Thanks Thanks:  0
Likes Likes:  1
Dislikes Dislikes:  0
Results 1 to 7 of 7
  1. #1
    3D Printer Noob
    Join Date
    Oct 2017
    Posts
    6
    Post Thanks / Like

    Unhappy Extruder problem clicking and no power

    Two day before I started printing one part which took 8 hours, so I started printing late evening to have it printed early morning. Surprisingly when I came morning to my printer it occurred that filament stopped extruding at 30% of print and printer try to print in air. There were only strange clicking noise from extruder engine, so I thought that it is probably jammed filament. So yesterday evening I spent 4 hours to clean head, unclog and try to purge. All the time the same effect clicking noise and no extruding, but I was able to extrude manually filament when jet was hot. So I decided to check how engine behaves and what I found I was able to stop it keeping by knob in hand. I was even able to reverse it by hand during extruding. And that's it motor have no power to move filament.

    I remembered that I have similar noise already from time to time. So now there is a question: is it motor broken, driver or maybe some change in internal settings?

    I try to investigate a bit and found that there is some problem with DRV8811:

    https://e2e.ti.com/support/applicati.../f/38/t/587666

    Has anybody similar problem?

  2. #2
    Administrator bolsoncerrado's Avatar
    Join Date
    Nov 2014
    Posts
    2,905
    Post Thanks / Like
    First time i heard of the 8811 locking permanently, wow!

    you may have to manually rebail your mobo.... yikes!

  3. #3
    3D Printer Noob
    Join Date
    Oct 2017
    Posts
    6
    Post Thanks / Like
    I have one idea. There is a Digital/A converter on board which is setting Vref to 8811. It could be that software on basis of some measurement decreases Vref and in consequence there is lower current so motor have no enough power. I will check it when I back home.

  4. #4
    Administrator bolsoncerrado's Avatar
    Join Date
    Nov 2014
    Posts
    2,905
    Post Thanks / Like
    Or try an alternate PSU in case yours is dying?

  5. #5
    3D Printer God(dess)
    Join Date
    Nov 2016
    Posts
    1,028
    Post Thanks / Like
    ...and try the other side and see if it behaves likewise.

    Clicking is normally a "stripped filament" at the driver mechanism.
    It carves a trough that lets the driver "freewheel".

    I found that unrecoverable cartridges have a problem with the Bowden tube.
    Their over-mold process that puts the Nylon "caterpillar" track over the Teflon tubing is too aggressive.
    This means the Teflon deformed from the pressure.
    When the filament is driven back and forth for infill or whatever, the filament flattens out more.
    This means the width of the filament no longer fits in the tube, specially when the tube is compromised from the factory.

    I have watched this phenomena over the past year. It is highlighted with diamond fill which causes a lot of "pumping".

    I noticed a definite flat area developing along the filament that was still in the tube when unclogging the system.

    Some clicking is okay. Purge often clicks! But when printing, that should be the exception.
    Some filaments require a little extra heat or is a little harder, and clicking will be more prevalent.
    When it strips completely as described above, it quits feeding but you can push the filament manually and get it to proceed.
    That is the reason for the little window in later cartridges.


    One the hardware end, consider the driver algorithm for the motors are set up for delivering torque, not specifically rotational position.
    You can overcome this torque manually with little effort. The motor has to stop pushing after a certain amount of force.
    That results in the stable pressure level at the nozzle. In other words, it doesn't mean how much filament it -actually- feeds;
    it is the amount of pressure it provides up to a maximum rotational speed.
    If the system is tuned, all the elements function at close to the appropriate rate.
    Filament variation is one of those elements. Restricted movement in the Bowden tube is another element.
    Tube stretch under pressure is a third element. Of course, nozzle temperature is also an element.
    It's a tough dance!

    I think Todd went through something similar. IIRC; It came back to life after a careful reseating of the connections inside the Cube.

    Not sure what your setup was, Tomuro, when the failure occurred but this post is some thought on how this system works and doesn't work.

  6. Likes ztoddman1 liked this post
  7. #6
    3D Printer Noob
    Join Date
    Oct 2017
    Posts
    6
    Post Thanks / Like
    I spent some time today with opened printer (everything on table ) and tried many times with jet purging. At the beginning it do not purge, the same effect like described at first post. So I tried with other nozzle and the same, then I decided to exchange teflon pipe from other cartridge (I still print through original cartridge - time to print extruder HUB ) and surprisingly it started to work. After investigation it occurred that teflon pipe which was not working was a little bit shorter (around 1,5 mm). Probably it caused that filament do not move smoothly to nozzle, but made some bulb between pipe and nozzle and it caused that motor have no power to move it. So I extended a bit teflon pipe which is going inside nozzle and everything started working during purging.

    So I decided that it is time to mount printer back. When printer was ready I check purging again and NO!!! it is not working. I tried the same with other cartridges and the same effect. So I decided that instead of purging I will try test print and WOW! it is alive. It is working even on this first "broken" cartridge.

    And now conclusion:
    1. Cartridge have real problem - shorter teflon in nozzle
    2. In purge procedure extruder motors have less power. As already described on mother board there is D/A which is giving Vref for DRV 8811 drivers, Vref have influence on current given to stepper motors. There is the same leg of D/A chip connected to Vrefs of both extruders drivers - that is a cause why there were the same effect on both extruders with different cartridges.
    3. Purging was working on opened printer because teflon pipe was straight so there was less resistance

    So now I printing Extruder HUB

  8. #7
    3D Printer God(dess)
    Join Date
    Nov 2016
    Posts
    1,028
    Post Thanks / Like
    If the tube in the hot-end is too long, it "sphincters" at the ends.
    Also make sure the tube in the hot-end is not up against a taper, like a chamfered fitting.

 

 

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •