G28 Delta towers crash



  • I have a delta and when i run G28 even though limit switches activate in machine specific section on dashboard they keep trying to go past and are trying to run motors past limit switches. these are wired in a active low configuration at the top of the delta towers. i am using a duet smart effector.



  • ; Configuration file for Duet WiFi (firmware version 2.03)
    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool v2.1.8 on Sat May 16 2020 12:10:05 GMT+0100 (British Summer Time)

    ; General preferences
    G90 ; send absolute coordinates...
    M83 ; ...but relative extruder moves
    M550 P"kossel" ; set printer name
    M665 R204 L288 B110 H200 ; 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
    M552 S1 ; enable network
    M586 P0 S1 ; enable HTTP
    M586 P1 S0 ; disable FTP
    M586 P2 S1 ; enable Telnet

    ; Drives
    M569 P0 S0 ; physical drive 0 goes forwards
    M569 P1 S0 ; physical drive 1 goes forwards
    M569 P2 S0 ; physical drive 2 goes forwards
    M569 P3 S0 ; physical drive 3 goes forwards
    M584 X0 Y1 Z2 E3 ; set drive mapping
    M350 X16 Y16 Z16 E16 I1 ; configure microstepping with interpolation
    M92 X160.00 Y160.00 Z160.00 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 X2000 Y2000 Z2000 E1800 I30 ; set motor currents (mA) and motor idle factor in per cent
    M84 S30 ; Set idle timeout

    ; Axis Limits
    M208 Z0 S1 ; set minimum Z

    ; Endstops
    M574 X2 Y2 Z2 S0 ; set active low and disabled endstops

    ; Z-Probe
    M558 P0 H5 F120 T6000 ; disable Z probe but set dive height, probe speed and travel speed
    M557 R100 S20 ; define mesh grid

    ; Heaters
    M305 P0 T100000 B4138 R4700 ; set thermistor + ADC parameters for heater 0
    M143 H0 S120 ; set temperature limit for heater 0 to 120C
    M305 P1 T100000 B4138 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 H0 T30 ; set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned on
    M106 P1 S1 I0 F500 H1 T45 ; set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on

    ; 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



  • Set M574 to S1


  • administrators

    Please post your homedelta.g file too.

    What firmware version are you using?



  • Hi David, I am using the firmware:
    Duet WiFi 1.02 or later (duetwifi102)
    Firmware: RepRapFirmware for Duet 2 WiFi/Ethernet 2.05.1 (2020-02-09b1)
    Duet WiFi Server Version: 1.23



  • ; homedelta.g
    ; called to home all towers on a delta printer
    ;
    ; generated by RepRapFirmware Configuration Tool v2.1.8 on Sat May 16 2020 12:10:05 GMT+0100 (British Summer Time)
    G91 ; relative positioning
    G1 H1 X265 Y265 Z265 F1800 ; 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
    G1 H1 X10 Y10 Z10 F360 ; move all towers up once more (second pass)
    G1 Z-5 F6000 ; move down a few mm so that the nozzle can be centred
    G90 ; absolute positioning
    G1 X0 Y0 F6000 ; move X+Y to the centre



  • @rodek wouldn't that persume they are active when high?


  • administrators

    I didn't see anything wrong with your configuration and homing files.

    I suspect that you have swapped a couple of motor or endstop cables over. Use G91 followed by G1 H2 Xnnn moves to identify which tower has the X motor. Then check that when you trigger the endstop on that tower, M119 shows that it is the X endstop that is triggered. Repeat for Y and Z.



  • @dc42 Cheers David, the endstops seem to trigger and are confirmed under endstop status under machine specific tab.



  • does it matter which tower is the x , y and z on a delta as long as it goes in a clockwise direction?



  • I assume it does matter in the way the endstops correlate to the towers.

    It may just be best practice to call the left tower "X", the right one "Y", and the back one "Z", but it really does help in preventing (or at least resolving) this type of issues.


  • administrators

    @chris said in G28 Delta towers crash:

    @dc42 Cheers David, the endstops seem to trigger and are confirmed under endstop status under machine specific tab.

    What I was trying to as was: Is the endstop that shows as X when triggered on the same tower as the motor that moves when you command X movement with a G1 H2 Xnnn move?

    Instances of the behaviour you describe are typically caused by the motor and the corresponding endstop (e.g. X motor and X endstop) not being on the same tower.



  • @dc42 Cheers david X and Y limit switches got swapped


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