z_tilt: Add support for Z_TILT_ADJUST

Add new module to support independent adjustments to multiple Z
steppers to account for bed tilt.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
This commit is contained in:
Kevin O'Connor 2018-05-21 14:48:01 -04:00
parent 4bf1b042b1
commit 3025638b9b
5 changed files with 152 additions and 2 deletions

View file

@ -169,6 +169,8 @@ class ProbePointsHelper:
self.results = []
self.busy = False
self.gcode = self.toolhead = None
def get_lift_speed(self):
return self.lift_speed
def start_probe(self):
# Begin probing
self.toolhead = self.printer.lookup_object('toolhead')

109
klippy/extras/z_tilt.py Normal file
View file

@ -0,0 +1,109 @@
# 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_stepper = kin.get_steppers('Z')[0]
z_steppers = [z_stepper] + z_stepper.extras
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.mcu_stepper.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.mcu_stepper.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.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.mcu_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.mcu_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)

View file

@ -23,6 +23,7 @@ class MCU_stepper:
self._min_stop_interval = 0.
self._reset_cmd_id = self._get_position_cmd = None
self._ffi_lib = self._stepqueue = None
self._stepcompress_push_const = self._stepcompress_push_delta = None
def get_mcu(self):
return self._mcu
def setup_dir_pin(self, pin_params):
@ -60,6 +61,7 @@ class MCU_stepper:
self._invert_dir, self._oid),
self._ffi_lib.stepcompress_free)
self._mcu.register_stepqueue(self._stepqueue)
self.set_ignore_move(False)
def get_oid(self):
return self._oid
def get_step_dist(self):
@ -75,6 +77,13 @@ class MCU_stepper:
if mcu_pos >= 0.:
return int(mcu_pos + 0.5)
return int(mcu_pos - 0.5)
def set_ignore_move(self, ignore_move):
if ignore_move:
self._stepcompress_push_const = (lambda *args: 0)
self._stepcompress_push_delta = (lambda *args: 0)
else:
self._stepcompress_push_const = self._ffi_lib.stepcompress_push_const
self._stepcompress_push_delta = self._ffi_lib.stepcompress_push_delta
def note_homing_start(self, homing_clock):
ret = self._ffi_lib.stepcompress_set_homing(
self._stepqueue, homing_clock)
@ -109,7 +118,7 @@ class MCU_stepper:
def step_const(self, print_time, start_pos, dist, start_v, accel):
inv_step_dist = self._inv_step_dist
step_offset = self._commanded_pos - start_pos * inv_step_dist
count = self._ffi_lib.stepcompress_push_const(
count = self._stepcompress_push_const(
self._stepqueue, print_time, step_offset, dist * inv_step_dist,
start_v * inv_step_dist, accel * inv_step_dist)
if count == STEPCOMPRESS_ERROR_RET:
@ -119,7 +128,7 @@ class MCU_stepper:
, height_base, startxy_d, arm_d, movez_r):
inv_step_dist = self._inv_step_dist
height = self._commanded_pos - height_base * inv_step_dist
count = self._ffi_lib.stepcompress_push_delta(
count = self._stepcompress_push_delta(
self._stepqueue, print_time, dist * inv_step_dist,
start_v * inv_step_dist, accel * inv_step_dist,
height, startxy_d * inv_step_dist, arm_d * inv_step_dist, movez_r)