Anet A8 bad/inconsistant extrusion after changing nozzle

[HugoG 0]

I just changed my nozzle on my Anet A8 after it was fully used up. When I started printing with my new 0.4mm nozzle (same as before) my extrusion was VERY bad and inconsistant, even so bad I couldn't continue printing because it would pull the first layer off.

 

If I compare it to my extrusion before the nozzle switch, it is really bad, even though I tightened everything as before. I am quite sure it doesn't have to do with adhesion to the heated bed since I use tape with pva glue.

 

Any advice on how to remove this under extrusion so I can continue printing?

 

All the specs:

• 25mm/s first layer print speed
• 200C nozzle
• 60C bed
• PLA materia;
• 0.4mm nozzle size

 

Let me know if there is anything else you need to know.

[MrMaint 0]

After replacing the nozzle, did you recalibrate your z-axis zero setting to the print bed surface? The old tip was probably worn away and the new tip is therefore much longer. This could account for it's "tearing away at the first layer". After the first layer, it should have raised up a consistent amount from the height of the first layer that the second layer should print with the proper layer thickness.

 

The only other idea that I can think of is that maybe the new nozzle has a sharp leading edge inside where the filament feeds into it. Maybe this is causing the filament to catch and jam inside the hot end, thus restricting the flow of filament from being consistent. 

 

As I wrote the last comment, I thought of another possibility, though less likely. Maybe there is a gap between the end of the new tip and the heat break tube (that should be tight against it). This maybe is also causing inconsistent flow and maybe even introducing air bubbles into the filament stream. Did you tighten the heat break tube against the end of the nozzle after tightening the nozzle all the way into the heater block? Then reset the clearance to the bed again, as this will change the length of the hot end.