Strange first layer

[mykepredko]

@printeruser

How to make the teeth of the extruder gears to make good contact with the filament to generate enouch force to push the molten plastic out through the nozzle?

Can you send a photo of your extruder?

Normally, I would say tighten the tension screw but we would have to see what kind of extruder you’re using.

[EddyMI3D]

@printeruser

I use the E3D Revo

You may check for the correct thermistor is set:

sensor_type: ATC Semitec 104NT-4-R025H42G 

[3dcoded]

@printeruser

I am not sure what you mean by having the extruder tightened.

Prusa has a guide on how to tension the extruder.

MK3S/S+

MK3

@printeruser

Actually, is it a good idea to change the extruder to Hemera, Roto or whatever?

The stock Prusa extruder is pretty good. I only switched because I wanted a toolhead board, filament cutter, etc. Changing the extruder likely won’t help much.

[printeruser]

I bought the printer before the Pandemic. Never had issue due to the Idler screw. If the problems mentioned here are caused by it, don’t know why all of a sudden it has such a big negative impact. Any idea?

[mykepredko]

The screw could have come loose or the extruder assembly has worn out (which leads to idler screw issues).

Have you looked at this video:

Prusa: Filament not Extruding- Troubleshooting