Recently we’ve had a print failure where the print head dropped down in the middle of a print, crashed into the part and broke both the hot ends on the volcano extruders.
Here are a few steps we took to diagnose the problem.
Warping
Inspect the part to see if it the corners are warped. If the part lifts off the bed, it gets caught in the hot end and may cause the hot end to shear off.
G-code Errors
Open the g-code file in the software and check to make sure there are no errors in it. If you know the exact layer at which the print failed, search for it (In Notepad) in the g-code and make sure the Z height is increasing as it moves on to the next layer.
Movement check:
Using the controls on the board, move the Z axis to make sure it follows the “Move” commands correctly.
Couplings:
Remove the cover and inspect the couplings to make sure there are intact. Also, make sure the set screws on the couplings are tightened.
Check the LED on the motor. When the motor is enabled, the green LED flashes slowly. When the green LED is solid, the motor is disabled. Errors are indicated by combinations of red and green flashes as shown below.
If the Z motor still malfunctions, you may need to replace the pigtails on the motor. Swap out the pigtail with one from X or Y motor to confirm the pigtail issue.
SD card error
SD card errors are usually ignored since they are not very common. However, corrupted SD cards can cause your print to do unusual movements and cause print failures. After eliminating G-code errors, try printing the file with a different SD card and see if that fixes the issue.