I don't know if you've ever had a situation where you're printing something that is unevenly extruded, causing unevenness on the surface of the model, which affects the quality and aesthetics. By carefully observing the printing process, we can identify the problem of unstable extrusion. For example, if a printer prints a straight line 20mm long and finds that the extrusion filament looks rippled or seems to fluctuate in size, then we may be experiencing this problem. Why is this happening?
The wire is stuck or tangled together
First we need to check the printer's spool, you need to make sure that the spool is smoothly rotating, plastic wire can be easily pulled out of the roll. If the wire is messy, or the resistance to free rotation of the consumable roll is too high, this can affect the smooth extrusion of material from the nozzle. Causes extrusion instability. This is a relatively common cause.
If the wire is not jammed and can be easily pushed through the extruder, then the next thing to check is the nozzle itself. It is possible that some small pieces, or foreign objects, have gotten into the nozzle and are preventing proper extrusion. If this is a problem, the nozzle needs to be cleaned. Consult the manufacturer for some guidance on how to properly and effectively remove foreign objects from the nozzle.
Unreasonable extrusion width
If the wire turns smoothly and the extruder is not blocked, we can check the printer settings. Open the "Modellight" software to find the factory mode settings.
Different printheads have different extrusion diameters, make sure you choose the right nozzle. If the extrusion width is too small than the nozzle diameter, it may lead to extrusion problems. In general, the extrusion width should be between 100% and 150% of the nozzle diameter. If the extrusion width is much less than the nozzle diameter, the nozzle will not be able to extrude a consistent amount.
Layer height is too small
Again, we set the print layer height very small, e.g. 0.01mm, which will leave very little space for the plastic to be extruded from the nozzle. There is only 0.1mm clearance under the nozzle, which means that the plastic may be difficult to extrude.
Poor quality of consumables
Another factor related to extrusion instability that we haven't mentioned yet is the quality of the consumables we use. A poor quality wire may contain other additives that affect the stability of the extrusion. It is also possible that the diameter of the wire is unstable, which can also lead to extrusion instability. Finally, many plastics, over time, have a tendency to degrade. For example, PLA tends to moisture in the air, which leads to a decrease in print quality. That's why PLA supplies are packaged with desiccants to help remove moisture from the roll of supplies. If you think your consumables are the problem, try replacing them with a new, unpacked, high-quality roll of consumables and see if the problem might be solved.
Extruder mechanical failure
If we have checked all of the above and still have problems with extrusion instability, then we can check the extruder for mechanical failures. Many extruders, for example, use drive gears with sharp teeth and the gears bite into the wire. This makes it easier to pull the wire back and forth from the extruder. These extruders can usually adjust the pressure of the gears on the wire. If set too loosely, the drive gear will not bite the wire in deep enough, which can affect the extruder's ability to accurately control the position of the wire. Consult your printer provider to see if your printer, too, has a similar adjustment mechanism.