In the quest to fine tune our printers I found a very good guide on how to calibrate the PID control of the Hot-End and the Heated Bed.
If you find that your hot-end temperature fluctuates more than you’d like it to or that it over-shoots or stops short of the set temperature then this is for you.
- Allow your hot end to cool to room temperature
- In Pronterface or Repetier, send the command: M303 Snnn (where nnn = the temperature you’re extruding at, eg 230 for ABS would be M303 S230)
- Wait whilst the printer ramps up and down the hot-end temperature
- Input results into your Firmware
The results you get back will look something like this:
bias: 101 d: 101 min: 145.48 max: 154.02
Ku: 64.06 Tu: 29.67
Input the last 3 sets of numbers into your firmware here:
#define DEFAULT_Kp 38.04
#define DEFAULT_Ki 2.35
#define DEFAULT_Kd 147.63
You can also do the same for the heated bed by using M303 E-1 Snnn (where nnn is the temperature you normally run the bed at, eg M303 E-1 S60)