Constant drift on delta printer

smoothie-forum
(modprobe_SW) #1

Hello,

Since I switch the electronic of a Spiderbot Delta printer (spiderbot dot eu) from megatronics v2 to smoothieboard I experience a strange issue on most of my prints.
I tried my best to isolate the issue, unsuccessfully. Any hint is welcome.

The issue: Constant drift toward axis X (alpha)

Most prints if not all tend to deviate against axis alpha, a small factor difficult to calculate, and varying when changing the config.
Therefore towers or walls with strait angle on the plane are not straight, angles in the same direction are between 80° and 85° instead of 90°

What I tried

First I tried printing a high tower like this thingiverse dot com/thing:229395 to measure the deviation. But this shape printed strait !
Then I worked on various STL files, most of them generated by openscad. As soon as the complexity raise, the issue appear. It seams related to arcs (see pictures).
Yet I’m doing all test with this file thingiverse dot com/thing:348121 which is useful :slight_smile: and quick to print.

When I check the head movements with a set square, the head is perfectly straight. For instance:

G28
G1 Z1 ; (I make a mark on the bed)
G1 Z200 ; (I place my set square and it's straight)
G1 Z1 X70 ; (mark)
G1 Z200 X70 ; (straight again)
and so on...

On the software side, I sliced with Cura and Kisslicer, both triggering the same issue.
My config (below) have been revisited many times, taking inspiration from the examples files (Kossel or Rockstock) of the wiki.

On the hardware side, the tree motors are the same and I even rotated the channel to ensure the issue is not coming from a malfunctioning motor (X->X, Y->Z, Z->X). The drifting appear always against X axis. Belts are tight with a measured weight on a leverage, bed is flat.

I have changed the following parameters in the config, sometimes observing a small improvement.

  1. delta_segments_per_second from 0 to 1000 (!), above 200 it seams to straighten a bit
  2. [alpha|beta|gamma]_steps_per_mm rounded to 89, it doesn’t change anything
  3. with config-override and without (I fixed gama_max in config and the bed is flat)
  4. from sd card and from usb
  5. from my computer and from octoprint on a raspberry pi
  6. with bleeding edge and stable firmware, recent and old

At that stage I lack of inspiration, does anyone have an bright idea to help following my Quest to the straight object ?


IMAGES TO COME EMBED (maybe, URL yet not allowed)
hadge tee tee pee colon slash slash www dot mirifique dot ch slash m slash [1-7].jpg

Regards,

/config

# NOTE Lines must not exceed 132 characters
# Robot module configurations : general handling of movement G-codes and slicing into moves
default_feed_rate                            4000             # Default rate ( mm/minute ) for G1/G2/G3 moves
default_seek_rate                            4000             # Default rate ( mm/minute ) for G0 moves
mm_per_arc_segment                           0.5              # Arcs are cut into segments ( lines ), this is the length for
                                                              # these segments.  Smaller values mean more resolution,
                                                              # higher values mean faster computation
#mm_per_line_segment                          5                # Lines can be cut into segments ( not usefull with cartesian
                                                              # coordinates robots ).

delta_segments_per_second 100 # for deltas only same as in Marlin/Delta, set to 0 to disable
# and use mm_per_line_segment

Arm solution configuration : Cartesian robot. Translates mm positions into stepper positions

arm_solution linear_delta # selects the delta arm solution
alpha_steps_per_mm 88.89 # Steps per mm for alpha stepper
beta_steps_per_mm 88.89 # Steps per mm for beta stepper
gamma_steps_per_mm 88.89 # Steps per mm for gamma stepper

arm_length 256.05 # this is the length of an arm from hinge to hinge
arm_radius 145.05 # this is the horizontal distance from hinge to hinge
# when the effector is centered

Planner module configuration : Look-ahead and acceleration configuration

planner_queue_size 32 # DO NOT CHANGE THIS UNLESS YOU KNOW EXACTLY WHAT YOU ARE DOING
acceleration 3000 # Acceleration in mm/second/second.
acceleration_ticks_per_second 1000 # Number of times per second the speed is updated
junction_deviation 0.05 # Similar to the old “max_jerk”, in millimeters,
# see
# and
# Lower values mean being more careful, higher values means being
# faster and have more jerk
z_junction_deviation 0
#minimum_planner_speed 0.0 # sets the minimum planner speed in mm/sec

