Nozzle rubs on previous layers

  • I'm having a frustrating problem with my recent built custom 3D printer
    so every single print I made, from the third layer, the nozzle is "rubbing" on the already placed filament. This results in a complete mess, melting the previous layers with the nozzle / new extrusions coming, getting malformed and out of precision forms, if I leave this happening, my Y-axis motor (bed) start to jump steps (by the force of nozzle friction to cold material). To stop that symptom, at the beginning of this, I have to raise the Z-axis by hand turning about 1/8 rotation of T8 fuse. By doing this, every rest of my printing runs peaceful, nicely, and beautiful.

    I'm using Marlin firmware, the most recent version, and Ultimaker Cura. My nozzle size is 0.5 and I'm using Ultimaker Cura's Fine Preset (0.1 mm height)

    My stepper motors axis are very well calibrated (X, Y, Z and Extruder). I tried:

    • lowering and raising the print bed to get spaced or shrunken first layers to see if something helps,

    • tried to change Z home offset on display,

    • tried the M206 command to change the print zone of the Z-axis,

    • tried to change the first layer height on Ultimaker Cura,

    but nothing seems to solve my problems.

    Due to my lack of experience, I don't know what I could try to solve this frustrating issue. I already check and rechecked my mechanical structure and everything was fine solid and very well balanced and square.

    Photo of failed print - side

    Photo of failed print - front

    From comment:

    • Printing speed are 40 mm/s,

    • Temps:

    • Hotend: 220 °C;

    • Hot Bed: 120 °C;

    • I have also tried 110 °C,

    • My Z-axis uses 800 steps per mm (1/32 micro stepping on DRV8825 at RAMPS).

    I'm thinking about over extrusion but I have fine tuned my stepper, checked and rechecked for it and seems normal

    @eduardogarcia234 which material are you using. your above mention profile is for ABS.

    Going by what you think is happening, the Z is skipping steps.... or your over extruding. Bump the stepper current. if that's not it, change back to 1/16 or try other drivers and see. if it's either then those rods aren't 8mm per rev.

    Just wondering if you have tried printing something without a curved edge? Just because I have had similar problems when printing shapes that have had a curved edge like you have shown in the picture.

    "most recent version" changes: since this question has been asked, Marlin released 1.8, 1.9. 2.0 and possibly more.

    As @Trish states, saying that it was the *most recent version* isn't particularly useful. Even looking at the date of your date and correlating that with the release dates of Marlin may not give an accurate estimation as to the version that you were using. Could you edit your question and state the actual version that you were using, if you can remember? Thanks.

  • I have made some learning on mechanical setup and discovered some issues on my printer, there are few:

    1. Bed warped, even with glass (thin thickness), making BAL confused with Z-movement over the bed.

    2. Overextrusion making layer oversized in terms of thickness.

    3. Some of missing mechanical fine adjustments.

    The main reason for this symptom was the overextrusion (that made my X and Y axis jump some steps when hotend collapses in the already-printed materials on their movements).

    I hope this helps some of those who have this similar problem!

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Content dated before 7/24/2021 11:53 AM