier
If your extruder isn’t pushing enough filament, the most obvious course of action is to increase the extrusion multiplier (or flow) setting in your slicer. By doing so, more filament flows, (hopefully) resulting in satisfactory extrusion.
Tweak this setting by 2.5% until you find the right spot. Note, however, that increasing this setting too much can cause jamming. As a rule of thumb, don’t increase this setting to over 1.15 (or 115%). Otherwise, other problems will pop up.
Tip #2: Increase Print Temperature
If the print temperature is too low, filament won’t be able to flow properly. Therefore, nozzle temperature is an extremely significant factor when trying to fix under-extrusion.
Increase your print temperature by 5-degree increments until you find the proper temperature for your machine and material. You can tweak this setting either by repeatedly printing a test and adjusting the temperature or by printing a single temperature tower, with which you can test several temperatures at once.
Tip #3: Correct Filament Diameter
This fix resolves a very common mistake: incorrect filament diameter input. If you tell your slicer that, say, your filament has a 1.75-mm diameter, when, in fact, it’s 3 mm wide, the extruder won’t push the filament at a satisfactory rate.
Use calipers to measure your filament and find its correct diameter. Sometimes, even a .1-mm inaccuracy can cause printing issues.
Extra Tips & Tricks (For No Extra Charge)
- Speed: If your print speed is too high, your printer may have difficulty extruding enough filament in a shorter amount of time. Try decreasing your print speed by 20 mm/s and observe the result.
- Nozzle: If you notice that under-extrusion in your prints isn’t uniform, a likely cause is jamming. Make sure that your nozzle is clean and free of clogs.
- Bowden Tube: If your printer is driven by a Bowden-extruder system, you should check the tube. This is a likely origin of under-extrusion, as filament can get caught.
Hopefully, one or all of these ideas help you fix under-extrusion in your prints. Happy printing!