1. Prep:

Set cooling fans (if applicable) to 100% to make sure you're  getting accurate calibrations) 

G-code command:

M106 S255;

2. Prepare for PID Autotune:

G-code command:

M104 S200 ; 

This will preheat to 200°C, for example, but  other temps can be used by changing the S value to something else like "S210"

Reason: PID tuning will adjust the heating behavior of your hotend to avoid temperature fluctuations.

Action: Once the nozzle reaches a stable temperature, prepare the printer for the PID tuning process.

3. Run the PID Autotune Command:

   1. Reason: Autotune will adjust the PID values based on the new nozzle's thermal properties.

   2. Action: Use the M303 G-code command to initiate PID autotuning.

   3. G-code command:

4. M303 E0 S200 C8

5. 
   

   1. Explanation:

      1. E0: Refers to the first extruder (if you have multiple extruders, modify this accordingly).

      2. S200: Target temperature (adjust this to your target filament temperature, e.g., S240 for ABS).

      3. C8: Number of cycles to perform (8 cycles is typical).

6. 
   

7. 4. Wait for the Autotune to Complete:

   1. Reason: The printer will heat the hotend to the target temperature several times to measure how it responds.

   2. Action: Wait until the process is completed (it may take a few minutes). The printer will return the tuned PID values (P, I, D).

8. 
   

9. 5. Save the New PID Values:

   1. Reason: After the autotune, you must save the new values so the printer uses them for future prints.

   2. Action: Use the following commands to set and save the new values:

      1. Set the PID values returned by the autotune:

10. M301 P[Your P value] I[Your I value] D[Your D value]

11. For example, if the returned values are P20.12, I1.10, and D75.25: 

12. M301 P20.12 I1.10 D75.25

13. Save the settings to EEPROM (so they persist after a reboot): 

14. M500  ; Save the settings

15. Verify the New PID Settings:

    1. Reason: It’s good practice to confirm that the new values have been applied.

    2. Action: Use the M503 command to print the current settings, verifying that the PID values are correct.

    3. G-code command:

16. M503

17. 7. Test the Printer:

    1. Reason: After tuning the PID, run a few test prints to ensure that the temperature is stable, especially during printing.

    2. Action: Start a test print and monitor the temperature graph (if using software like OctoPrint), or watch the temperature readout on the printer’s LCD to make sure it stays within a ±2°C range of your target temperature.