Stepper module configuration

microseconds_per_step_pulse 1 # Duration of step pulses to stepper drivers, in microseconds
base_stepping_frequency 100000 # Base frequency for stepping, higher gives smoother movement

Cartesian axis speed limits

x_axis_max_speed 12000 # mm/min
y_axis_max_speed 12000 # mm/min
z_axis_max_speed 12000 # mm/min

Stepper module pins ( ports, and pin numbers, appending “!” to the number will invert a pin )

alpha_step_pin 2.0 # Pin for alpha stepper step signal
alpha_dir_pin 0.5 # Pin for alpha stepper direction
alpha_en_pin 0.4 # Pin for alpha enable pin
alpha_current 1.7 # X stepper motor current
alpha_max_rate 9000.0 # mm/min

beta_step_pin 2.1 # Pin for beta stepper step signal
beta_dir_pin 0.11 # Pin for beta stepper direction
beta_en_pin 0.10 # Pin for beta enable
beta_current 1.7 # Y stepper motor current
beta_max_rate 9000.0 # mm/min

gamma_step_pin 2.2 # Pin for gamma stepper step signal
gamma_dir_pin 0.20 # Pin for gamma stepper direction
gamma_en_pin 0.19 # Pin for gamma enable
gamma_current 1.7 # Z stepper motor current
gamma_max_rate 9000.0 # mm/min

Serial communications configuration ( baud rate default to 9600 if undefined )

uart0.baud_rate 115200 # Baud rate for the default hardware serial port
second_usb_serial_enable false # This enables a second usb serial port (to have both pronterface
# and a terminal connected)
#leds_disable true # disable using leds after config loaded
#play_led_disable true # disable the play led
pause_button_enable false # Pause button enable
#pause_button_pin 2.12 # pause button pin. default is P2.12
#kill_button_enable false # set to true to enable a kill button
#kill_button_pin 2.12 # kill button pin. default is same as pause button 2.12
# (2.11 is another good choice)
#msd_disable false # disable the MSD (USB SDCARD) when set to true (needs special binary)
#dfu_enable false # for linux developers, set to true to enable DFU

EXTRUDER 1

Extruder module configuration

extruder.hotend.enable true # Whether to activate the extruder module at all. All configuration
extruder.hotend.steps_per_mm 400 # Steps per mm for extruder stepper
extruder.hotend.default_feed_rate 1200 # Default rate ( mm/minute ) for moves where only the Extruder
extruder.hotend.acceleration 600 # Acceleration for the stepper motor, as of 0.6, arbitrary ratio
extruder.hotend.max_speed 50 # mm/
extruder.hotend.step_pin 2.3 # Pin for extruder step signal
extruder.hotend.dir_pin 0.22! # Pin for extruder dir signal
extruder.hotend.en_pin 0.21 # Pin for extruder enable signal

extruder offset

extruder.hotend.x_offset 0 # x offset from origin in mm
extruder.hotend.y_offset 0 # y offset from origin in mm
extruder.hotend.z_offset 0 # z offset from origin in mm

firmware retract settings when using G10/G11, these are the defaults if not defined, must be defined for each extruder

if not using the defaults

#extruder.hotend.retract_length 3 # retract length in mm
#extruder.hotend.retract_feedrate 45 # retract feedrate in mm/sec
#extruder.hotend.retract_recover_length 0 # additional length for recover
#extruder.hotend.retract_recover_feedrate 8 # recover feedrate in mm/sec (should be less than retract feedrate)
#extruder.hotend.retract_zlift_length 0 # zlift on retract in mm, 0 disables
#extruder.hotend.retract_zlift_feedrate 6000 # zlift feedrate in mm/min (Note mm/min NOT mm/sec)

