First Print and now Strange Homing issue need advice

Discussion in 'Getting Started' started by Thomas Kamsker, Sep 19, 2019.

  1. Thomas Kamsker

    Thomas Kamsker Active Member

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    Hi i did the build and have quite experience with Duet on an Hevo. So i tripple and double checked Toolchange drop works repeatable over days(i had to do business trip in between) then big moment for first print which was almost not on the bed i stopped it then. And now i have a strange problem when i home Y first all good when i home X it runs till the end of side but towards tool docks. When i now click on X+ or - it moves X and Y ? why can anyone give me an hint. ? I played now around with S3 S4 sensibility ?
    Now if i do the hassle and build physical switches would that strange behavior go away ?
    ?
     

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  2. Spoon Unit

    Spoon Unit Well-Known Member

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    So from what you say, I understand that when you home Y, the head moves towards the front of the machine and stops when it hits the the front. This process is managed by homey.g.

    Next when you home X, you see motion in both X and Y. You should check the content of homex.g to see what it prescribes. Mine is adjusted now for physical end stops, but i think I only commented out lines. Here's my homex.g

    Code:
    ; homex.g
    ; called to home the x axis
    
    G91             ; use relative positioning
    
    ;G1 S2 X0.5 Y-0.5 F10000        ; energise
    
    M400             ; make sure everything has stopped before we make changes
    G4 P100            ; wait 400ms
    ;M574 X1 S3         ; set endstops to use motor stall
    
    ;M913 X30 Y30         ; drop motor currents to 50%
    ;M915 H200 Y S4 R0 F0     ; set X and Y to sensitivity 3, do nothing when stall, unfiltered
    
    G1 S2 Z5 F5000        ; lift Z 3mm
    G1 S1 X-400 F3000     ; move left 400mm, stopping at the endstop
    G1 S1 X2 F2000         ; move away from end
    G1 S2 Z-5 F1200        ; lower Z
    G90             ; back to absolute positioning
    
    M400             ; make sure everything has stopped before we reset the motor currents
    G4 P100            ; wait 400ms
    ;M913 X100 Y100         ; motor currents back to 100%
    
    ;M574 X1 S0         ; Define active low and unused microswitches
    What do you have in homex.g?
     
  3. wHack

    wHack Well-Known Member

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    He also said if he hits X+ or X- it moves both X and Y. So at least for X it’s only turning one motor.

    Is Y+ and Y- working correctly?
     
  4. wHack

    wHack Well-Known Member

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    Anyway make sure config.g still has M667 set to S1 for CoreXY. If it’s set to anything else your motion system will behave strangely.

    Also here is the original home.y
    Code:
    ; homey.g
    ; called to home the Y axis
    
    G91             ; use relative positioning
    
    G1 S2 X0.5 Y-0.5 F10000        ; energise
    
    M400             ; make sure everything has stopped before we make changes
    M574 X1 Y1 S3         ; set endstops to use motor stall
    
    M913 X20 Y20         ; drop motor currents to 25%
    M915 H200 X Y S3 R0 F0     ; set X and Y to sensitivity 3, do nothing when stall, unfiltered
    
    
    G1 S2 Z3 F5000        ; lift Z 3mm
    G1 S1 Y-400 F3000     ; move to the front 400mm, stopping at the endstop
    G1 S1 Y2 F2000         ; move away from end
    G1 S2 Z-3 F1200        ; lower Z
    G90             ; back to absolute positioning
    
    M400             ; make sure everything has stopped before we reset the motor currents
    G4 P100            ; wait 400ms
    M913 X100 Y100         ; motor currents back to 100%
    
    M574 X1 S0         ; Define active low and unused microswitches
    
     
    #4 wHack, Sep 19, 2019
    Last edited: Sep 19, 2019
  5. Thomas Kamsker

    Thomas Kamsker Active Member

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    Wow thank you for the fast response ;
    I build the machine from 7-9th of Sept and used the actual https://github.com/e3donline/RepRapFirmware-SD and it worked out of the box Pick tool drop macros worked flawless then i went to business trip and now i just mounted ptfe and tried first print and pick and drop didn't work anymore. i tricked system into taking head and started first print and this lead to strange behavior. (see pictures of test cube )
    then i did Upgrade to newest firmware 2.03 and did use newest version of the sd was changed 2 days ago. And the first pick of tool worked
    but now i tried bench from sd see yourself .
    So it seems that system looses X and Y diagonal
    while it prints each Z level shift.

