1. Got a question or need help troubleshooting? Post to the troubleshooting forum or Search the forums!

Partially Solved Auto Leveling Touching 6 of 9 points

Discussion in 'Troubleshooting' started by LoneStar, Feb 19, 2016.

  1. LoneStar

    LoneStar New Member

    Joined:
    Feb 19, 2016
    Messages:
    5
    Likes Received:
    0
    This is a printer we have in our office at work. It is 3 months old and we have the upgraded version of the R1.
    It has been working very well. I went to use the printer today and noticed that the lead screw nuts were not connected to the carrage.
    I proceeded to reinstall the guide stops and switches on both sides to the carrage, as they should by.
    The switches are depresses as the carrage sits as it should be. All looks as it should.
    When I run the G28 I centers and the hot end touches the bed.
    When I run the G29 the hot end hits the 1st, 2nd point and moves to the 3rd. It gets to its X axis location and raises. It never lowers to the bed. When it goes to its 4th point it lowers and touches. It also touches the 5th point. The 6th has the same results as the 3rd. Same results with the last row, points 7, 8 and 9.
    The result when printing is horrible as the hot end is too far away from the table.

    So, all three points on the right side of the table never get touched. Infact the head never lowers, only raises.

    Anyone have suggestions to remedy this

    I will get this on video if it helps
     
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,915
    Likes Received:
    7,338
    At the point where the head is raising one or both of the Z axis switches is getting triggered.

    Watch the switches when this is happening. That is what makes it go 'up' it thinks it is on-the-bed.
     
  3. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,915
    Likes Received:
    7,338
    A loose wire to one of the switches could cause the same effect so make sure that is not the case either.
     
  4. LoneStar

    LoneStar New Member

    Joined:
    Feb 19, 2016
    Messages:
    5
    Likes Received:
    0
    I do know about the switches. That is what I thought it was as well. Both switches are engaged and seem to be functioning as they should be. I will check wire connections again but they seemed pretty secure. I didn't see that any of the wires were damaged. That may be an issue as well but I really don't think so.

    Could anything else cause this?
     
  5. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,915
    Likes Received:
    7,338
    The software drives the nozzle up, over to each of the sense points and then DOWN until it senses contact (via a switch).
    So if it is not going down...
     
  6. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,915
    Likes Received:
    7,338
    answer -> it thinks it is already on the bed and the ONLY way it knows that is if a switch toggles or it THINKS one did :)
     
  7. LoneStar

    LoneStar New Member

    Joined:
    Feb 19, 2016
    Messages:
    5
    Likes Received:
    0
    Here is the video I said I would post. This shows the whole g29 auto leveling sequence. I tired to show the switches as well.

     
  8. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
    Staff Member

    Joined:
    Feb 18, 2015
    Messages:
    5,905
    Likes Received:
    3,593
    That usually happens when the X axis is really out of level, the weight of the carriage when on the right side together with the weight of the X axis stepper will pivot the entire axis off the opposite switch so when the auto level gets to that side, it thinks it is already on the bed. What you can do is "paper" level across the X axis and then it has less chance of pivoting. It is not Marlin's fault, it is the poor design of the Mendel printer model the Robo is based on.
     
  9. LoneStar

    LoneStar New Member

    Joined:
    Feb 19, 2016
    Messages:
    5
    Likes Received:
    0
    I used a set of calipers. The X axis bars are only .0013" out of level. Left side is higher. It's not going to get much closer than that.

    I have seen that though where the X axis is way out of alignment and yes, That is pretty much exactly what it does.
    I am very confused why this problem persists. I will be checking the wires for damage tomorrow. I am really not sure it would act this way if the wires were damaged.
     
  10. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
    Staff Member

    Joined:
    Feb 18, 2015
    Messages:
    5,905
    Likes Received:
    3,593
    If the wires were broken it would think the nozzle is on the bed for all 9 points. Your video does not show both switches for every auto-level point, but I bet it is tilted when both steppers are on the right side of the carriage.
     
  11. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,915
    Likes Received:
    7,338
    It could act this way if a connection was loose and getting disconnected in the middle of the auto leveling (since OPEN for a switch = ON THE BED)
     
  12. LoneStar

    LoneStar New Member

    Joined:
    Feb 19, 2016
    Messages:
    5
    Likes Received:
    0
    Ok, I have noticed something this time.
    When the carriage gets to the right side the left side raises up and off of the switch.
    Odd. I have not taken the time, because I am actually at work, to see why it is doing this.
    Mark, I knew you were right but I just wasn't seeing the issue. Well, Found it!
    Thanks for all the responses.
    Waldo, You had it right to.
    Any ideas on why I am having the issue of the X Axis raising on the left side when the carriage is on the right?
    Thinking as I am writing... Does this mean that My X Axis bars could be bent?
     
  13. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
    Staff Member

    Joined:
    Feb 18, 2015
    Messages:
    5,905
    Likes Received:
    3,593
    Mine only does this if the right side is physically higher than the left side. I usually have mine within +- 0.01mm difference from left to right, but sometimes if I press down hard enough on the x carriage, like when inserting or removing filament, on of the steppers will rotate, then I have to relevel it again. Otherwise I never see this phenomenon.
     

Share This Page