rotary delta + mesh compensation | Strange Z-Lift



  • Hello dc42,

    at the moment i have problems setting up mesh bed-compensation on my rotary delta.
    I use a bed which is 300x300.
    I defined the config.g as follows:

    ; Z-Probe
    M558 P9 C"^zprobe.in" H5 F120 T3000 ; BLTouch connected to Z probe IN pin
    M950 S0 C"exp.heater7" ; create servo/gpio 0 on heater 3 pin on expansion connector
    M280 P0 S90 ; send control signal to BLTouch through servo/gpio 0
    G31 X-20.7 Y3.8 Z7.0 P25 ; Z probe trigger value, offset in relation to nozzle. And trigger height adjustment
    M557 X-140:140 Y-140:140 S20 ; define mesh grid

    My Problem is, after the first Probe the machine does a strange movment to higher the Z Position. It looks like there is no kinematic-transform to lift Z up..
    Could this make sense? Would it be possible to use kinematic-transform here?

    best regards



  • @Egris @dc42 once said that Rotary delta ist more a proof of concept in RRF


  • administrators

    @Egris, I can't think of any reason why mesh probing wouldn't work on a rotary delta. Can you post a link to a video?



  • @dc42 said in rotary delta + mesh compensation | Strange Z-Lift:

    mesh probing

    My mesh probing does not work correctly either, I posted a video earlier in this post https://forum.duet3d.com/topic/20887/rotary-delta-calibration-not-implemented/13?_=1612725679699,
    Also g30 does not work correctly



  • @dc42 yes i will record a short videoclip



  • @dc42 good evening, i uploaded a short Clip where you can see the Mesh Compensatzion Probing.

    https://www.youtube.com/watch?v=zwc3E4wfodQ

    The Z-Lift after the probe triggers did a strange movement.
    I limited the Probing to X 0:145 & Y0:145

    normally i use X -145:145 & Y-145:145 but after the first trigger the effector will move to about x-145 Y145 and crash into the bed.

    maybe you have any idea. It's the last problem I'm trying to solve. Thank you in advance. Great firmware, thumps up



  • @Egris have you tried probing with the Radius Like a Delta?

    Best



  • @PCR I haven't tested this yet, i will give it a try



  • @Egris 2 years ago i used firmware 2.x. There i managed to probe the bed with g29 in a rectangular grid

    https://youtu.be/v46Gh64aN_o?t=65



  • @PCR With M557 R140 S15 got the same result for the Z-Lift as
    M557 X-140:140 Y-140:140 S20..
    Effector moves after first probe trigger to abaot X0 Y140.
    Thanks for your help


  • administrators

    @Egris, can you post a video showing the effect of doing a single G30 move using firmware 3.2 or 3.3beta?



  • @dc42 yes sure, here is a link for probing a single point

    https://youtu.be/DCtipYQOzsc

    -> Home Delta
    -> G1 Z30
    -> G1 X-130 Y-130
    -> G30

    Board: Duet 2 Ethernet (2Ethernet)
    Firmware: RepRapFirmware for Duet 2 WiFi/Ethernet 3.2 (2021-01-05)
    config.g



  • @dc42 After the G30 i did via Webcontrol button Y+5 5mm in Y-Direction. The Effector is moving in Y and Z direction. Could this matter?

    https://youtu.be/W4afA7cdHNI

    Testing it with 3.3 beta gives the same Result


  • administrators

    It looks like the move to raise the probe after it triggers may be using one motor only. Is the Z motor on the left as seen in that video?

    Please post your config.g file so that I can try to replicate it.



  • @dc42 thank you very much for looking into my problem!
    Here is my config.g File

    config.g

    and i did a drawing of the actual wiring layout

    Layout.jpg

    ; Rotary Delta Config
    M669 K10 U190.0 L393.5 R45 A-90.0:46.50 H419.5 X60, Y60, Z60 B212.132
    M666 X0.0 Y0.0 Z-0.28

    I rotated the all 3 arm angles by 60° to line up the X/Y Axis


  • administrators

    @Egris , @Orang_ , I am trying to work out exactly what the problem is. Can you tell me whether mesh bed calibration is working on your rotary delta printers?



