A LulzBot user used the following process found at lincomatic.com to fine tune his thermistor PID settings within Marlin to better maintain his hot end temperature. Our LulzBot 3D Printers are shipped calibrated and accurate, but if you change your thermistor or would like to experiment, here is the procedure:

  • Allow your hot end to cool to room temp.
  • In the terminal in Pronterface, send the following command: M303 S230 if extruding ABS at 230. Change the number in the command to reflect the temperature at which you normally extrude. The M303 SXXX command will tune the extruder. Use M303 E-1 SXXX to tune the bed.

The hot end will then heat up and finally cool, while logging the temperature. When completed, similar values will be displayed:

bias: 101 d: 101 min: 145.48 max: 154.02

Ku: 64.06 Tu: 29.67

Clasic PID

Kp: 38.04

Ki: 2.35

Kd: 147.63

Enter that information into your Start Gcode in Slic3r using the following format, with your values substituted appropriately:

M301 P38.04 I2.35 D147.63

or for the heated bed: M304 P38.04 I2.35 D147.63

Enter the following command to save the PID settings to EEPROM.


Reslice your model. Your temperature fluctuations should be lessened and more consistent.