delta_current 1.5 # First extruder stepper motor current

EXTRUDER 2

Extruder module configuration

extruder.hotend2.enable true # Whether to activate the extruder module at all. All configuration
extruder.hotend2.steps_per_mm 400 # Steps per mm for extruder stepper
extruder.hotend2.default_feed_rate 1200 # Default rate ( mm/minute ) for moves where only the Extruder
extruder.hotend2.acceleration 600 # Acceleration for the stepper motor, as of 0.6, arbitrary ratio
extruder.hotend2.max_speed 50 # mm/
extruder.hotend2.step_pin 2.8 # Pin for extruder step signal
extruder.hotend2.dir_pin 2.13! # Pin for extruder dir signal
extruder.hotend2.en_pin 4.29 # Pin for extruder enable signal

extruder offset

extruder.hotend2.x_offset -11.5 # x offset from origin in mm
extruder.hotend2.y_offset 0 # y offset from origin in mm
extruder.hotend2.z_offset 0 # z offset from origin in mm

firmware retract settings when using G10/G11, these are the defaults if not defined, must be defined for each extruder

if not using the defaults

#extruder.hotend2.retract_length 3 # retract length in mm
#extruder.hotend2.retract_feedrate 45 # retract feedrate in mm/sec
#extruder.hotend2.retract_recover_length 0 # additional length for recover
#extruder.hotend2.retract_recover_feedrate 8 # recover feedrate in mm/sec (should be less than retract feedrate)
#extruder.hotend2.retract_zlift_length 0 # zlift on retract in mm, 0 disables
#extruder.hotend2.retract_zlift_feedrate 6000 # zlift feedrate in mm/min (Note mm/min NOT mm/sec)

epsilon_current 1.5 # First extruder stepper motor current

Laser module configuration

laser_module_enable false # Whether to activate the laser module at all. All configuration is
# ignored if false.
#laser_module_pin 2.5 # this pin will be PWMed to control the laser.

Only P2.0 - P2.5, P1.18, P1.20, P1.21, P1.23, P1.24, P1.26, P3.25, P3.26

                                                          # can be used since laser requires hardware PWM

#laser_module_max_power 0.8 # this is the maximum duty cycle that will be applied to the laser
#laser_module_tickle_power 0.0 # this duty cycle will be used for travel moves to keep the laser
# active without actually burning
#laser_module_pwm_period 20 # this sets the pwm frequency as the period in microseconds

HOTEND 1

Hotend temperature control configuration

temperature_control.hotend.enable true # Whether to activate this ( “hotend” ) module at all.
temperature_control.hotend.sensor max31855 #
temperature_control.hotend.chip_select_pin 0.27 #
temperature_control.hotend.spi_channel 0 # SPI channel 0 or 1
temperature_control.hotend.get_m_code 105 #
temperature_control.hotend.set_m_code 104 #
temperature_control.hotend.set_and_wait_m_code 109 #
temperature_control.hotend.designator T #
temperature_control.hotend.max_temp 360 # Set maximum temperature
temperature_control.hotend.min_temp 0 # Set minimum temperature - Will prevent heating below if set
temperature_control.hotend.p_factor 25.5 # permanently set the PID values after an auto pid
temperature_control.hotend.i_factor 1.299
temperature_control.hotend.d_factor 125
#temperature_control.hotend.max_pwm 64 # max pwm, 64 is a good value if driving a 12v resistor with 24v.
temperature_control.hotend.heater_pin 2.5 # Pin that controls the heater, set to nc if a readonly thermistor is being defined

