Printing problems with large parts



  • I started a different thread a few weeks ago but it got used for other issues so I'm starting this again. This is a strange one so I'l try to be complete.

    I currently have 2 nearly identical printers both running Duet WiFi and Duex5 boards. The only difference between the two machines is that one has 4 Z motors for leveling and the other has 2. Otherwise they are physically the same with minor configurations changes for the z motor differences.

    These printers have been printing well for several months taking anything I've thrown at them. Then, a few weeks ago one printer would start hesitating and slowing down. XY moment became very jerky. I thought maybe there was a driver heating issue but that possibility was pretty much dispelled in my previous thread. I verified that the other printer was able to print the same file with no issues and I also re-sent the file to the printer and also tried it of an SD card. It was no-go so I ordered replacements for both boards to help with troubleshooting.

    I moved the malfunctioning printer to my workbench and swapped out the Duet WiFi but the problem still occurred. I decided at this point to make a new mounting box for the controller that was better designed for troubleshooting and swapped it out. At this point it seemed that the problem was resolved. The printer was able to print all the test parts I sent to it without issue so I decided that there must have been a bad connection on something.

    Yesterday, the problem returned. Or, I should say, seemed to return. I believe the issue was always there but in the course of troubleshooting I switched to a different part for test printing. I downloaded one of the many calibration parts from Thingiverse and was testing with it. It printed perfectly. All of the parts that I was printing at that point were working well but they were all relatively small parts - less than 150mm square on the print bed. Yesterday's part was 280mm in diameter and it failed every attempt to print it. It printed well on the other printer though.

    So, today I swapped out the Duex5 just because I had one and really had no other ideas. I didn't expect anything as the only things currently connected to this board is an extruder motor and the control for my BLTouch probe. To my surprise, the printer is now working properly even with the large parts. I plan to continue testing with a few large parts and hope that it is actually fixed but I'm a bit confused. What could be causing this board to affect the XY movement? Is it possible that something on the Duex5 is loading signals on the Duet WiFi? Why would it only affect large parts?

    Edit: And, if it turns out the problem is still there as I test it, what else can be causing this behaviour?

    Any help would be appreciated.



  • OK, the problem is still there but it did take longer to occur. It seems to only happen with large parts as it is currently printing a smaller calibration part with no errors. Both boards have been replaced so I don't see it as a problem with them but something is definitely not working correctly. Fortunately the other printer is working well.



  • Is it possible that there is a wiring short that gets nudged into fault when traveling at the extents movement?



  • @phaedrux said in Printing problems with large parts:

    Is it possible that there is a wiring short that gets nudged into fault when traveling at the extents movement?

    At this point I think anything is possible. I’m currently printing various sized circles to try to determine where the problem begins. I know I can print 150 mm diameter without problems but not 275 mm or 250 mm. Trying 225 mm at the moment. I’ll be sure to take a very close look at the cables at things progress.



  • @phaedrux said in Printing problems with large parts:

    Is it possible that there is a wiring short that gets nudged into fault when traveling at the extents movement?

    That would be my best guess too. A bad crimp or some such.............
    @mperdue. Try moving all the cables while it's printing a small part to see if you can induce the error.



  • @deckingman said in Printing problems with large parts:

    @mperdue. Try moving all the cables while it's printing a small part to see if you can induce the error.

    Heck with that, I just replaced the whole harness. It was working last night so I'll give it a good checkout today.

    Thanks for the help, everyone.



  • It seems to still be working so I'm going to call it fixed.


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