Suggestions, Significant bugs and experience upgrading

  • So I could not find a bug report forum so I might as well write everything in one post instead.

    So I decided to start up an prototype printer we built at work a while back but had stood unused for about 1.5-2 years and set it up for use and calibrate it.

    The upgrade first failed when I tried to install the latest immediately but worked when I did the step by step upgrade as the instructions said so that was my mistake and in the end no problem.

    The problems:

    1. The max and min for the print volume had been reversed.
    2. One of the motors directions had been reversed.
      (Those two added together to a rather unexpected behavior with the axis being driven to the defined max and min without stopping between everytime a move instruction was given. see video).
    3. After I got everything working and setup the web interface suddenly complained that it couldn't save a file I was editing and when I tried to open it again it was empty so was every other file.
      When I shut down the printer and checked the card it was suddenly not readable and windows wanted to format it again.

    Some other stuff:
    What is the proper way to define the offset of the Probe in relation to the nozzle?
    I have defined the print volume as the area that the nozzle can reach so that 0:0:0 is when the x and y endstop is triggered and the nozzle is in hight with the print bed. (furthest back and to the right).
    My assumption was that if the probe offset was correctly set it would still move the print head with the previous defined limits and just do a software correction to the heightmap etc so that the height would be correct with regards to the tool position not the probe.
    When I set the offset between the tool and the z-probe with G31 and run G29(and G32) the printer tries to move the probe to the right to reach 0:0 ignoring the triggered endstop and making a whole lot of noise as it was running full speed into the x- stepper.

    Is this a bug or expected behavior and what is the way that corrections to probe offset should be used with the heightmap.

    I think that it is a good idea and helpful with it giving information on how many turns to rotate the screws I am unsure how correct the values can be calculated without the offset set.
    I would also like to be able to have it write out the z trigger heights as it did in previous versions so I can check if the values are looks to be correct.

    G32 interactions with G29.
    The company I work for use a removable build plate with 4 calibration points. We would of course like to use the heightmap to get the best possible result but we would like to be able to use the G32 measurement before print to do a quick check before print and to do some fine adjustments of the base plane the heightmap is applied on.
    It would also be a good thing to be able to use the G32 for a confirmation that the build plate is within limits for what is considered flat and can be corrected for in print. If the build plate fails this test it would be good if an error msg was shown and the print aborted.

    Best regards

    The video
    The Z-axis is set to have a movement range between 0 and 22 mm and it is triggered ahead of time to not have it run into the print head.
    In the video I tell it to go to +1 mm but each time I press +1 it moves to either 0 or 22 depending on what it was at before but it do not stop between those numbers.

    64 characters are to few for topic titles 😕

  • @axel-h

    More info would help as per this

    Then, as you haven't upgraded for 1.5 to 2 years, you should read the release notes that go with the firmware versions, rather than start a post entitled "significant bugs".

  • sorry for using significant my original title was more descriptive but it was to long. Could you remove that from the title as I am apparently unable to .

    I did check the release notes but have not had time yet to read all of them and while I found some of the bugs I have listed I did not find others among them a tendency to format the sd card with all info

  • administrators

    I don't know why your SD card needed reformatting, although the SD card can get corrupted if you power off or reset the Duet while it is writing to the SD card.

    The correct way to define probe offsets is using the X and Y parameters in the G31 command. These values are measured from the head reference point (which is the nozzle, in a single-nozzle machine) to the probe.

    The G29 command is aware of the bed limits, so it will only probe points that are reachable. If it is hitting endstops during G29 then you haven't defined your min or max axis positions correctly.

    G30 Pn Xnn Ynn commands in bed.g are not range checked, because it is sometimes useful to probe outside the normal confines of the bed in bed.g. So it is up to you to choose suitable point, taking account of the probe offset.

  • @dc42
    Thank you for clarifying about the limits.
    Would if be ok for you if I added that info to the gcode page?

    If the G30 Pn Xnn Ynn are to be the coordinate you want the probe to touch are the coordinates in M671 the nozzle coordinates or the probe coordinates with the offset in the calculation.
    Just wanted to check so that the offsets don't carry over onto the M671 part of the equation.

  • I am unsure if the sd card was corrupted when I powered it off but all files showed up as empty and unwritable before I unpowered it so I am not sure exactly what happened.

Log in to reply