HOTEND 2

Hotend temperature control configuration

temperature_control.hotend2.enable true # Whether to activate this ( “hotend2” ) module at all.
temperature_control.hotend2.sensor max31855 #
temperature_control.hotend2.chip_select_pin 0.16 #
temperature_control.hotend2.spi_channel 0 # SPI channel 0 or 1
temperature_control.hotend2.get_m_code 105 #
temperature_control.hotend2.set_m_code 884 #
temperature_control.hotend2.set_and_wait_m_code 889 #
temperature_control.hotend2.designator T1 #
temperature_control.hotend2.max_temp 360 # Set maximum temperature
temperature_control.hotend2.min_temp 0 # Set minimum temperature - Will prevent heating below if set
temperature_control.hotend2.p_factor 25.5 # permanently set the PID values after an auto pid
temperature_control.hotend2.i_factor 1.299
temperature_control.hotend2.d_factor 125
#temperature_control.hotend2.max_pwm 64 # max pwm, 64 is a good value if driving a 12v resistor with 24v.
temperature_control.hotend2.heater_pin 2.7 # Pin that controls the heater, set to nc if a readonly thermistor is being defined

temperature_control.bed.enable true #
temperature_control.bed.thermistor_pin 0.24 #
temperature_control.bed.heater_pin 1.23 #
temperature_control.bed.thermistor EPCOS100K # see
#temperature_control.bed.beta 3974 # or set the beta value

temperature_control.bed.set_m_code 140 #
temperature_control.bed.set_and_wait_m_code 190 #
temperature_control.bed.designator B #

#temperature_control.bed.bang_bang false # set to true to use bang bang control rather than PID
#temperature_control.bed.hysteresis 2.0 # set to the temperature in degrees C to use as hysteresis
# when using bang bang

Switch module for fan control

switch.fan.enable true #
switch.fan.input_on_command M106 #
switch.fan.input_off_command M107 #
switch.fan.output_pin 1.22 #
switch.fan.output_type pwm # pwm output settable with S parameter in the input_on_comand
#switch.fan.max_pwm 255 # set max pwm for the pin default is 255

Servo to change tool

switch.servo.enable true #
switch.servo.input_on_command M340 #
switch.servo.input_off_command M341 #
switch.servo.output_pin 3.25 #
switch.servo.output_type hwpwm # pwm output settable with S parameter in the input_on_comand

switch.servo.pwm_period_ms 20 # (ms) duty cycle

switch.servo.max_pwm 255 # set max pwm for the pin default is 255

Part heater

switch.part_heater.enable true #
switch.part_heater.input_on_command M198 #
switch.part_heater.input_off_command M199 #
switch.part_heater.output_pin 2.4 #
switch.part_heater.output_type digital # just an on or off pin

automatically toggle a switch at a specified temperature.

Different ones of these may be defined to monitor different temperatures and switch different swithxes

useful to turn on a fan or water pump to cool the hotend

#temperatureswitch.hotend.enable true #
#temperatureswitch.hotend.designator T # first character of the temperature control designator to use as
# the temperature sensor to monitor
#temperatureswitch.hotend.switch misc # select which switch to use, matches the name of the defined switch
#temperatureswitch.hotend.threshold_temp 60.0 # temperature to turn on (if rising) or off the switch
#temperatureswitch.hotend.heatup_poll 15 # poll heatup at 15 sec intervals
#temperatureswitch.hotend.cooldown_poll 60 # poll cooldown at 60 sec intervals

Switch module for spindle control

#switch.spindle.enable false #

Endstops

endstops_enable true # the endstop module is enabled by default and can be disabled here
delta_homing true # three axis home together

alpha_min_endstop nc # add a ! to invert if endstop is NO connected to ground
alpha_max_endstop 1.25^ # NOTE set to nc if this is not installed
alpha_homing_direction home_to_max # or set to home_to_max and set alpha_max
#alpha_min 0 # this gets loaded after homing when home_to_min is set
alpha_max 0 # this gets loaded after homing when home_to_max is set
beta_min_endstop nc #
beta_max_endstop 1.27^ #
beta_homing_direction home_to_max #
#beta_min 0 #
beta_max 0 #
gamma_min_endstop nc #
gamma_max_endstop 1.29^ #
gamma_homing_direction home_to_max #
#gamma_min 0 #
gamma_max 239.6 # Calibrated value

alpha_fast_homing_rate_mm_s 50 # feedrates in mm/second
beta_fast_homing_rate_mm_s 50 # "
gamma_fast_homing_rate_mm_s 50 # "
alpha_slow_homing_rate_mm_s 10 # "
beta_slow_homing_rate_mm_s 10 # "
gamma_slow_homing_rate_mm_s 10 # "

alpha_homing_retract_mm 5 # distance in mm
beta_homing_retract_mm 5 # "
gamma_homing_retract_mm 5 # "

alpha_trim 0 # software trim for alpha stepper endstop (in mm)
beta_trim 0 # software trim for beta stepper endstop (in mm)
gamma_trim 0 # software trim for gamma stepper endstop (in mm)

