If your print bed or extruder oscillates 2-3°C around the target temperatures you should follow this guide to help your printer stabilize the temperature variance.
Tuning your PID settings on your printer are important. They're unique to your machine and should only need to be done once. PID tuning will help your printer maintain more consistent target temperatures for both the bed and the extruder.
Pictured below is an example of a printer's extruder oscillating around 200°C, which we do not want. The desired graph will have a flat line at the desired temperature.
1. Connect your printer to Wi-Fi and open the web dashboard on your browser.
2. Scroll down the main dashboard and look for the printer terminal. Click it to reveal the command line terminal.
3. To begin autotuning the extruder, type in or copy/paste M303 E0 C8 S200 in the type bar and hit SEND.
When tuning the heated bed, use command M303 E-1 C8 S85
4. Your printer will then heat to the target temperature (200°C) and fluctuate for a couple minutes. Once the process is complete, the terminal will read "PID Autotune Finished!" print values Default_Kp XX.XX / Default_Ki XX.XX
5. Click the 'autoscroll' button in order to scroll up to the new autotune variables. Type these values into the terminal in the format of M301 PXX.XX IXX.XX DXX.XX. Type the value after Kp after 'P' , Ki after 'I', and Kd after 'D'. Hit SEND. In this particular example, we entered M301 P25.26 I1.53 D105.44
When tuning the heated bed, type in M304 PXX.XX IXX.XX DXX.XX
6. Then type M500 into the terminal and hit SEND to save these values. You should now have a more stable temperature line when printing.
Whenever you reset EEPROM values you will need to rerun PID tuning on your printer.