Delta Autocalibration issues



  • So I've run into an odd problem with autocalibration on my delta printer. It was working fine and I decided to dial it in again since I'd changed the bed surface. Now I try to get it to run the autocalibration and it reaches P3 and kinda of bounces on the spot, then gets to the end of calibration and says it couldn't reach all positions, try a smaller radius. So I try a smaller radius and same problem.

    Any suggestions?

    The error is:
    Error: Auto calibration failed because probe point P3 was unreachable using the current delta parameters. Try a smaller probing radius.

    Bed.g is as follows:

    ; bed.g file for RepRapFirmware, generated by Escher3D calculator
    ; 16 points, 7 factors, probing radius: 40, probe offset (0, 38)
    M98 Pdeployprobe.g
    G30 P0 X0.00 Y20.51 Z-99999 H0
    G30 P1 X14.03 Y16.72 Z-99999 H0
    G30 P2 X26.36 Y4.65 Z-99999 H0
    G30 P3 X34.64 Y-20.00 Z-99999 H0
    G30 P4 X13.68 Y-37.59 Z-99999 H0
    G30 P5 X-13.68 Y-37.59 Z-99999 H0
    G30 P6 X-34.64 Y-20.00 Z-99999 H0
    G30 P7 X-26.36 Y4.65 Z-99999 H0
    G30 P8 X-14.03 Y16.72 Z-99999 H0
    G30 P9 X0.00 Y6.90 Z-99999 H0
    G30 P10 X6.79 Y3.92 Z-99999 H0
    G30 P11 X10.52 Y-6.07 Z-99999 H0
    G30 P12 X0.00 Y-20.00 Z-99999 H0
    G30 P13 X-10.52 Y-6.07 Z-99999 H0
    G30 P14 X-6.79 Y3.92 Z-99999 H0
    G30 P15 X0 Y0 Z-99999 S7
    M98 Pretractprobe.g



  • Something to add, this problem seems to go away when I delete config-override.g, but reappears as soon as I run M500



  • post your config and overwrite



  • Config-override is as follows:
    ; config-override.g file generated in response to M500
    ; This is a system-generated file - do not edit
    ; Delta parameters
    M665 L233.658:233.658:233.658 R123.947 H351.931 B70.0 X0.849 Y0.528 Z0.000
    M666 X1.632 Y-1.108 Z-0.524 A0.00 B0.00
    ; Heater model parameters
    M307 H0 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    M307 H1 A340.0 C140.0 D5.5 S1.00 V0.0 B0
    ; Workplace coordinates
    G10 L2 P1 X0.00 Y0.00 Z0.00
    G10 L2 P2 X0.00 Y0.00 Z0.00
    G10 L2 P3 X0.00 Y0.00 Z0.00
    G10 L2 P4 X0.00 Y0.00 Z0.00
    G10 L2 P5 X0.00 Y0.00 Z0.00
    G10 L2 P6 X0.00 Y0.00 Z0.00
    G10 L2 P7 X0.00 Y0.00 Z0.00
    G10 L2 P8 X0.00 Y0.00 Z0.00
    G10 L2 P9 X0.00 Y0.00 Z0.00

    Config is:

    ; Configuration file for Duet Maestro (firmware version 3)
    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool v2.1.8 on Mon Feb 17 2020 13:24:52 GMT-0600 (Central Standard Time)

    ; General preferences
    G90 ; send absolute coordinates...
    M83 ; ...but relative extruder moves
    M550 P"Delta" ; set printer name
    M665 R75 L217 B70 H350 ; 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 P0.0.0.0 S1 ; enable network and acquire dynamic address via DHCP
    M586 P0 S1 ; enable HTTP
    M586 P1 S0 ; disable FTP
    M586 P2 S0 ; disable 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 backwards
    M584 X0 Y1 Z2 E3 ; set drive mapping
    M350 X256 Y256 Z256 E256 I0 ; configure microstepping without interpolation
    M92 X2560.00 Y2560.00 Z2560.00 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 Z0 S1 ; set minimum Z

    ; Endstops
    M574 X2 S1 P"!xstop" ; configure active-low endstop for high end on X via pin xstop
    M574 Y2 S1 P"!ystop" ; configure active-low endstop for high end on Y via pin ystop
    M574 Z2 S1 P"!zstop" ; configure active-low endstop for high end on Z via pin zstop

    ; Z-Probe
    M558 P9 C"zprobe.in" H30 F120 T6000 ; set Z probe type to bltouch and the dive height + speeds
    M950 S0 C"zprobe.mod" ; create servo pin 0 for BLTouch
    G31 P500 X0 Y38 Z4.030 ; set Z probe trigger value, offset and trigger height
    M557 R70 S20 ; define mesh grid

    ; Heaters
    M308 S0 P"bedtemp" Y"thermistor" T100000 B4138 ; 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
    M143 H0 S120 ; set temperature limit for heater 0 to 120C
    M307 H0 B0 S1.00 ; disable bang-bang mode for the bed heater and set PWM limit
    M140 H0 ; map heated bed to heater 0
    M308 S1 P"e0temp" Y"thermistor" T100000 B4138 ; 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
    M143 H1 S280 ; set temperature limit for heater 1 to 280C
    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 H1 T45 ; set fan 1 value. Thermostatic control is turned on
    M950 F2 C"fan2" Q500 ; create fan 2 on pin fan2 and set its frequency
    M106 P2 S1 H-1 ; set fan 2 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
    M501 ; load saved parameters from non-volatile memory



  • @DukeMachine said in Delta Autocalibration issues:

    config.g
    M665 L217

    config override
    M665 L233.658

    L is the length of your diagonal rods. 217 to 233.6 is a HUGE difference. What are they really? (joint center to joint center)



  • I would also change the S7 on the last probe point to S6 or S8 so that the rod length doesn't get changed!



  • @DukeMachine said in Delta Autocalibration issues:

    M350 X256 Y256 Z256 E256 I0 ; configure microstepping without interpolation

    this will cause a lot of problems on a delta.
    please change it to x16 with interpolation

    your thermistor config is wrong 4138 is wrong



  • Well tried changing to S6 and S8, same issue with both. Tried changing to 1/16th microsteps, didn't seem to work. But I deleted config-override again, ran it with 1/16th, L=217, and S6 and it seems to work. So not exactly sure what the issue was. Some combination of the above I guess.

    @Veti My thermistor seems to be reading correctly, what should it be?



  • @DukeMachine S7 can cause some strange effects if your starting figures are off as it make a few best guesses (Not exactly but similar) and the firmware calculates a best fit and will adjust the rod lengths which is bad if you know them to be a certain length so S6 or S8 ignores the rod length in the calculations which is why it generally is better to use those factors.



  • @DukeMachine said in Delta Autocalibration issues:

    My thermistor seems to be reading correctly, what should it be?

    what specific thermistor are you using?
    how do you know that they are displaying the correct temperature? at a temperature of around 200 a wrong setting can easily be off be 20 degrees.



  • As big a pain as this is... if you have an unknown temp sensor, I would suggest checking it in 0C (ice slurry) and 100C (full rolling boil) water.


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