1. Got a question or need help troubleshooting? Post to the troubleshooting forum or Search the forums!

New Z axis brace... Thought I would share.

Discussion in 'Show and Tell' started by SteveDjarrell, Oct 14, 2015.

  1. SteveDjarrell

    SteveDjarrell Member

    Joined:
    Jan 9, 2015
    Messages:
    98
    Likes Received:
    38
    As I wait to do my lead screw upgrades I decided to expand upon an existing design for a lead screw stabilizer. I wanted more depth ( more grab) and an endcap on the threaded rod side so the brace could not slide down. I also changed the smooth rod side to grab tighter and added some cut thru text. I uploaded it to here

    http://www.thingiverse.com/thing:1072678

    Prints well with no support or a raft. I printed mine at .2mm. I have noticed it does stabilize the lead screw a lot. Not sure if it will help with z ribbing or not but can not hurt.

    -Steve
    brace.JPG
     
    mark tomlinson likes this.
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    22,626
    Likes Received:
    7,234
    Z-ribbing is caused by the couplers/lead screw thread combination.
    Not movement. Replacement of the lead scrws and eliminating the couplers is the fix.

    More details in the main Z ribbing thread and lead screw upgrade thread.

    Nice model though, just don't want people confused over what causes and eliminates the ribbing.
     
  3. WheresWaldo

    WheresWaldo Volunteer ( ͠° ͟ʖ ͡°)
    Staff Member

    Joined:
    Feb 18, 2015
    Messages:
    5,905
    Likes Received:
    3,586
    @SteveDjarrell and @mark tomlinson First nice design, second as Mark mentioned it is all the parts in the Z-Axis that causes the issue. Easiest and cheapest way to fix this is to use solid couplers, like this (example only): 2 x 5mm To 8mm Shaft Coupling Rigid Coupling Coupler Motor Connector Spanner
    [​IMG]

    Since the two lead screws (actually threaded rods) are essentially unsupported at the two ends, there was simply no need to use flexible shaft couplings. There is enough play in the Z Axis Carriages that shaft misalignment is simply not an issue. The Lead screw update really does two things. First it eliminates some of the wobble inherent in the totally unnecessary flexible couplings, and second is that the lead screw suffers from less backlash than the threaded rod. The solid coupler eliminates the first issue that the stepper upgrade solves, the second can be solved via other means.

    Here is an interesting article on leadscrews vs. threaded rods. http://www.protoparadigm.com/news-u...nd-threaded-rod-vs-leadscrews-in-3d-printers/
     
    mark tomlinson likes this.
  4. SteveDjarrell

    SteveDjarrell Member

    Joined:
    Jan 9, 2015
    Messages:
    98
    Likes Received:
    38
    Thank you guys, I am waiting for my parts to come in for my lead screw upgrade. I am aware the is ribbing caused by the coupler flex. This brace does reduce the ribbing a little by limiting the top end wiggle. Ultimately the upgrade and elimination of the couplers is where I am headed, but not everyone has a hundred dollars to drop and this does help a little. It does not eliminate z ribbing but does help a little. Would like to try the solid coupler as well. Thank you for all the information .


    Sent from my iPhone using Tapatalk
     

Share This Page