    So i am direct at standard files of link and first pick by activation T0 did work
    Strange is also
    When i home Y it says -46.50 and when i home X it Says -33 ok
    when i now do a G0 X0 Y0 it works if i do an X150 Y100 as well but after some moves
    X0Y0 is way away as you can see at the prints

    So docking only works if fresh homed X Y then when you pause print it puts back tool which goes wrong as well.
    So i am quite sure changing to physical switch will not change that behavior

    Any suggestions ?
    thx thomas
    here the Home X for reference

    So my Home X
    ; homex.g
    ; called to home the x axis

    G91 ; use relative positioning

    G1 S2 X0.5 Y-0.5 F10000 ; energise

    M400 ; make sure everything has stopped before we make changes
    G4 P100 ; wait 400ms
    M574 X1 Y1 S3 ; set endstops to use motor stall

    M913 X25 Y25 ; drop motor currents to 50%
    M915 H200 X Y S4 R0 F0 ; set X and Y to sensitivity 3, do nothing when stall, unfiltered

    G1 S2 Z3 F5000 ; lift Z 3mm
    G1 S1 X-400 F3000 ; move left 400mm, stopping at the endstop
    G1 S1 X2 F2000 ; move away from end
    G1 S2 Z-3 F1200 ; lower Z
    G90 ; back to absolute positioning

    M400 ; make sure everything has stopped before we reset the motor currents
    G4 P100 ; wait 400ms
    M913 X100 Y100 ; motor currents back to 100%

    M574 X1 S0 ; Define active low and unused microswitches
     

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  6. Thomas Kamsker

    Thomas Kamsker Active Member

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    Now i have played around and switched on DEBUG and out an oc ti usb and see Steppers are loosing steps and i reduced first to 50% speed now to 30% Speed loosing stepps still there but less

    Do you other people have similar issues ? I noticed that the belts are quite stiff compared to my HEVO 300 and ultimaker 3 ? Please some inputs maybe dropping some stepps are ok thx thomas
     
  7. Rob Heinzonly

    Rob Heinzonly Well-Known Member

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    Strange, I did have the same issue just a couple of minutes ago. Did a home all, and the Y-axis was converted, and the X-axis smashed against the tools at the back of the printer. After a couple of reboots and a press on the emergency shutdown button on the web interface, all was back to normal.

    Just as if the machine did forget that it was a corexy printer. :confused:

    I'm currently printing with no problems :cool:
     
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  8. Thomas Kamsker

    Thomas Kamsker Active Member

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    My findings :
    The Head moves (by hand power off situation) have a lot of friction i am not sure that in the corners the small (no name ) motors can overcome this so that is why i loose stepps (loosing steps check )
    But if i try to play around with M915 and tension on the belts (where the friction gets similar to my HEVO 300 ) i dont loose stepps but switchless homing doesn't work
    and this is strange that nobody else has this situation and without repeatability tool changing is not working by any means. it could only be that e3d used other motors (i can't find any labels on them) which are simply to weak
    So i redrawn Gregs switch holder now to my Omron switches (S55GL ;)- and if it works i put it to thingiverse
    we then see if i can find a tension spot which is possible with that motors
    otherwise i will have to change the motors i guess

    any hints would be welcome
    thx thomas

    And that blocks me from drawing an Aero mount !!
     
  9. Rob Heinzonly

    Rob Heinzonly Well-Known Member

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    These motors are used for the X/Y axis:
    • Stepper model: Moon MS17HD2P4200
    • Step size (deg) :1.8
    • Holding Torque: 48.0 N cm
    • Max current per phase: 2.0 amps
    By all means certainly not weak ;). If you want to check yourself: the type number is printed on the bottom of the motor.

    [​IMG]
     
  10. Thomas Kamsker

    Thomas Kamsker Active Member

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    Hi you are right i overlooked it my bad and for a 3d printer it is a strong motor ;)- (I do also small CNC Mills and Lathes ,.. )
     
  11. Thomas Kamsker

    Thomas Kamsker Active Member

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    Spoon Unit and Greg Holloway like this.
  12. Thomas Kamsker

    Thomas Kamsker Active Member

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    Now finally i can say it is not the end switches ...
     

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