Constant layer shift along y-axis



  • My cube is not straight. Does anyone have a clue why I may get a constant shift along y?
    It is definitely not a mechanical issue.

    IMG_20191212_231621.jpg



  • Some details of your setup would be useful to know. See https://forum.duet3d.com/topic/5909/guide-for-posting-requests-for-help

    Ian



  • Here is my config

    • ; 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 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 X80.00 Y80.00 Z400.00 E180.00 ; set steps per mm
    • M566 X30.00 Y30.00 Z30.00 E120.00 ; set maximum instantaneous speed changes (mm/min)
    • M203 X6000.00 Y6000.00 Z1200.00 E1200.00 ; set maximum speeds (mm/min)
    • M201 X500.00 Y500.00 Z50.00 E1000.00 ; set accelerations (mm/s^2)
    • M906 X1500 Y1700 Z1500 E1700 I30 ; set motor currents (mA) and motor idle factor in per cent
    • M84 S30 ; Set idle timeout
    • ; Axis Limits
    • M208 X0 Y0 Z0 S1 ; set axis minima
    • M208 X220 Y220 Z220 S0 ; set axis maxima
    • ; Endstops
    • M574 X1 Y1 Z2 S1 ; set active low and disabled endstops
    • ; Z-Probe
    • M307 H3 A-1 C-1 D-1 ; disable heater on PWM channel for BLTouch
    • M558 P9 H10 F120 T6000 ; set Z probe type to bltouch and the dive height + speeds
    • G31 P500 X0 Y0 Z3.0 ; set Z probe trigger value, offset and trigger height
    • M557 X50:220 Y10:180 S42.5 ; 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 S0.3 I0 F500 H-1 ; set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
    • M106 P1 S1 I0 F500 H1 T45 ; set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on
    • M106 P2 S1 I0 F500 H1 T45
    • ; 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

    and some photos. I use linear rails..
    IMG_20191213_205421.jpg IMG_20191213_205427.jpg IMG_20191213_205440.jpg



  • How did you ensure that the Z axis was orthogonal to both X and Y when you built the machine?



  • your frame or at least your axis are not square to each other. is this the first time the printer has been assembled?



  • unrelated, but your belt path is also extremely un-parallel to the frame, which will result in different steps/mm depending on position and also belt tension.



  • Yes it is the first time this printer is assembled in that way. Nevertheless, the belt does not need to be parallel/flat to the extrusion. I rather think that one axis might not be straight, but how this should be possible in a cartesian? Even if y would be tilted 20 degree it would only matter for the first layer.



  • @dgrat said in Constant layer shift along y-axis:

    Nevertheless, the belt does not need to be parallel/flat to the extrusion.

    it does create a small scaling error due to the angle of the belt.



  • Testprint of 2x2x10 cm cube. The higher the print, the less is the y offset. This is a bit weird. I try to re-check the y axis.

    IMG_20191214_152713.jpg



  • I re-assembled the x-axis ensured it is more or less orthogonal and the error disappeared 😄



  • The issue appeared again with a 10x10x2cm cube. Y is not straight.
    Is there a way to log step losses? Printer is square and I supect an issue with the driver?!
    Actually, I never had a similar problem with any of my printers.

    IMG_20191220_135107.jpg IMG_20191220_135126.jpg



  • Did you correct the angle of the Y belt? Perhaps it's binding?



  • Loose pulley, check that the bed is mounted fixed


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