Homedelta.g Problem



  • I've started getting
    G28
    Error: G0/G1: target position not reachable from current position errors when homing my mini kossel.
    I think its the homedelta.g file, because if i rem out the line
    ; G1 X0 Y0 F2000 ; centre the head and set a reasonable feed rate
    it goes away but the head moves sideways after homing to X 10.9 Y2.2 which it didnt do before.
    The last changes I did were to th econfig.g file to calibrate the X and Y steps /mm but didnt change anything else.
    How do I stop this?
    My homedelta.g file is
    ; Homing file for RepRapFirmware on Mini Kossel
    G91
    ; use relative positioning

    ;******* Change F250 in the following line to F2500 when you are finished commissioning

    ;******* Change 320 in the following to a higher value if your Kossel has taller towers

    G1 S1 X320 Y330 Z320 F5000 ; move all carriages up 320mm, stopping at the endstops
    G1 S2 X-3 Y-3 Z-3 ; move all carriages down 3mm
    G1 S1 X6 Y6 Z6 F250 ; move carriages slowly up 6mm, stopping at the endstops
    G1 Z-5 F2000 ; down a few mm so that we can centre the head
    G90 ; back to absolute positioning
    ; G1 X0 Y0 F2000 ; centre the head and set a reasonable feed rate



  • what firmware are you on? if its not up to date please update.

    the homing file looks like it was generated for a old version of the syntax.

    please generate an up to date version using.

    https://configtool.reprapfirmware.org



  • Thanks, thats cured it.



  • No Spoke too soon.
    As soon as I put G501 in the config.g file it happens again.
    I'm running
    Firmware Electronics: Duet 0.85
    Firmware Version: 1.26.1 (2020-02-09b1)
    Web Interface Version: 1.22.5

    the config-override.g file generated is
    ; config-override.g file generated in response to M500
    ; This is a system-generated file - do not edit
    ; Delta parameters
    M665 L217.290:217.290:217.290 R106.726 H221.667 B85.0 X-1.474 Y-2.338 Z0.000
    M666 X-7.170 Y6.461 Z0.710 A0.00 B0.00
    ; Heater model parameters
    M307 H0 A90.0 C700.0 D10.0 S1.00 V0.0 B1
    M307 H1 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H2 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H3 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H4 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H5 A340.0 C140.0 D5.5 S1.00 V0.0 B0



  • @Dave-Parry

    post your config.g and your config overwrite



  • Config.g
    ; Configuration file for Duet 0.8.5 (firmware version 1.21)
    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool v3.1.4 on Fri Oct 30 2020 17:48:17 GMT+0000 (Greenwich Mean Time)

    ; General preferences
    G90 ; send absolute coordinates...
    M83 ; ...but relative extruder moves
    M550 P"MiniKossel" ; set printer name
    M665 R105.6 L217.29 B85 H248.92 ; Set delta radius, diagonal rod length, printable radius and homed height
    M666 X-26.4 Y-26.4 Z-26.6 ; put your endstop adjustments here, or let auto calibration find them

    ; Network
    M540 PBE:EF:DE:AD:FE:ED ; set custom MAC address
    M552 P192.168.1.49 S1 ; enable network and set IP address
    M553 P255.255.255.0 ; set netmask
    M554 P192.168.1.1 ; set gateway
    M586 P0 S1 ; enable HTTP
    M586 P1 S0 ; disable FTP
    M586 P2 S0 ; disable Telnet

    ; Drives
    M569 P0 S1 ; physical drive 0 goes forwards
    M569 P1 S1 ; physical drive 1 goes forwards
    M569 P2 S1 ; physical drive 2 goes forwards
    M569 P3 S1 ; physical drive 3 goes forwards
    M584 X0 Y1 Z2 E3 ; set drive mapping
    M92 X83.22 Y77.58 Z79.68 E631.43 ; set steps per mm
    M566 X1200.00 Y1200.00 Z1200.00 E1200.00 ; set maximum instantaneous speed changes (mm/min)
    M203 X18000.00 Y18000.00 Z18000.00 E1200.00 ; set maximum speeds (mm/min)
    M201 X1000.00 Y1000.00 Z1000.00 E1000.00 ; set accelerations (mm/s^2)
    M906 X1000 Y1000 Z1000 E800 I30 ; set motor currents (mA) and motor idle factor in per cent
    M84 S30 ; Set idle timeout

