Anycubic i3 Mega PID calibration is a crucial step to keep the hot end temperature at desired level.
Without it, you would get a thermal runaway error, or your printed model would have artifacs from changing temperature while printing.
How does it work?
The hot end will be heated up to desired temperature, turned off and these actions will be repeated a few times until the PID values will be calculated.
You can see how an extruder PID calibration looks like in a temperature graph from OctoPrint.
Move the printing head to the bed.
You should do this, because you print on the bed, not in the air.
PID calibration using Pronterface
Pronterface is a program to control your 3D printer via USB.
If you do not use OctoPrint, we will use this solution.
After downloading the pronterface, extract the folder and run pronterface.exe
Connect your printer via USB to your computer.
Open a device manager to identify the COM port.
Select a COM port and baud rate in the Pronterface.
Click on Connect.
Wait for a connection verification.
Send a M106 S255 command to turn on the cooling fan at the maximal speed – 100% (255 in PWM value)
Start PID Calibration
The first step is to determine the targeted nozzle temperature.
In this case we are calibrating it for a PETG – 100% cooling fan, printing temperature 245°.
In this case we are using a command: M303 E0 S245 C8 which means:
M303 – Start PID calibration
E0 – Extruder 0 calibration
S245 – Target temperature 245°C
C8 – Cycles – 8 cycles of heating and cooling
After calibration you will see PID Autotune finished!
Save new PID values
Read the new values from Pronterface
Fill in the values in X positions and send command: M301 PXX.XX IXX.XX DXX.XX
Send M500 command to save new PID values
Check new values by sending a M503 command