One of the common problems that 3D printer users face is under-extrusion, which means that not enough filament is coming out of the nozzle. This can result in poor print quality, gaps, and weak layers. One of the possible causes of under-extrusion is that the filament is not heated up to its melting point, which means that it cannot flow smoothly through the nozzle.

How can you tell if your filament is not hot enough? Here are some signs to look out for:

• The filament is curling or bending as it comes out of the nozzle, instead of forming a straight line.
• The filament is making a clicking or grinding noise as it is pushed through the extruder.
• The filament is brittle and breaks easily when you bend it.
• The print surface is rough and uneven, with blobs and strings.
• The print layers are not adhering well to each other, and the print is weak and fragile.

If you notice any of these signs, you may need to increase the temperature of your nozzle. You can do this by adjusting the settings on your 3D printer’s control panel, or by using a slicer software to set the temperature for each layer. The optimal temperature for your filament depends on the type and brand of filament you are using, as well as the ambient temperature and humidity. You can check the recommended temperature range on the filament spool or on the manufacturer’s website.

However, be careful not to overheat your filament, as this can also cause problems such as clogging, oozing, and burning. You can tell if your filament is too hot if:

• The filament is dripping or leaking from the nozzle when it is not printing.
• The filament is bubbling or smoking as it comes out of the nozzle.
• The filament is discolored or charred.
• The print surface is glossy and smooth, with no details or texture.
• The print layers are sagging or warping, and the print is deformed.

If you notice any of these signs, you may need to lower the temperature of your nozzle. You can do this by following the same steps as above, but in reverse.

You can also use a temperature tower test to calibrate your nozzle temperature for different filaments. A temperature tower is a 3D model that prints at different temperatures along its height, so you can compare the results and choose the best one. You can find many temperature tower models online, or create your own using a slicer software.