    ; Axis Limits
    M208 Z-0.1 S1 ; set minimum Z

    ; Endstops
    M574 X2 Y2 Z2 S1 ; set active high endstops

    ; Z-Probe
    M558 P1 H10 F120 T2400 ; set Z probe type to unmodulated and the dive height + speeds
    G31 P500 X11 Y0 Z1.663 ; set Z probe trigger value, offset and trigger height
    M557 R85 S20 ; define mesh grid

    ; Heaters
    M305 P0 T100000 B3950 R4700 ; set thermistor + ADC parameters for heater 0
    M143 H0 S120 ; set temperature limit for heater 0 to 120C
    M305 P1 T100000 B4388 R4700 ; set thermistor + ADC parameters for heater 1
    M143 H1 S280 ; set temperature limit for heater 1 to 280C

    ; Fans
    ; M106 P0 S0 I0 F500 H-1 c"Part Cooling" ; set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
    M106 P1 S0 I0 F500 H-1 c"Bed Cooling"

    ; set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned off

    ; Tools
    M563 P0 D0 H1 F0 ; 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

    ; Custom settings are not defined

    ; Miscellaneous
    M575 P1 S1 B57600 ; enable support for PanelDue
    T0 ; select first tool
    M501

    dont have Config overwrite file



  • M92 X83.22 Y77.58 Z79.68

    on a delta its better to use M579
    https://duet3d.dozuki.com/Wiki/Calibrating_a_delta_printer#Section_Correcting_for_small_X_and_Y_scaling_errors

    how did you arrive at those values?

    M666 X-7.170 Y6.461 Z0.710

    your endstops are out by quite some bit. that is a difference of 13mm. this could be why the G1 X0 Y0 does not work at Z216

    try adjusting them so they are on the same level



  • thanks for reply veti
    re M579 do I put the steps/mm back to 80 and insert a line M579 with my values in?

    The end stops are all pretty near in my config file, those you copied are generated by auto cal, but will check again.



  • @Dave-Parry said in Homedelta.g Problem:

    M579 with my values in?

    see
    https://duet3d.dozuki.com/Wiki/Gcode#Section_M579_Scale_Cartesian_axes

    @Dave-Parry said in Homedelta.g Problem:

    those you copied are generated by auto cal, but will check again.

    yes but those are the values used. and they suggest that the endstops are not at the same level.

    alternatively you could change the previous line to

    G1 Z-15 F2000 ; down a few mm so that we can centre the head



  • Have readjusted them, they were'nt that far out but now their within 0.04.
    But still have same problem


  • Moderator

    Have you tried adding vetis command to lower the print head before trying to move to X0 Y0?

    G1 Z-15 F2000 ; down a few mm so that we can centre the head

    Error: G0/G1: target position not reachable from current position

    This error basically means that you're trying to move the head to a position that would require one of the arms to move higher than it physically can. So when trying to move to x0 y0 it would need to raise one arm higher than it can. Dropping all arms down a bit first will help with that.



  • Yes forgot to do that. That solved that, but have developed another problem that the Y axis does'nt always home properly on the first attempt. Particulaly if the head if off centre. Homes ok if I press home a second time.



  • @Dave-Parry increase your home height to the theoretical full travel of the axis.
    So of your homes height is 320mm but your carriage could have to travel 400 if it's fully extended then put 400mm in for each axis.



  • Great that sorted it. Was getting a bit frustrated with it, but hopefully sorted now


  • Moderator

    We're always here to help.



  • Hi Guys,
    I've been getting this error on my mini Kossel delta as well.
    I tried updating the firmware and it's still happening.
    My homedelta.g and config.g are as follows:

    ; homedelta.g
    ; called to home all towers on a delta printer
    ;
    ; generated by RepRapFirmware Configuration Tool v3.1.4 on Tue Nov 10 2020 18:53:43 GMT-0500 (Eastern Standard Time)
    G91 ; relative positioning
    ;*** Slow homing has been configured. Change F180 to F1800 below when your configuration is working
    G1 H1 X265 Y265 Z265 F180 ; move all towers to the high end stopping at the endstops (first pass)
    G1 H2 X-5 Y-5 Z-5 F1800 ; go down a few mm
    ;*** Slow homing has been configured. Change F180 to F360 below when your configuration is working
    G1 H1 X10 Y10 Z10 F180 ; move all towers up once more (second pass)
    G1 Z-5 F2400 ; move down a few mm so that the nozzle can be centred
    G90 ; absolute positioning
    G1 X0 Y0 F2400 ; move X+Y to the centre

