Printer: Anet A8 Board version: Anet 1.7 Z Probe: L12A3-4-Z/BX Filament sensor: None Firmware: Marlin 2.0.7.2
Main features enabled: SDSupport Z Probe auto bed level BAUD Rate 250000 to optimize Octoprint RPI 3B+
Disabled features: Boot screen PRINTJOB TIMER AUTOSTART STRING CONFIG H AUTHOR SDcard print confirmation
Actual binary size: 126616 bytes (99%)
To setup Z Probe Offset
M851 Z0 ; set Z offset to 0
M500 ; Save to EEPROM
M503 ; report EEPROM, double check Z offset is zero
G28 ; Home all axes
M104 SXXX ; Set extruder temp, replace XXX with your current materials extrusion temp
M140 SXX ; Set bed temp, again replace XX with your current materials heat bed temp
after target temps are met:
G0 Z0 ; send nozzle to current zero position above bed, observe this position
M211 S0 ; Disable endstops, proceed with caution
place a sheet of paper on the bed
lower your Z axis 0.1 mm at a time until your nozzle lightly grips the paper
M114 ; Get current position, note first Z position reported here, should be negative, mine is Z-0.7
M851 Z-X.X ; Set Z offset, replace X.X with your results from M114
M500 ; Save to EEPROM
M503 ; Report EEPROM, double check M851 output
M211 S1 ; Turn endstops back on
M500 ; Save
M119 ; Report endstop states, double check they're back on, then proceed
G28 ; Home all axes
G29 ; Probe bed
M500 ; Save results to EEPROM
Changing fan duct (PID Auto Tune)
This step is very important, so don't blame the fan duct if you have not performed it and you are getting bad results :) Every time you install a new fan duct, it's highly recommended to perform the so-called "PID Auto Tune" procedure on your heat block. It's performed very easily - when your printer is cold, connect it to your PC, and start your preferred program that allows you to send GCODE commands directly to your printer. You can use Pronterface (http://www.pronterface.com/) or whatever you prefer (some slicers have this function built in). Next, decide what's your preferred print temperature - in my case it's 190C. You will also have to turn the fan ON. Execute the following GCODE command to turn it on:
M106 S255 Now run the PID auto tune GCODE command (replace "190" with whatever temperature you use):
M303 E0 S190 C8 It will respond with Info:PID Autotune start
Your printer will go through 8 cycles of heating / cooling, so it will take a couple of minutes. In the end, you will get a response, that looks something like this:
bias: 92 d: 92 min: 196.56 max: 203.75 Ku: 32.59 Tu: 54.92 Clasic PID Kp: 19.56 Ki: 0.71 Kd: 134.26 PID Autotune finished ! Place the Kp, Ki and Kd constants in the configuration.h
Copy this response somewhere, otherwise it will quickly get lost in the idle "wait" messages. Now go to save your settings with the command (replace values):
M301 P[Kp] I[Ki] D[Kd]
And save with:
M500
When you have tuned your heater properly, the temperature will fluctuate by just plus/minus 0.5 - 1C and will be very stable.