Extruder Heater Tuning
Prerequisites
You must have your parking post locations dialed in such that you can automatically pick up the extruder with the heater you wish to calibrate.
If you are planning to use a silicone "sock" for your hotend, do the heater tuning with the sock installed because tuning without the sock will yield different tuning parameters that can throw errors during operation.
When to Calibrate an Extruder Heater
You should (re)calibrate the extruder heater * if you have just built an extruder tool * if you replaced the heater cartridge * if you replaced the temperature sensor
Steps
for Duet2 + Duex5 setup or Duet3 mainboard only
NOTE: 4/20/2020 The following method will work for all configurations of a Duet2 setup and for heaters connected to the Duet3 mainboard. However, the Duet 3HC and Duet Tool board (for Duet3) will not work without some extra steps. Look for special instructions below.
Open Jubilee’s web page and navigate to the GCode Console. Tell Jubilee to pickup the extruder tool with the heater you wish to calibrate. Ensure that your extruder’s heater and temperature sensor are plugged in and that the sensor is reading believable results. If the extruder is hot, wait for it to cool to an ambient temperature (20-30C).
Finally, turn the extruder fans on.
Then enter:
M303 Hx S250
Where x is the extruder’s corresponding heater index. If you did not change the config, the heater index follows the convention of 1 + extruder_index. Also note that extruders are numbered starting from 0.
This procedure takes about 5 minutes and ramps the extruder heater up to 250C and then back down to near-ambient temperature. When the procedure is done, the console will report back with a message describing the heater parameters and listing any warnings.
When the machine is done calibrating, enter (Note: M500 does not work currently (4/20/2020) with 6HC boards that are paired with the PI, you will need to manually enter this information into your config.g file)
M500
to save the tuning results to the config-override.g file on the SD card.
for a Duet 3HC Board or Duet Tool Board
4/20/2020 Special instructions for remote boards: Currently there is no software support in For Duet3 for remote boards like the 3HC and Tool Boards. To Tune a heater that will be attached to a remote board, follow these additional steps. 1. Create a temporary wire harness to connect the tool in question directly to the 6HC board (save this harness for the future) 2. Create a temporary heater entry that assigns the heater to the pins you used on the 6HC board 3. Follow the standard procedure by running M303 Hx S250 where Hx will be the new temporary heater number 4. Manually add the tune to your config.g file (Ex. M307 H4 A452 C235 D5.5 V24.0) 5. Replace the V parameter the board VIN voltage as reported by M122 B# (where # is the CAN address of the board) when the heater is operating. 6. Return the wiring to normal and comment out the the temporary heater (you will want this for any time you add or modify a heater in the future)
Warnings
- It’s possible that the wiring for a heater or sensor was accidentally connected to a different tool. The calibration will abort if the sensor reading does not rise when the heater is turned on.