Could Duet2 cause this? CoreXY skew.



  • I built this coreXY printer about 1 1/2 years ago.
    https://www.thingiverse.com/thing:3382718

    It has been working well. Recently I added a Duex2 to the system. ( this will become pertinent a little later)

    So I have Duet2 wifi 1.04
    RRF3.1.1

    Very recently (I THINK since I tried to add the Duex) it has started to printed very skewed. (see pic).
    20200703_122825.jpg

    The duex I installed had a bad driver5 it was determined. It produced a "driver5 has overheated. And eventually it would shut down". Part of the diagnoses I did was to connect my X axis to the driver5. Obviously it did not work. Motor would not turn. I've since removed the duex from my system.
    Now I am not saying that hooking the motor to the driver damaged the motor. I don't know that. I do know that the time frame is about right.

    What happens is that when the program calls for an X- to X+ motion, the X axis creeps forward, and when it calls for X+ to X- motion it creeps backward.

    The first thing people suggest on a corexy system is to check the belts and I do have new belts and idlers on order. I do have another motor I can swap out but it is a real pain to do so, so I thought I would ask here if there is anything in the duet that could be causing this?

    I have had to add this line to my config to somewhat correct the skew:
    M556 S100 X4.5 Y0 Z0 ; adjust for obtuse XY angle

    Thanks for looking
    George M



  • Are the X and Y axes - i.e the guide rails- square? Belt tension is what squares the rails. In most designs, the belts should be pretty close to equal tension when the X and Y axes are square.

    Save yourself some trouble and expense- motors almost never go bad, and when they do the smell is unmistakeable.

    Are you using steel core belts? They are usually white...



  • @GeorgeM Hi,

    In the following page http://reprapltd.com/reprappro/documentation/commissioning-introduction/calibration-duet/index.html see the section "Orthogonal Axis Compensation", it work for me. I have the same problem in my first build of CoreXY.

    Bye



  • Boy do I feel STUPID!!!! I was doing some calibrations last week (new filament) and forgot that I can't adjust x an y steps like in a cartesian printer. Went back and used same steps for both motors and now all is fine. It's amazing what pops into your head when it's 3 in the morning and you can't sleep!



  • @GeorgeM that’s funny! Glad you figured it out.

    If you would still like to adjust scaling, you can use the M579 command.



  • @bot said in Could Duet2 cause this? CoreXY skew.:

    @GeorgeM that’s funny! Glad you figured it out.

    If you would still like to adjust scaling, you can use the M579 command.

    Thanks bot, that is my next move.


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