Background
When using the cool plate in the slicer with a standard 0.4 nozzle machine and you home the nozzle, it starts home at the mid of the plate and the cool plate is a glue-on film that is about 0.7mm thick, This is compensated in the G-Code to home Z -1.5 on the exposed steel in the back creating a pressure on the nozzle to flatten the plastic and then it starts cleaning on Z -1.1 with slightly less pressure on the nozzle.
Issue
We start by switching to the correct plate type in the slicer thinking this will do more than changing the temperatures.
If I now switch to another plate type like a textured plate or the engineering plate there is no extra layer of thickness on the plate. Meaning the plate does not have a glued-on film that is 0.7mm thick.
Now when the homing sequence starts it will crash the print head into the bed at the back pushing the nozzle Z -1.5 down and creating extremely high pressure, now moving the nozzle up to Z -1.1 and start scratching the plate destroying the surface and the nozzle in the process.
Workaround
Create a new machine for each plate type and alter the G-Code for the Nozzle cleaning sequence.
Now on the engineering plate and textured plate I use Z -0.5 and Z-0.1
Summary
So I have found out why this is happening.
If you set the type of Plate you use in the slicer it will not compensate the G-Code for the different height offset to the exposed steel surface and engineering plate side for example.
The barcode in the calibration sequence might do some alternating to the G-Code that I don’t know of but it’s not working for me.
Solution for future update
Create an IF statement that will read the type of plate you have selected and that will automatically set the correct nozzle cleaning offset.
As this example
{if plate_type=="Coolplate"}
G0 X128 Y261 Z-1.5 F20000 ; move to exposed steel surface and stop the nozzle
M104 S140 ; set temp down to heatbed acceptable
M106 S255 ; turn on fan (G28 has turn off fan)
M221 S; push soft endstop status
M221 Z0 ;turn off Z axis endstop
G0 Z0.5 F20000
G0 X125 Y259.5 Z-1.01
G0 X131 F211
G0 X124
G0 Z0.5 F20000
G0 X125 Y262.5
.
.
.
.
.
.
;====All other plate types====
{elsif}
G0 X128 Y261 Z-0.5 F20000 ; move to exposed steel surface and stop the nozzle
M104 S140 ; set temp down to heatbed acceptable
M106 S255 ; turn on fan (G28 has turn off fan)
M221 S; push soft endstop status
M221 Z0 ;turn off Z axis endstop
G0 Z0.5 F20000
G0 X125 Y259.5 Z-0.1
G0 X131 F211
G0 X124
G0 Z0.5 F20000
G0 X125 Y262.5
.
.
.
.
.
.
{endif}
Original nozzle cleaning G-Code
G0 X128 Y261 Z-1.5 F20000 ; move to exposed steel surface and stop the nozzle
M104 S140 ; set temp down to heatbed acceptable
M106 S255 ; turn on fan (G28 has turn off fan)
M221 S; push soft endstop status
M221 Z0 ;turn off Z axis endstop
G0 Z0.5 F20000
G0 X125 Y259.5 Z-1.01
G0 X131 F211
G0 X124
G0 Z0.5 F20000
G0 X125 Y262.5
G0 Z-1.01
G0 X131 F211
G0 X124
G0 Z0.5 F20000
G0 X125 Y260.0
G0 Z-1.01
G0 X131 F211
G0 X124
G0 Z0.5 F20000
G0 X125 Y262.0
G0 Z-1.01
G0 X131 F211
G0 X124
G0 Z0.5 F20000
G0 X125 Y260.5
G0 Z-1.01
G0 X131 F211
G0 X124
G0 Z0.5 F20000
G0 X125 Y261.5
G0 Z-1.01
G0 X131 F211
G0 X124
G0 Z0.5 F20000
G0 X125 Y261.0
G0 Z-1.01
G0 X131 F211
G0 X124
G0 X128
G2 I0.5 J0 F300
G2 I0.5 J0 F300
G2 I0.5 J0 F300
G2 I0.5 J0 F300
I do 3d printing for 4 year but I don t know bambu stuff jet no to much