If your 3D prints are coming out spongy, the most likely cause is under-extrusion. Under-extrusion is when the printer does not supply enough filament to the nozzle, resulting in gaps and holes in the printed object. Under-extrusion can be caused by various factors, such as clogged nozzle, low extrusion temperature, incorrect filament diameter, or faulty extruder.
In this article, we will explain how to identify and fix under-extrusion problems in your 3D printer. We will also provide some tips and best practices to prevent under-extrusion from happening in the first place. By following these steps, you can improve the quality and strength of your 3D prints.
Under-extrusion can manifest in different ways, depending on the severity and the cause of the problem. Some common signs of under-extrusion are:
Spongy or porous surface
Incomplete or missing layers
Thin or weak walls
Gaps or holes in the infill
Poor adhesion between layers
Rough or uneven edges
Stringing or oozing
To identify under-extrusion, you can use a caliper to measure the dimensions of your printed object and compare them to the expected values. You can also inspect the surface and the cross-section of your print for any defects or inconsistencies. If you notice any of the signs mentioned above, you are likely dealing with under-extrusion.
How to fix under-extrusion
The first step to fix under-extrusion is to determine the cause of the problem. There are several possible causes of under-extrusion, and each one requires a different solution. Here are some of the most common causes and how to fix them:
Clogged nozzle: A clogged nozzle is when the filament gets stuck or blocked inside the nozzle, preventing the proper flow of material. This can happen due to dust, dirt, or burnt filament residue. To fix a clogged nozzle, you can try cleaning it with a needle, a wire brush, or a cold pull method. You can also try increasing the nozzle temperature or using a different filament material.
Low extrusion temperature: A low extrusion temperature is when the nozzle is not hot enough to melt the filament properly, resulting in poor extrusion and adhesion. This can happen due to incorrect temperature settings, faulty thermistor, or ambient temperature fluctuations. To fix a low extrusion temperature, you can try increasing the nozzle temperature or using a heated bed or an enclosure. You can also try calibrating the thermistor or replacing it if it is damaged.
Incorrect filament diameter: An incorrect filament diameter is when the filament does not match the specifications of the printer or the slicer, resulting in incorrect extrusion calculations and feed rates. This can happen due to poor quality filament, filament swelling or shrinking, or wrong slicer settings. To fix an incorrect filament diameter, you can try measuring the actual diameter of your filament with a caliper and adjusting the slicer settings accordingly. You can also try using a different filament brand or type.
Faulty extruder: A faulty extruder is when the extruder mechanism does not function properly, resulting in inconsistent or insufficient filament feed. This can happen due to worn out gears, loose belts, slipping hobbed bolt, or electrical issues. To fix a faulty extruder, you can try tightening the screws, belts, and springs, lubricating the gears and bearings, cleaning the hobbed bolt, or checking the wiring and connections. You can also try replacing the extruder or upgrading to a better one.
The best way to prevent under-extrusion is to maintain your 3D printer regularly and follow some best practices when printing. Here are some tips to prevent under-extrusion:
Use high-quality filament that matches your printer and nozzle specifications
Store your filament in a dry and cool place, away from moisture and sunlight
Clean your nozzle before and after each print, and replace it if it is worn out or damaged
Calibrate your extruder and your slicer settings to ensure accurate extrusion and feed rates
Use a cooling fan to improve the print quality and reduce stringing and oozing
Avoid printing too fast or too slow, and adjust the speed according to the layer height and complexity
Use a raft or a brim to improve the adhesion and stability of the first layer
Use a suitable infill pattern and density to provide enough support and strength to your print
Conclusion
Under-extrusion is a common problem that can affect the quality and strength of your 3D prints. It can be caused by various factors, such as clogged nozzle, low extrusion temperature, incorrect filament diameter, or faulty extruder. To fix under-extrusion, you need to identify the cause and apply the appropriate solution. To prevent under-extrusion, you need to maintain your 3D printer regularly and follow some best practices when printing. By doing so, you can improve your 3D printing experience and enjoy better results.