  • @dc42 at the moment i cant confirm weather the mesh compensation is working or not. For me it was not possible to finish the grid probing. At the outskirts of the bed the Z-Lift is doing really fast moves to the other side of the bed. What i can confirm is that printing without the compensation is working really well.

    Probing a single point changes / effects the the machine coordinate sytem. After a G30 when i whant to move lets say only in Y-Direction, the move is in Y and Z direction like in that last video.

    Looking forward to solve this Problem together. Thanks alot for looking into it.


  • administrators

    @Egris said in rotary delta + mesh compensation | Strange Z-Lift:

    At the outskirts of the bed the Z-Lift is doing really fast moves to the other side of the bed.

    1. Are you saying that when the machine has been calibrated manually so that good prints are possible, the Z-lift moves during mesh bed probing are not vertical?

    2. What happens if you home the printer, command the nozzle to e.g. 5mm above the centre of the bed, and do G30 S-1 ? Does the Z lift move afterwards go straight up? If so, is it any different if you run G30 S-1 when the nozzle is away from the centre?



  • i looked into the Statemachine for bed-probing in Gcodes 4 but couldn find any hint.
    before the Z-Lift there is called the Function SetMoveBufferDefaults(). Could there be somthing reset?


  • administrators

    PS - one more test:

    1. Move the nozzle to a point off-centre e.g. X0 Y50 Z10. Then command the nozzle up (e.g. to Z50) and check that the movement is vertical. Next, command the nozzle to X0 Y50 Z10 again, but after that send G91 Y50 Z10 (i.e. tell the machine where it is at, giving it the same coordinates that it thinks it is at). Then command the nozzle up to Z50 again and see if the movement is still vertical.


  • @dc42 1. Are you saying that when the machine has been calibrated manually so that good prints are possible, the Z-lift moves during mesh bed probing are not vertical?

    Yes thats true. In the Center of the Bed the Z-Lifts are "more" vertical than they are getting to the edges of the bed.

    If i set my grid-probing to X-145:145 Y-145:145 the first Probe is at X-145 Y-145. Everything works fine until the Z-Lift. When Z is lifted the head moves to abaout X-145 Y145 in a not coordinated move. When it arrives there the head will move to the next grid point at X-125Y-145. On that 2 moves it crashed the nozzle into the bed



  • @dc42 said in rotary delta + mesh compensation | Strange Z-Lift:

    Move the nozzle to a point off-centre e.g. X0 Y50 Z10. Then command the nozzle up (e.g. to Z50) and check that the movement is vertical. Next, command the nozzle to X0 Y50 Z10 again, but after that send G91 Y50 Z10 (i.e. tell the machine where it is at, giving it the same coordinates that it thinks it is at). Then command the nozzle up to Z50 again and see if the movement is still vertical.

    tested it and it works like it should. Z-Movment is vertical


  • administrators

    Thanks; and what about the G30 S-1 tests?



  • i can do that test probably tomorrow. I think i damaged my Z_Probe_In Pin by the 5V Signal of the BLtouch. My Duet2 probably was older than the revision that can handle 5V on that Pin. 🙏 . Is there a possibly to use another analog pin for my Z-Probe? I orderd a spare one


  • administrators

    @Egris said in rotary delta + mesh compensation | Strange Z-Lift:

    i can do that test probably tomorrow. I think i damaged my Z_Probe_In Pin by the 5V Signal of the BLtouch. My Duet2 probably was older than the revision that can handle 5V on that Pin. 🙏 . Is there a possibly to use another analog pin for my Z-Probe? I orderd a spare one

    Are you sure the pin isn't working? The Z probe input pin is fairy tough even on older Duets.

    You can connect the BLTouch to a spare endstop input.


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