Issues with mesh bed calibration, I’m stuck! Help!



  • Printer: Rostock Max v3 (delta), Duet WiFi with the latest firmware, Fsr probing, Borosilicate glass bed, carbon fiber arms, aluminum effector plate. I am probing a 120mm radius circle with probe spacing of 15mm (193 total probe points).

    Here’s a link to some photos if you’d like: https://imgur.com/gallery/BMErj

    I’ve been troubleshooting this printer for about a year so I like to think I’ve gotten pretty good at it, but when it comes to this bed leveling issue I’m absolutely stuck.

    I have horizontal striping of high spots in my height map when I use mesh bed correction. I’m trying to fix this issue because even with the mesh correction on, the high spots are still showing up as thin spots in my first layer.

    What I have tried:
    1. Rotating the bed to see if the stripes follow the rotation of the bed, they do not.

    2. Rotating the effector and seeing if they follow that rotation, again they do not.

    3. Rotating the arms between the axis’s.

    4. I have rotated the mechanics of my printer (x,y, and z belts,carriages,motors), still the exact same height map.

    Has anyone else had this happen to them? Anyone know of anything else I can try out? Anything is appreciated.

    Thanks!


  • administrators

    Stripes along the X direction suggest backlash in the mechanics. If they are worse at the negative X end than at the positive X end, the X tower is worse than the Y tower, and vice versa. Suggestions:

    • check belts and pulleys are tight
    • lubricate the joints, if they are of a type that needs lubrication. Likewise your linear rails or wheeled carriages.
    • increase motor current, if the motors are not getting hot
    • if you have springs connecting the arms together, make sure they are not too tight
    • use G1 S2 commands to move the carriages individually by tiny amounts, and see what is the smallest amount that causes a detectable movement of the carriage. Ideally it will be a single 1/16 microstep


  • How much would you say I should up the current? What’s the limit? I’m not too keen on how steppers work…


  • administrators

    Lookup the model number of your stepper motors on the web to find the maximum rated current. I suggest up to about 85% of that value. If the motors are mounted on plastic parts, you may need to keep the current lower than that, to avoid softening the plastic.



  • Todd,

    I am running a very similar setup to yours and have been facing the same banding problem for a while now. Did increasing the motor current resolve your issue?

    Thanks ahead of time!



  • @wwmotorsports I have not yet tried raising the current, I’m still fighting with it on a few issues so I’m not worrying too much about the striping. Tomorrow I will try raising the current and probing, I’ll keep ya updated!



  • Well, I have a qualified success after all of this time!

    I raised the amperage to 1450 mA in the config file for the 0.9° steppers I got from Ulitbots (rated at 1.68A), and that helped to get rid of the banding substantially.

    After that, I added some 50K diff lube (from RC cars) to the ball joints at the end of my Trick Laser arms and MAN what a difference that made.

    The results of my bed mesh calibration looked nearly identical to yours before these changes, and here is the result now:

    Bed Level Photo

    I have yet to print anything with this result, but it is a huge improvement that I wanted to make sure I shared!

    Happy printing and thanks for the advice dc42!!


 

Looks like your connection to Duet3D was lost, please wait while we try to reconnect.