Hi All, I just got this printer last week and am just taking the leap into 3d printing. I’m experiencing an issue where the left Z axis lowers during print and tries to go past the Z end stop, causing the belt to jump and the extruder to plunge into the bed. I’ve replaced the Z end stop, still crashes. “Home All” leveling works fine. I’ve gone through all bed leveling procedures. The provided prints (set of owls) works perfectly The issue only happens on prints that I have downloaded from thingiverse or created in thinkerCad I’m using CURA to slice The correct printer is selected in CURA I suspect it’s a Gcode file issue, but I can’t seem to figure out what setting is causing this. When I compare the Gcode from the owl prints to that of the failed print I don’t see anything different in the start sequence Here is a poor video of what is happening: Anycubic i3 Mega Z Axis issue - YouTube Thoughts? Anycubic believes it’s a Gcode issue…

How did you resolve this issue? Im having the same problem you have.

Had the same problem and not sure why but this worked but I modified the first segment of my gcode (just cut and pasted in Notepad) and now the printer no longer crashes into the bed. this is the code I used.

;Set Temperature
M190 S60 ;wait for bed temperature
M109 S200 ;wait for hotend temperature
G21 ;metric values millimeters
G90 ;absolute positioning
M82 ;set extruder to absolute mode
M107 ;start with the fan off
;Move to Home
G28 ;move extruder to min endstops
;Position Extruder Head
G90 ;absolute positioning
M82 ;set extruder to absolute mode
G1 Z15 ;move the platform down 15mm
G92 E0 ;zero the extruded length
G1 F200 E6 ;extrude 6mm of feed stock
G92 E0 ;zero the extruded length again
G1 F3600 ;set maximum feedrate
M117 Printing… ;set LCD message
G5 ;set Bezier cubic spline

hope this helps