Ender 3 homing and Mesh Grid Compensation



  • Greetings!
    I'm having an issue correcting my z-homing and Mesh Grid Compensation.

    The first problem is when I Home All. The Z will rise several mm, home x and y, move to the center of the bed on y, grinds against x end stop, moves down x slightly, moves to coordinates specified and homes z, raises back up, grinds against x end stop again, then parks at roughly x0 and yMid. I cannot for the life of me figure this out. Attached is my config.g and homeall.g. I have a sensor that is offset from the nozzle at X40 y-2.

    ; Configuration file for Duet WiFi (firmware version 1.21)
    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool on Mon Oct 08 2018 16:54:04 GMT-0600 (Mountain Daylight Time)

    ; General preferences
    G90 ; Send absolute coordinates...
    M83 ; ...but relative extruder moves
    M564 H0 ; Free all axis

    ; Network
    M550 PEnderDuet ; Set machine name
    M552 S1 ; Enable network
    M586 P0 S1 ; Enable HTTP
    M586 P1 S0 ; Disable FTP
    M586 P2 S0 ; Disable Telnet

    ; Drives
    M569 P0 S1 ; Drive 0 goes forwards
    M569 P1 S0 ; Drive 1 goes backwards
    M569 P2 S0 ; Drive 2 goes backwards
    M569 P3 S0 ; Drive 3 goes backwards
    M350 X16 Y16 Z16 E16 I1 ; Configure microstepping with interpolation
    M92 X80 Y80 Z400 E93 ; Set steps per mm
    M566 X1200 Y1200 Z48 E300 ; Set maximum instantaneous speed changes (mm/min)
    M203 X30000 Y30000 Z700 E1500 ; Set maximum speeds (mm/min)
    M201 X500 Y500 Z250 E5000 ; Set accelerations (mm/s^2)
    M906 X400 Y400 Z400 E800 I30 ; Set motor currents (mA) and motor idle factor in per cent
    M84 S300 ; Set idle timeout

    ; Axis Limits
    M208 X0 Y0 Z0 S1 ; Set axis minima
    M208 X172 Y220 Z250 S0 ; Set axis maxima

    ; Endstops
    M574 X1 Y1 S1 ; Set active high endstops

    ; Z-Probe
    M574 Z1 S2 ; Set endstops controlled by probe
    M558 P5 H3 F240 T6000 I1 ; Set Z probe type to switch and the dive height + speeds
    G31 P1000 X48 Y-2 Z-.732 ; Set Z probe trigger value, offset and trigger height
    M557 X-8:172 Y0:220 S20 ; Define mesh grid

    ; Heaters
    M305 P0 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 0
    M143 H0 S120 ; Set temperature limit for heater 0 to 120C
    M305 P1 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 1
    M143 H1 S280 ; Set temperature limit for heater 1 to 280C

    ; Fans
    M106 P0 S0.3 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
    M106 P1 S1 I0 F500 H-1 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned off
    M106 P2 S1 I0 F500 H-1 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned off

    ; Tools
    M563 P0 D0 H1 ; Define tool 0
    G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets
    G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C

    ; Automatic power saving
    M911 S10 R11 P"M913 X0 Y0 G91 M83 G1 Z3 E-5 F1000" ; Set voltage thresholds and actions to run on power loss

    ; Custom settings are not configured

    ; homeall.g
    ; called to home all axes
    ;
    ; generated by RepRapFirmware Configuration Tool on Mon Oct 08 2018 16:54:04 GMT-0600 (Mountain Daylight Time)
    G91 ; relative positioning
    G1 Z2 F6000 S2 ; lift Z relative to current position
    G1 S1 X-225 Y-225 F1800 ; move quickly to X and Y axis endstops and stop there (first pass)
    G1 X5 Y5 F6000 ; go back a few mm
    G1 S1 X-225 Y-225 F360 ; move slowly to X and Y axis endstops once more (second pass)
    G90 ; absolute positioning
    G1 S1 X15 Y17 F6000 ; go to first bed probe point and home Z
    G30 ; home Z by probing the bed

    ; Uncomment the following lines to lift Z after probing
    ;G91 ; relative positioning
    ;G1 S2 Z2 F100 ; lift Z relative to current position
    ;G90 ; absolute positioning


  • administrators

    You can step through each line of your home all.g (cut and paste them one by one into the console) that allows you to tune exactly what behaviour you want from homing. Normally it's best to get homex,y,z working individually and then combine them.



  • I ran through it line by line using G-Code Console. I still do not know were I am going wrong in my homez.g. Moving or swapping the G90 and G91 commands produces similar results. Below is what I have tried using for homez and below that is the result.

    M117 Homing Z ; Inform Z home
    G91 ; All cordinates based on last position
    G1 Z5 F6000 S2 ; lift Z 5mm
    G90 ; All cordinates based on origin
    G1 X62 Y117 ; Move to center of bed (roughly)
    G30 ; Probe straight down

    ;Grinds X end stop
    ;Z probes X0 Y0
    ;Grinds X end stop
    ;Places probe at X62 Y0 Z35 but Head position reads X0 Y0 Z35


  • administrators

    @pratical I am not sure what exactly the problem is. you say a particulat move grinds the X endstop. so why not send a move the moves to the correct position rather than into the X endstop?



  • I meant to say that the result at the bottom happens when G30 is sent. My apologies.


  • administrators

    @pratical said in Ender 3 homing and Mesh Grid Compensation:

    G31 P1000 X48 Y-2 Z-.732

    you have the X offset to 48mm, is that correct? you report that its moving to X62 as well which is weird.

    If you centre the nozzle in X and Y and make a mark on the bed just under the nozzle, then job the axis until the probe is over that mark, the difference in X and Y reading will be your probe offset to setup G31 correctly.


  • administrators

    @pratical said in Ender 3 homing and Mesh Grid Compensation:

    M117 Homing Z ; Inform Z home
    G91 ; All cordinates based on last position
    G1 Z5 F6000 S2 ; lift Z 5mm
    G90 ; All cordinates based on origin
    G1 X62 Y117 ; Move to center of bed (roughly)
    G30 ; Probe straight down

    That Z homing file uses a Z probe for homing. Do you have a Z probe on your machine? If so, have you tested and calibrated it? See https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe.


 

Looks like your connection to Duet3D was lost, please wait while we try to reconnect.