Lessons Learned

Discussion in 'Getting Started' started by Andy Cohen, Oct 4, 2019.

  1. wHack

    wHack Well-Known Member

    Joined:
    Aug 20, 2019
    Messages:
    96
    Likes Received:
    16
    @Ntesla66 What resolution are you printing at? Are you slowing down your speed on small layers? What are you doing for cooling?
     
  2. Andy Cohen

    Andy Cohen Well-Known Member

    Joined:
    Aug 23, 2019
    Messages:
    217
    Likes Received:
    57
    Layer height is .25mm.
    I turned off slowing it down on small tool paths so that it goes the full speed all the time and that helped quite a bit. Downward fan is at 100%.

    In the meantime I have a 95cm cable on order for the Zesty Nimble that I have. Barbles mount works quite well for the nimble on to the top of a tool and I will temporarily mount the stepper bracket to the back on to the extrusion (I removed the back panel). Hoping for a much better result then what we are seeing with these Bowdens.
     
  3. wHack

    wHack Well-Known Member

    Joined:
    Aug 20, 2019
    Messages:
    96
    Likes Received:
    16
    Thanks Andy, but I was asking Ntesla66.

    If you are mounting a Nimble mount the motors to the sides instead of the back if you can. It will seriously decrease the amount of error due to rotational position.
     
  4. Ntesla66

    Ntesla66 Active Member

    Joined:
    Sep 9, 2019
    Messages:
    34
    Likes Received:
    31
    @wHack , These are my current settings
     

    Attached Files:

  5. Ntesla66

    Ntesla66 Active Member

    Joined:
    Sep 9, 2019
    Messages:
    34
    Likes Received:
    31
    @wHack This... and I changed back to s3d and put fresh rolls of pla in the machine. Z3_1-min.jpg
     
  6. wHack

    wHack Well-Known Member

    Joined:
    Aug 20, 2019
    Messages:
    96
    Likes Received:
    16
    I would work on dialing in single material prints before you do multi material prints. Once you have it pretty reliable on single material prints then you can tackle a good prime sequence which should fix all of those things sticking out of the print.
     
  7. wHack

    wHack Well-Known Member

    Joined:
    Aug 20, 2019
    Messages:
    96
    Likes Received:
    16
    I also am about to go out of town so don’t have time to be much help right now. Hopefully someone else on the forums can help guide you to more reliable single material prints.
     
  8. Andy Cohen

    Andy Cohen Well-Known Member

    Joined:
    Aug 23, 2019
    Messages:
    217
    Likes Received:
    57
    I would say your method of purge/wipe is ineffective.
     
    Spoon Unit and Ntesla66 like this.
  9. Ntesla66

    Ntesla66 Active Member

    Joined:
    Sep 9, 2019
    Messages:
    34
    Likes Received:
    31
    I spent all last night printing "single" extrusion prints from multiple heads... and they are fine. Outstanding motion system but then again I love Duet 3d products and Trinamic drivers, I use them on all my other printers. Not so enamored with bowden tubes whose length is the bleeding edge of "what's a retraction" and I used capricorn tubing to assuage the friction pixies but to no avail. My day job is acoustic engineering and brother I can tell you, there are resonances all over this machine. I think that the vibrations transferred to the back panel are at least part of the problem of the extruder tension screws backing off all the time. No problem, I can figure this out. It won't look like this printer when I get done with it, but I'll figure it out. Thanks.
     
    Greg Holloway and Spoon Unit like this.
  10. wHack

    wHack Well-Known Member

    Joined:
    Aug 20, 2019
    Messages:
    96
    Likes Received:
    16
    Also I really recommend the paperclip for your brush. I have one and once I got it set up right it catches my purge strings every time.
     
  11. Cam_Motion

    Cam_Motion Active Member

    Joined:
    Jan 6, 2019
    Messages:
    30
    Likes Received:
    2
    Do you have any thoughts you'd like to share on how the design of the machine could be improved to reduce the print artefacts caused by the resonances?
     
    #31 Cam_Motion, Oct 22, 2019
    Last edited: Oct 22, 2019
  12. Andy Cohen

    Andy Cohen Well-Known Member

    Joined:
    Aug 23, 2019
    Messages:
    217
    Likes Received:
    57
    I don't know about the resonances, but for sure the machine will be significantly improved once we RID it of the Bowden extruders. I'm still waiting on parts for my Nimble.
     
  13. Cam_Motion

    Cam_Motion Active Member

    Joined:
    Jan 6, 2019
    Messages:
    30
    Likes Received:
    2
    I've been working on a modified frame to improve the stiffness. I think the Hermes would be an improvement but with it being heavier I wonder if it will make the resonance problems at the same speed worse?

    https://cad.onshape.com/documents/2...7cf1d3c5ac23e2a8fa/e/acd3898f8b41773cca420cac e3dmotionmod.png
     
  14. mhe

    mhe Well-Known Member

    Joined:
    Sep 5, 2015
    Messages:
    279
    Likes Received:
    76
    I think especially with the frame stiffened like this, the extra weight of the Hermes shouldn't be a problem. And even if, M593 will be your friend.
     
    Ntesla66 likes this.
  15. Ntesla66

    Ntesla66 Active Member

    Joined:
    Sep 9, 2019
    Messages:
    34
    Likes Received:
    31
    I think the frame is really pretty good. It's all those panels ringing like drum heads. They pick up any of the vibrations in the system and amplify them. Try this, with a print going place one hand on each side of the enclosure in the middle of the panels and push inward GENTLY ...listen to the overall noise level while you do this. Mine gets much quieter when I do this. I have a 35670a dynamic signal analyzer. I'm going to hook it up to some accelerometers and measure some vibration frequency responses. I'll do this after I get all my direct drives working, because all of the spool holders will be moving out of the print chamber to up on top.
     
    Nibbels likes this.
  16. Cam_Motion

    Cam_Motion Active Member

    Joined:
    Jan 6, 2019
    Messages:
    30
    Likes Received:
    2
    I know you've had other things to deal with recently but when you get back to things could you do some measurements on the Z axis as I think this may be the main source of the problems we've been seeing.
     
    Ntesla66 likes this.
  17. Andy Cohen

    Andy Cohen Well-Known Member

    Joined:
    Aug 23, 2019
    Messages:
    217
    Likes Received:
    57
    Back on topic...
    Lessons learned...
    Cut the filament tip square, no angle at all and the titans won't jam during load.
    PETG seems to work best with small tool paths and with lots of tool changes. Better then PLA and better then ABS, but not all PETG is the same. One kind of PETG I got from filaments.ca won't wipe/purge reliably.
    ABS did work well, but enclosing and heat soaking with this setup is a challenge.

    I got the last part for the Nimble today. I may try to install later today.
     

Share This Page