When printing on my Ender 3 Max Neo (stock except for a PEI bed), the right side of the bed is always printing too close. I manually leveled the bed, and then I run the auto-leveling sequence. I also have it set to run auto-level before every print, and confirmed that it’s enabled using M420 S1 after the G29 in the opening gcode.

I also disabled it in one test with M420 S0 and confirmed that it is making a difference so it appears to be working, but the auto-level map seems to be incorrect every time. Any ideas?

  • pepsison52895OPEnglish
    2·
    6 months ago

    I did some research and was able to pull the mesh. I put it into a visualizer and found that the right side is definitely incorrect (as it matches with the “too low” behavior that I’m seeing. I tried to copy the image here, but Sync won’t let me, but here’s the values.

     0        1        2        3        4        5        6        7        8        9       10       11       12
 0 +0.03500 -0.02855 -0.09156 -0.15566 -0.22250 -0.29867 -0.38125 -0.45758 -0.51500 -0.54590 -0.55844 -0.56363 -0.57250
 1 +0.01869 -0.01856 -0.05355 -0.09305 -0.14383 -0.21602 -0.30324 -0.38746 -0.45064 -0.48415 -0.49888 -0.50610 -0.51707
 2 +0.00234 -0.00695 -0.01215 -0.02553 -0.05938 -0.12765 -0.22023 -0.31329 -0.38297 -0.41951 -0.43676 -0.44629 -0.45969
 3 -0.01393 +0.00144 +0.02248 +0.03217 +0.01352 -0.05072 -0.14723 -0.24723 -0.32193 -0.36066 -0.37977 -0.39103 -0.40621
 4 -0.03000 +0.00178 +0.04016 +0.06533 +0.05750 -0.00240 -0.09922 -0.20143 -0.27750 -0.31633 -0.33563 -0.34711 -0.36250
 5 -0.04428 -0.00747 +0.03596 +0.06615 +0.06324 +0.00837 -0.08337 -0.18082 -0.25285 -0.28864 -0.30564 -0.31512 -0.32836
 6 -0.05734 -0.02364 +0.01604 +0.04376 +0.04156 -0.00781 -0.09062 -0.17835 -0.24250 -0.27303 -0.28596 -0.29184 -0.30125
 7 -0.07236 -0.04528 -0.01310 +0.00888 +0.00535 -0.03877 -0.11166 -0.18823 -0.24340 -0.26810 -0.27650 -0.27838 -0.28352
 8 -0.09250 -0.07094 -0.04500 -0.02781 -0.03250 -0.07238 -0.13719 -0.20465 -0.25250 -0.27246 -0.27719 -0.27582 -0.27750
 9 -0.11980 -0.10205 -0.08041 -0.06654 -0.07207 -0.10913 -0.16849 -0.22982 -0.27275 -0.28955 -0.29183 -0.28831 -0.28770
10 -0.15219 -0.13878 -0.12196 -0.11197 -0.11906 -0.15424 -0.20929 -0.26559 -0.30453 -0.31884 -0.31920 -0.31399 -0.31156
11 -0.18660 -0.17777 -0.16597 -0.16010 -0.16902 -0.20270 -0.25387 -0.30559 -0.34092 -0.35300 -0.35165 -0.34493 -0.34090
12 -0.22000 -0.21563 -0.20875 -0.20688 -0.21750 -0.24949 -0.29656 -0.34348 -0.37500 -0.38473 -0.38156 -0.37324 -0.36750
    • rambos@lemm.eeEnglish
      2·
      6 months ago

      I see the mesh, but cant tell what is wrong with it. Is your mesh about the same every time after running ABL? If you check any point on the right side, do you think your bed and nozzle are at the same distance after every ABL run, but sensor reading is wrong on that side?

      Basically you have to identify is your sensor faulty, otherwise your bed or X gantry might be moving in Z over time. Faulty sensor can be fixed or replaced or just go to manual mesh leveling.

      I would try probing the same point multiple times in a row and see what difference you see in readings. You could also do a manual mesh and compare it with auto bed mesh.

      Move nozzle close to the bed, disable XY motors and move nozzle around while observing the gap. 0.1 mm variation can be seen by naked eye (alternative to paper method) and you have 0.6 mm according to your mesh.

      Use a metal ruler (or something flat) and a light to confirm how much and where is bed bent, again visual inspection.

      • pepsison52895OPEnglish
        1·
        6 months ago

        The mesh ends up being pretty similar every time, showing that the right side of the bed is lower than the left. The concern is that, when printing after auto leveling, the nozzle is far too close on the right side, causing first layer issues, but all is well on the left. It’s almost like the printer believes that the nozzle is further from the bed than it actually is, but only on one side.

        I found that the bolts holding the gantry to the base had come loose slightly, and tightened them. That seemed to help a bit, but the issue is still there. I was going to try leveling the x gantry, but I’m still trying to figure out how to do so.