klipper/klippy/extras/z_tilt.py

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# Mechanical bed tilt calibration with multiple Z steppers
#
# Copyright (C) 2018 Kevin O'Connor <kevin@koconnor.net>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import logging
import probe, mathutil
class ZTilt:
def __init__(self, config):
self.printer = config.get_printer()
z_positions = config.get('z_positions').split('\n')
try:
z_positions = [line.split(',', 1)
for line in z_positions if line.strip()]
self.z_positions = [(float(zp[0].strip()), float(zp[1].strip()))
for zp in z_positions]
except:
raise config.error("Unable to parse z_positions in %s" % (
config.get_name()))
self.probe_helper = probe.ProbePointsHelper(
config, self, default_points=self.z_positions)
self.z_steppers = []
# Register Z_TILT_ADJUST command
self.gcode = self.printer.lookup_object('gcode')
self.gcode.register_command(
'Z_TILT_ADJUST', self.cmd_Z_TILT_ADJUST,
desc=self.cmd_Z_TILT_ADJUST_help)
def printer_state(self, state):
if state == 'connect':
self.handle_connect()
def handle_connect(self):
kin = self.printer.lookup_object('toolhead').get_kinematics()
try:
z_steppers = kin.get_rails('Z')[0].get_steppers()
except:
logging.exception("z_tilt stepper lookup")
raise self.printer.config_error(
"z_tilt requires multiple Z steppers")
if len(z_steppers) != len(self.z_positions):
raise self.printer.config_error(
"z_tilt z_positions needs exactly %d items" % (len(z_steppers),))
self.z_steppers = z_steppers
cmd_Z_TILT_ADJUST_help = "Adjust the Z tilt"
def cmd_Z_TILT_ADJUST(self, params):
self.probe_helper.start_probe()
def get_position(self):
kin = self.printer.lookup_object('toolhead').get_kinematics()
return kin.get_position()
def finalize(self, z_offset, positions):
logging.info("Calculating bed tilt with: %s", positions)
params = { 'x_adjust': 0., 'y_adjust': 0., 'z_adjust': z_offset }
def adjusted_height(pos, params):
x, y, z = pos
return (z - x*params['x_adjust'] - y*params['y_adjust']
- params['z_adjust'])
def errorfunc(params):
total_error = 0.
for pos in positions:
total_error += adjusted_height(pos, params)**2
return total_error
new_params = mathutil.coordinate_descent(
params.keys(), params, errorfunc)
logging.info("Calculated bed tilt parameters: %s", new_params)
try:
self.adjust_steppers(new_params['x_adjust'], new_params['y_adjust'],
new_params['z_adjust'], z_offset)
except:
logging.exception("z_tilt adjust_steppers")
for s in self.z_steppers:
z.set_ignore_move(False)
raise
def adjust_steppers(self, x_adjust, y_adjust, z_adjust, z_offset):
toolhead = self.printer.lookup_object('toolhead')
curpos = toolhead.get_position()
speed = self.probe_helper.get_lift_speed()
# Find each stepper adjustment and disable all stepper movements
positions = []
for s, (x, y) in zip(self.z_steppers, self.z_positions):
s.set_ignore_move(True)
stepper_offset = -(x*x_adjust + y*y_adjust)
positions.append((stepper_offset, s))
# Report on movements
msg = "Making the following Z tilt adjustments:\n%s\nz_offset = %.6f" % (
"\n".join(["%s = %.6f" % (s.get_name(), so) for so, s in positions]),
z_adjust - z_offset)
logging.info(msg)
self.gcode.respond_info(msg)
# Move each z stepper (sorted from lowest to highest) until they match
positions.sort()
first_stepper_offset, first_stepper = positions[0]
z_low = curpos[2] - first_stepper_offset
for i in range(len(positions)-1):
stepper_offset, stepper = positions[i]
next_stepper_offset, next_stepper = positions[i+1]
stepper.set_ignore_move(False)
curpos[2] = z_low + next_stepper_offset
toolhead.move(curpos, speed)
toolhead.set_position(curpos)
# Z should now be level - do final cleanup
last_stepper_offset, last_stepper = positions[-1]
last_stepper.set_ignore_move(False)
curpos[2] -= z_adjust - z_offset
toolhead.set_position(curpos)
self.gcode.reset_last_position()
def load_config(config):
return ZTilt(config)