When my Ender 3 prints a top or bottom layer, it leaves a line on the layer. enter image description here

enter image description here

  • Slicer Cura
  • Linear Advance: 0.57
  • Retraction: 3 mm @ 35 mm/s
  • Max Speed: 100 mm/s
  • Ironing enabled
  • Minimum wall flow: 20 %
  • Temperatures: 205 °C hotend and 65 °C bed

My belts are tight enough as I push them they spring back up. I bought a support block for my Z lead screw to help with z banding (I also removed it to see if it will fix the issue but it didn't). I tried 50 mm/s, No Infill, swapped out to brand new 0.6 mm nozzle (the picture has 0.4 mm), Minimum wall-flow to 0 % but no improvement. It has to lead me to think its a mechanical issue but I am not sure where to start.

  • $\begingroup$ Try calibrating again it E steps and, if it doesn't help, try reducing the extrusion multiplier by 1-2% $\endgroup$
    – FarO
    Apr 24, 2020 at 20:08
  • $\begingroup$ @FarO I have calibrated e steps and flow rate from E3Ds guide. I tried 95% and 98% extrusion but it made it more more prominent. My current extrusion multiplier is 99.3% $\endgroup$ Apr 25, 2020 at 6:34
  • $\begingroup$ However you see that the excessive extrusion happens only near the edges, where there is deceleration. Are you sure the linear advance calibration is correct? $\endgroup$
    – FarO
    Apr 25, 2020 at 7:27
  • $\begingroup$ In the calibration test, there is a bump but its the best compared to the others. I will do another test without LA and check the difference. $\endgroup$ Apr 26, 2020 at 19:40
  • $\begingroup$ There is no difference.just the corners are more bumpy $\endgroup$ Apr 30, 2020 at 21:17

1 Answer 1


I have found the issue. My extruder gear was deformed after 4 months of continuous use which made the extruder have a difficult time when a rapid change in extrusion happened. I swapped it out to a new stainless steel one and it has been working well so far.


These inconsistencies are mainly caused by the pressure in the nozzle not changing fast enough. So to solve this you should look at the extruder setup as that is where the pressure is being controlled. Get any gunk out of there and make sure the path is clear and make sure nothing is grinding and you have a good grip on the filament.

To reduce the change in pressure you should play with printing speed, hotend temperature, linear advance if applicable and you may tune extruder jerk and acceleration although not necessary.

  • $\begingroup$ Thank you! I did the same thing (I was already using aluminum extruder and switched to BMG) and it improved slightly. I found another person having similar issues and I think he was pointing to the same thing - sudden changes in extrusion totally caused it: reddit.com/r/3Dprinting/comments/ag1xq5/… $\endgroup$ Feb 17, 2021 at 20:22
  • $\begingroup$ My next step will be switching to direct feed. Will update once I have it :) $\endgroup$ Feb 17, 2021 at 20:22

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