Extrusion decreases speed after Klipper

General Discussion
1

Basic Information:

Printer Model: Ender 3 V2 Neo
MCU / Printerboard: 4.2.2 gd32f303
Host / SBC: Debian 13 Laptop
klippy.log

klippy.log (519.5 KB)

Describe your issue:

Hello there, so i recently managed to install klipper on my ender 3 after I have been struggling for some time ( I’m new to this ). I managed to calibrate everything, using printer.cfg files for the ender 3 v2 neo from the internet and then making some changes so it is tuned for my printer, but there is one last thing that is not working. For context, the ender 3 v2 neo comes with a bowden extruder, thanks to a modification I found online I was able to take the bowden setup and transform it into a direct drive setup, which on marlin, worked flawlessly. But on Klipper I am having some issues, when I try to extrude 15mm or more, the extrusion first works fine but then it slows down massively, and thus it doesnt extrude the demanded amount, the stepper motor continues to move at the same speed but the filament slips maybe because of the back pressure. I cleaned the old nozzle/ installed a brand new one, I used another filament, I set the temperature lower, I cleaned the inside of my extruder which wasn’t clogged, I changed my bowden tube ( the old one was still fine ), I changed the gear tension ( tighter and lighter, the way it was before it worked perfectly on marlin ), I tried setting more esteps, but nothing works. So I thought I might ask on this forum hoping someone could teach me some wise new things.

Thanks in advance

2

If gears slips on filament, and you are sure that there is no mechanical issues, its one of two.

  • Your nozzle temperature is to low
  • You are extruding to fast

For the first one, check the thermistor config, make sure you are using right one. Then run a PID tune.

For the second one, just check the speed you are extruding, calculate volumetric flowrate for example here, and compare to you hotend specs. For the standard ender 3 hotend, max flow rate is about 8 mm3/s

3

Which is about 4.5 seconds for the 15mm extrusion you mentioned. Try your 15mm @ 3mm/s.

4

I thank you very much kind people, my extrusion speed was set to 10mm/s, no wonder there was back pressure XD. I set it to the values you have provided me and it works perfectly now. What a dream