Why is my print so bad

[jonnyvermont]

I have been having this issue for a while. While I sometimes get a proper print, why does this happen??? this is a standard benchy. 4mm nozzle.

[RocketSled]

Extruder is slipping, or the extruder stepper motor/stepper drive circuit is failing. Problem gets worse towards the end of the print because everything is hotter, and heat causes the issue to happen to a greater degree.

Start by taking the extruder apart and cleaning out any build ups of plastic, make sure things can turn smoothly.

[JonRaymond]

To me it looks like you either have a partial nozzle clog or the thermal grease has dried out.

See this thread for similar results.

Thermal Grease: Small Cause -> Big Effect on printing results

Since most Bambu Lab printers are the same age, I can imagine that this problem could affect several people here in the forum. My printer has been producing imperfect prints from time to time lately. After 3 weeks of vacation I wanted to use it yesterday and this is what I got as a result: [IMG_0421 2] So I cleaned the nozzle according to the instructions and was in good spirits when the next print looked pretty decent at first glance. When the printer stopped extracting filament after a …

[jonnyvermont]

I replaced the hot end, and I still have the same results. I think this rules out the thermal grease. So I guess I have to figure out how to repair the extruder next. Thanks for the replies!