The problem with all the tapping

Discussion in 'Tool heads & ToolChanger' started by Andy Cohen, Sep 2, 2019.

  1. Andy Cohen

    Andy Cohen Well-Known Member

    Joined:
    Aug 23, 2019
    Messages:
    216
    Likes Received:
    55
    My experience with ALL polymers is that when under any form of pressure, regardless the polymer, the stuff moves. It moves slow, but it DOES move. As such the whole idea of tapping threads is problematic. Therefore, EVERY part that uses a thread that we have to 3D print will need a redesign!
     
    Kenneth Albanowski likes this.
  2. Kenneth Albanowski

    Joined:
    Sep 9, 2019
    Messages:
    13
    Likes Received:
    6
    I don't have the time to work on the re-design, but I'd definitely prefer (alternative?) models that use heat-set inserts.
     
  3. Spoon Unit

    Spoon Unit Well-Known Member

    Joined:
    Sep 6, 2015
    Messages:
    1,546
    Likes Received:
    478
    Amr likes this.
  4. Andy Cohen

    Andy Cohen Well-Known Member

    Joined:
    Aug 23, 2019
    Messages:
    216
    Likes Received:
    55
    So I am now up to the part where I need to install the tiny grub screws to hold the metal strips in the cable holders and AS I EXPECTED the threads cannot hold the strips. It's not just that it's a relatively small hole or that it is in a polymer (PC) or that the threads are too fine... it's also in the design of the part where the threaded part of the hole is way too short with not enough threads to keep it from stripping.
    I did find a work around without having to take the time away from moving forward on this build to REDESIGN something by inserting the set screw from the other side where there is a lot more thread. Tapping plastic as well as the use of small set screws? Not good.
     
  5. Paul Arden

    Paul Arden Well-Known Member

    Joined:
    Aug 28, 2019
    Messages:
    99
    Likes Received:
    27
    Personally I had absolutely no issues with this part (all 6 required ones worked for me). My parts were PETG rather than PC, so don't know if that made a difference. I had threaded them all the way through the part in my case.

    By the way, when you come to the metal strips, it is massively easier to put them through the sleeves if you push the rounded off end rather than flat end through them, I made a note in the guide about that.
     
  6. Spoon Unit

    Spoon Unit Well-Known Member

    Joined:
    Sep 6, 2015
    Messages:
    1,546
    Likes Received:
    478
  7. Andy Cohen

    Andy Cohen Well-Known Member

    Joined:
    Aug 23, 2019
    Messages:
    216
    Likes Received:
    55
    Yeah...m it's also a heckalot easier to install the strips into the sleeve if you do that first while the cable is easier to straighten out. It seems easiest if you compress the sleeve too so that it balloons on the cable.
     
    Paul Arden likes this.
  8. Andy Cohen

    Andy Cohen Well-Known Member

    Joined:
    Aug 23, 2019
    Messages:
    216
    Likes Received:
    55
    For sure all the grub screws do not have enough thread going from the front, but the back seemed to be OK...
    However, I found another approach which works quite well without the need to a redesign and without the easy-to-lose PITA grub screws. A small shim which slides into the slot with the metal strip locks them in nice and easy and they are easy to remove too.
     
    Michael Pearson likes this.

Share This Page