    ; Configuration file for Duet WiFi (firmware version 3)
    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool v3.1.4 on Tue Nov 10 2020 18:47:04 GMT-0500 (Eastern Standard Time)

    ; General preferences
    G90 ; send absolute coordinates...
    M83 ; ...but relative extruder moves
    M550 P"MiniKossel" ; set printer name
    M665 R105.6 L215 B85 H250 ; Set delta radius, diagonal rod length, printable radius and homed height
    M666 X0 Y0 Z0 ; put your endstop adjustments here, or let auto calibration find them

    ; Network
    M540 PBE:EF:DE:AD:FE:ED ; set custom MAC address
    M552 S1 ; enable network
    M586 P0 S1 ; enable HTTP
    M586 P1 S0 ; disable FTP
    M586 P2 S0 ; disable Telnet

    ; Drives
    M569 P0 S1 ; physical drive 0 goes forwards
    M569 P1 S1 ; physical drive 1 goes forwards
    M569 P2 S0 ; physical drive 2 goes backwards
    M569 P3 S1 ; physical drive 3 goes forwards
    M584 X0 Y1 Z2 E3 ; set drive mapping
    M350 X16 Y16 Z16 E16 I1 ; configure microstepping with interpolation
    M92 X80.00 Y80.00 Z80.00 E663.00 ; set steps per mm
    M566 X1200.00 Y1200.00 Z1200.00 E1200.00 ; set maximum instantaneous speed changes (mm/min)
    M203 X18000.00 Y18000.00 Z18000.00 E1200.00 ; set maximum speeds (mm/min)
    M201 X1000.00 Y1000.00 Z1000.00 E1000.00 ; set accelerations (mm/s^2)
    M906 X1000 Y1000 Z1000 E800 I30 ; set motor currents (mA) and motor idle factor in per cent
    M84 S30 ; Set idle timeout

    ; Axis Limits
    M208 Z-0.1 S1 ; set minimum Z

    ; Endstops
    M574 X1 S1 P"!xstop" ; X min active high endstop switch
    M574 Y1 S1 P"!ystop" ; Y min active high endstop switch
    M574 Z1 S1 P"!zstop" ; Z min active high endstop switch
    ;M574 Z2 S2 ; configure Z-probe endstop for high end on Z

    ; Z-Probe
    M558 P8 C"zprobe.in" H10 F120 T2400 ; set Z probe type to unmodulated and the dive height + speeds
    G31 P500 X11 Y0 Z2 ; set Z probe trigger value, offset and trigger height
    M557 R85 S20 ; define mesh grid

    ; Heaters
    M308 S0 P"bedtemp" Y"thermistor" T100000 B3950 ; configure sensor 0 as thermistor on pin bedtemp
    M950 H0 C"bedheat" T0 ; create bed heater output on bedheat and map it to sensor 0
    M307 H0 B1 S1.00 ; enable bang-bang mode for the bed heater and set PWM limit
    M140 H0 ; map heated bed to heater 0
    M143 H0 S120 ; set temperature limit for heater 0 to 120C
    M308 S1 P"e0temp" Y"thermistor" T100000 B4388 ; configure sensor 1 as thermistor on pin e0temp
    M950 H1 C"e0heat" T1 ; create nozzle heater output on e0heat and map it to sensor 1
    M307 H1 B0 S1.00 ; disable bang-bang mode for heater and set PWM limit

    ; Fans
    M950 F0 C"fan0" Q500 ; create fan 0 on pin fan0 and set its frequency
    M106 P0 S0 H-1 ; set fan 0 value. Thermostatic control is turned off
    M950 F1 C"fan1" Q500 ; create fan 1 on pin fan1 and set its frequency
    M106 P1 S1 H-1 ; set fan 1 value. Thermostatic control is turned off

    ; Tools
    M563 P0 D0 H1 F0 ; 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

    ; Custom settings are not defined

    ; Miscellaneous
    M575 P1 S1 B57600 ; enable support for PanelDue
    T0 ; select first tool


  • Moderator

    @Duke said in Homedelta.g Problem:

    G1 Z-5 F2400 ; move down a few mm so that the nozzle can be centred
    G90 ; absolute positioning
    G1 X0 Y0 F2400 ; move X+Y to the centre

    If it's the same error as the previous poster then increase the size of that Z move to drop the head further. Try -25 instead of -5



  • @Phaedrux
    That worked perfectly, thank you so much!
    I guess I didn't understand this thread as well as I thought, but now it makes more sense.


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