#endstop_debounce_count 100 # uncomment if you get noise on your endstops, default is 100

optional Z probe

zprobe.enable true # set to true to enable a zprobe
zprobe.probe_pin 1.28!^ # pin probe is attached to if NC remove the !
zprobe.slow_feedrate 5 # mm/sec probe feed rate
zprobe.debounce_count 100 # set if noisy
zprobe.fast_feedrate 25 # move feedrate mm/sec
zprobe.probe_height 5 # how much above bed to start probe

associated with zprobe the leveling strategy to use

#leveling-strategy.three-point-leveling.enable true # a leveling strategy that probes three points to define
# planner
# and keeps the Z parallel to that plane
#leveling-strategy.three-point-leveling.point1 75.0,0.0 # the first probe point (x,y) optional may be defined with M557
#leveling-strategy.three-point-leveling.point2 150.0,150.0 # the second probe point (x,y)
#leveling-strategy.three-point-leveling.point3 0.0,150.0 # the third probe point (x,y)
#leveling-strategy.three-point-leveling.home_first true # home the XY axis before probing
#leveling-strategy.three-point-leveling.tolerance 0.03 # the probe tolerance in mm, anything less that this will be
# ignored, default is 0.03mm

leveling-strategy.three-point-leveling.probe_offsets 0,0,0 # the probe offsets from nozzle, must be x,y,z, default is no

                                                               # offset

#leveling-strategy.three-point-leveling.save_plane false # set to true to allow the bed plane to be saved with M500
leveling-strategy.delta-calibration.enable true #
leveling-strategy.delta-calibration.radius 70

Panel

panel.enable false # set to true to enable the panel code
panel.lcd smoothiepanel # set type of panel
panel.encoder_a_pin 3.25!^ # encoder pin
panel.encoder_b_pin 3.26!^ # encoder pin

Example for reprap discount GLCD

on glcd EXP1 is to left and EXP2 is to right, pin 1 is bottom left, pin 2 is top left etc.

+5v is EXP1 pin 10, Gnd is EXP1 pin 9

#panel.lcd reprap_discount_glcd #
#panel.spi_channel 0 # spi channel to use ; GLCD EXP1 Pins 3,5 (MOSI, SCLK)
#panel.spi_cs_pin 0.16 # spi chip select ; GLCD EXP1 Pin 4
#panel.encoder_a_pin 3.25!^ # encoder pin ; GLCD EXP2 Pin 3
#panel.encoder_b_pin 3.26!^ # encoder pin ; GLCD EXP2 Pin 5
#panel.click_button_pin 1.30!^ # click button ; GLCD EXP1 Pin 2
#panel.buzz_pin 1.31 # pin for buzzer ; GLCD EXP1 Pin 1
#panel.back_button_pin 2.11!^ # back button ; GLCD EXP2 Pin 8

pins used with other panels

#panel.up_button_pin 0.1! # up button if used
#panel.down_button_pin 0.0! # down button if used
#panel.click_button_pin 0.18! # click button if used

panel.menu_offset 0 # some panels will need 1 here

panel.alpha_jog_feedrate 6000 # x jogging feedrate in mm/min
panel.beta_jog_feedrate 6000 # y jogging feedrate in mm/min
panel.gamma_jog_feedrate 200 # z jogging feedrate in mm/min

panel.hotend_temperature 185 # temp to set hotend when preheat is selected
panel.bed_temperature 60 # temp to set bed when preheat is selected

Example of a custom menu entry, which will show up in the Custom entry.

