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Converting a folder pivot to work as a Sebenza 21 pivot.

Discussion in 'Maintenance, Tinkering & Embellishment' started by EduardoA, Oct 13, 2018 at 3:35 PM.

  1. EduardoA

    EduardoA

    10
    Nov 17, 2016
    I like the concept of Sebenza 21 pivot with bushing, so you can tighten the screw fully.
    It can´t be done to a common pivot cause it will lock the blade, so in general we have to use Loctite after adjusting (even in Sebenza 25).
    I had the idea of making the common pivot allowing fully tightening.
    Sorry if this is old idea, but I´ve never heard about and would like to know if it has already been done. This is what I intend to do:
    The pivot has a female nut part and a male screw part. Put a small steel cylinder of smaller diameter than the hole inside the nut before inserting the screw, so that when fully tight against the cylinder the length will be the correct for the adjusting. This way the screw won´t back off.
    The length of the part has to be guessed, but we can measure top to top of the pivot when adjusted, and top to top when disassembled fully bottomed. The difference is approximately the correct length. The cylinder has to be thinner than the hole to allow it to fall down until the length is sanded to the exact dimension. If it gets stuck, problem.
    Will this idea work?
     
  2. Dangerously

    Dangerously Basic Member Basic Member

    Jan 8, 2013
    I’d be interested in your findings.

    My guess would be that the mating between the cylinder and the pivot screw would be too variable to be able to get the exact same tightness each time. The tolerances wouldn’t be possible and even if it worked once, the end of the screw or the tiny cylinder may be compressed, and not be the same the next time. Or they mate up differently on the next tighten.
     
  3. EduardoA

    EduardoA

    10
    Nov 17, 2016
    I will try in a Cryo that had the spring broken. I´ll try a cylinder made of a piece of spring steel (cut with a dremmel) and flatten the tip of the screw. My fear is the bottom of the female part being of irregular form, conical or angled or full of burrs. Even if a small fine adjustment of tightness be still needed, the screw won´t back off as mine is doing now. If the assembly stays adjusted and doesn´t come loose, it will be opened very few times.
     
  4. Dangerously

    Dangerously Basic Member Basic Member

    Jan 8, 2013
    Don’t forget that the pivot screw on a Sebenza 21 also has a good amount of surface area on titanium. The galling effect helps keep the screw from loosening over time. In a knife with a regular pivot and steel scales, there is no galling to keep the pivot screw from backing out. It might need loctite in any case.
     

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