How to make spot adjustments after Manual Calibration

[CoreMatrix]

2 questions if ok.

1. For the manual Calibration i know you’re supposed to do it lower it until the plastic strip just about pinches and bends. But is this what you all do?

2. After the manual calibration if my z 1st layer has say 2 spots which are too high and 3 that are too low, how do you increase of decrease those areas.

At the moment I only know how to increase or decrease the z-Level for the entire bed.

[TK4132]

1. Yes, that’s pretty much how you calibrate the Z level.
2. You can lower or raise the z offset height for the whole pad on the fly, not for specific parts of it. You could manually calibrate the machine to get better results than the auto calibration, but other than that your only solution is to go to a glass or garolite plate.

[Mxbrnr]

1. Yes.
2. It CAN be done, but the process is not very straight forward. You will need to control the machine via your computer and Luban so that you can read the coordinates of the machine for the calibration points. You then use G-code commands to position the toolhead at the appropriate points and to change the value for the individual points.
   It goes something like this:

• M503 (displays bed mesh points under the G29 lines)

• Determine which I-J coordinate system point you want to adjust

  

• • The I-J coordinate system is pre-programmed points used only in the bed mesh measurements, and they do not directly correspond to the machines actual coordinates, except in the z-height (as seen above). Example: on a 3x3 mesh the center point will be I1 J1, but on a 5x5 mesh the same physical point will be I2 J2, and on an 11x11 it will be I5 J5 (Note that I = X-axis and J = Y-axis, and in all cases I0 J0 is the point at the front left of the machine, where the filament purge is done).

• G1029 W I2 J3 (positions the ABL probe over the bed mesh point I2 J3) Ref: https://snapmaker.github.io/Documentation/gcode/G1029-abl

• • If you are doing manual leveling, you will then have to manually move the toolhead so that the nozzle is over this point instead of the probe. The offset varies between single extruder and dual extruder. Screenshot taken directly from the latest firmware:
    
    

• M421 I2 J3 Q-0.05 (subtracts 0.05mm from the current z-height of the point) Ref: https://snapmaker.github.io/Documentation/gcode/M421

• • You can also manually position the head to the exact height you want, note the actual coordinate height, and then use M421 I2 J3 Z###.## to set the actual coordinate z-height for that point

• M500 (saves the changes)