Auto Bed Leveling Issues

SO i finally got my BLTouch to work but im having an issue when printing... I probe the bed with G32 S2 doing a 10 by 10 grid, i do this once a day seeing how its saved to eeprom, in my print start code i do a G29 witch probes the 3 points then the print starts,, I can see the zed motors moving to compensate for the out of wack bed but one side of my print is still digging into the glass... Now if its automatic bed leveling and the motors are moving to compensate for the craziness of an out of wack bed how is it the print is digging in like that??? 


  • Also G29 reenables autoleveling it is not meant to be run for z height. Z homing is. g32 calibrates so homing computes the right Z by testing at a xy position and correcting for G32 tilt. Then with G29 you replace that with an average of 3 points completely neglecting the tilt, so that z can be good or bad or in between.

    The other thing you need to know is G32 assumes a completely planar bed. 10x10 points is complete overkill to compute a rotation. If your bad is not completely flat or warps under temperature you need G32 S2 + G33 (distortion correction). With distortion correction it will follow the bumps you have in addition to the tilt. This correction gets reduced over Z so it corrects only at the bottom to get no problems with bumpy bed surface. Watch out as G33 has it's own setting of area and test points. Here every point is a correction point, but most beds are not that bumpy, just curl a bit up at the sides. So 5x5 is normally all you need but 10x10 will also work.
Sign In or Register to comment.