NOTE _ gets converted to space in the menu and commands, | is used to separate multiple commands

custom_menu.power_on.enable true #
custom_menu.power_on.name Power_on #
custom_menu.power_on.command M80 #

custom_menu.power_off.enable true #
custom_menu.power_off.name Power_off #
custom_menu.power_off.command M81 #

Only needed on a smoothieboard

currentcontrol_module_enable true #

return_error_on_unhandled_gcode false #

network settings

network.enable false # enable the ethernet network services
network.webserver.enable true # enable the webserver
network.telnet.enable true # enable the telnet server
#network.ip_address auto # use dhcp to get ip address

uncomment the 3 below to manually setup ip address

network.ip_address 192.168.88.222 # the IP address
network.ip_mask 255.255.255.0 # the ip mask
network.ip_gateway 192.168.88.254 # the gateway address
#network.mac_override xx.xx.xx.xx.xx.xx # override the mac address, only do this if you have a conflict


/config-override

; DO NOT EDIT THIS FILE
;Steps per unit:
M92 X88.89000 Y88.89000 Z88.89000
;Acceleration mm/sec^2:
M204 S1500.00000 Z0.00000
;X- Junction Deviation, Z- Z junction deviation, S - Minimum Planner speed mm/sec:
M205 X0.05000 Z-1.00000 S0.00000
M203 X200.00000 Y200.00000 Z200.00000 A150.00000 B150.00000 C150.00000
;Max feedrates in mm/sec, XYZ cartesian, ABC actuator:
;Optional arm solution specific settings and Max Z
;M665 L256.0500 R143.9813 Z239.5
M665 L256.0500 R145.05 Z239.4
;Digipot Motor currents:
M907 X1.70000 Y1.70000 Z1.70000 E1.50000 A1.50000 
;Home offset (mm):
M206 X0.00 Y0.00 Z0.00
;Trim (mm):
M666 X0.000 Y-0.197 Z-0.211
;E Steps per mm:
M92 E400.0000 P57988
;E Filament diameter:
M200 D0.0000 P57988
;E retract length, feedrate:
M207 S3.0000 F2700.0000 Z0.0000 Q6000.0000 P57988
;E retract recover length, feedrate:
M208 S0.0000 F480.0000 P57988
;E acceleration mm/sec²:
M204 E600.0000 P57988
;E max feed rate mm/sec:
M203 E50.0000 P57988
;E Steps per mm:
M92 E400.0000 P39350
;E Filament diameter:
M200 D0.0000 P39350
;E retract length, feedrate:
M207 S3.0000 F2700.0000 Z0.0000 Q6000.0000 P39350
;E retract recover length, feedrate:
M208 S0.0000 F480.0000 P39350
;E acceleration mm/sec²:
M204 E600.0000 P39350
;E max feed rate mm/sec:
M203 E50.0000 P39350
;PID settings:
M301 S0 P25.5000 I1.2990 D125.0000 X255.0000 Y255
;Max temperature setting:
M143 S0 P360.0000
;PID settings:
M301 S1 P25.5000 I1.2990 D125.0000 X255.0000 Y255
;Max temperature setting:
M143 S1 P360.0000
;PID settings:
M301 S2 P10.0000 I0.3000 D200.0000 X255.0000 Y255
;Max temperature setting:
M143 S2 P300.0000
;Probe feedrates Slow/fast(K)/Return (mm/sec) max_z (mm) height (mm):
M670 S5.00 K25.00 R0.00 Z240.00 H5.00

/on_boot.gcode

; Set T0 position to 5.5 using servo
; T1 position is 8.5
M340 S5.5
; Home
G28

Imported from wikidot

(modprobe_SW) #2

Well, it’s embarrassing…
It’s simply the X axis pulley that broke. For my defense ( and for whom may have the same problem), the issue wasn’t that easy to find. When cold, the motor and the pulley were fitting well together, but as soon as the motor heated up, the pulley was slightly released and able to rotate freely in one direction only. Leading to perfect print with a constant shift in the same direction.
What’s broken is the screw thread, I changed the pulley and I’m back on track.

Now that I’m happy I must admit: the quality is way better with smoothieboard the the former solution.

Thank you for reading me, my sweet rubber ducks !