TMC stepper driver autotuning Klipper python extra.
This extra calculates good values for most registers of TMC stepper motor drivers given the datasheet information for the motor.
In particular, it enables StealthChop where possible, CoolStep where possible, and correctly switches to full step operation at very high velocities. Where multiple modes are possible, it should choose the lowest power consumption and quietest modes available, subject to the constraints of sensorless homing (which do not allow certain combinations).
- Support for TMC 2209, 2240, 5160 at least partially tested. 2208 and 2260 may work, but are completely untested.
- Sensorless homing known to work on 2240 and 5160, provided you home fast enough (homing_speed should be numerically greater than the rotation_distance for those axes using sensorless homing). This should also work on other drivers, but presently untested. As always, be very careful attempting sensorless homing for the first time.
Preparation:
git clone https://github.com/andrewmcgr/klipper_tmc_autotune.git
ln -sr klipper_tmc_autotune/autotune_tmc.py $HOME/klipper/klippy/extras/
ln -sr klipper_tmc_autotune/motor_constants.py $HOME/klipper/klippy/extras/
ln -sr klipper_tmc_autotune/motor_database.cfg $HOME/printer_data/config/
Add the following to your printer.cfg, which assumes you have a Voron 2.4. Remove any sections for steppers you don't have (e.g. if you have less than four Z motors), add more if required. Motor names are in the motor_database.cfg. If a motor is not listed, add it, taking careful note of the units. PRs for more motors gratefully accepted.
[include motor_database.cfg]
[autotune_tmc stepper_x]
motor: ldo-42sth48-2004mah
sg4_thrs: 80
# Sensorless homing threshold, tune if using sensorless
voltage: 24.0
# Motor supply voltage for this stepper driver
[autotune_tmc stepper_y]
motor: ldo-42sth48-2004mah
sg4_thrs: 10
# Sensorless homing threshold, tune if using sensorless
voltage: 24.0
# Motor supply voltage for this stepper driver
[autotune_tmc stepper_z]
motor: ldo-42sth48-2004ac
[autotune_tmc stepper_z1]
motor: ldo-42sth48-2004ac
[autotune_tmc stepper_z2]
motor: ldo-42sth48-2004ac
[autotune_tmc stepper_z3]
motor: ldo-42sth48-2004ac
[autotune_tmc extruder]
motor: ldo-36sth20-1004ahg
This is compatible with homing overrides for sensorless homing, but take care to tune sg4_thrs and/or sgt through the autotune section if using 2240 or 5160 drivers, rather than by attempting to use gcode (that will not error, but won't do anything either as the autotune will override it). It should also work with any other homing overrides. Also use sg4_thrs via autotune with 2209, the code will correctly apply the value to the 2209's sgthrs field.
For sensorless homing, use the sgt field as the homing threshold for 2240 and 5160, the sg4_thrs for 2209 or 2260. sg4_thrs is also the CoolStep current regulation threshold, and can be used to tune that on 2209, 2240 and 5160 (on 2209, the same value as is used for homing will work correctly for CoolStep). A default value of sg4_thrs = 80 is usually reasonably close for CoolStep.
Add a voltage_margin if you have 2240 or 5160 drivers and wish to enable the overvoltage snubber (BTT SB2240 users should use voltage_margin: 0.8 for the extruder)