Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 22

Thread: A puzzle: How to secure worms on their shafts?

  1. #11
    Join Date
    Mar 2017
    Location
    central MA
    Posts
    253

    Default

    The nylon worm is going to be a press fit. The steel worms usually come with a single set screw installed, and a spot drill started at 90*. For most light applications the single set screw is adequate. Tap for a second set screw if needed. In both cases add some thread locking liquid to the threads. For a more permanent installation hold the worm in place with the set screw and drill at 90* for a spring type roll pin. Taper pins work, but are a bit tricky when working with the smaller sizes.

  2. #12
    Join Date
    May 2006
    Location
    East Sussex UK
    Posts
    262

    Default

    Personally I'd prefer a keyway broached down both worms and an appropriate key. Only needs to be a modest size.

  3. #13
    Join Date
    Oct 2014
    Posts
    304

    Default

    After reading the replies so far and considering the problem here is what I think. First for the steel one I like the idea of set screws and flats-no dimple made by the point on the setscrew and more positive lock on the shaft. Loctite too maybe. For the nylon one- a pin through both sides of the hub and shaft, then a split collar, (two piece), to hold the pin in place and compress the nylon onto the shaft. The nylon should be a light press fit to start with too.

  4. #14
    Join Date
    Oct 2014
    Posts
    304

    Default

    Three Phase,I would look into an Erector by Meccano building set for your son. He wouldn't have to taking your drawers then.

  5. #15
    Join Date
    May 2011
    Posts
    1,155

    Default

    Thanks everyone. The hub on my 32dp worm is a little too small for a set screw, so roll pin it will be.

  6. #16
    Join Date
    Oct 2013
    Location
    USA MD 21030
    Posts
    4,691

    Default

    I was thinking about a different kind of worm:

  7. #17
    Join Date
    May 2002
    Location
    SE Texas
    Posts
    11,773

    Default

    The roll pin would work for both steel and nylon (and brass too) and there is little chance for it to work it's way out. I am assuming a metal shaft of course.
    Paul A.

    Make it fit.
    You can't win and there is a penalty for trying!

  8. #18
    Join Date
    Jan 2003
    Location
    Chilliwack, B.C.
    Posts
    11,363

    Default

    I second the idea of a metal collar for the nylon worm. They are usually a press fit, but I've seen lots of them with a pin through the hub and shaft. I would use both. Could be a spring pin, roll pin, or simply a close-fitting pin if the collar is there to keep it in place.
    I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

  9. #19
    Join Date
    Apr 2017
    Location
    Kelowna BC
    Posts
    1,590

    Default

    On my garage door opener, there is a roll pin I think, and a nylon worm, but it is not drilled to mount.
    It has a double notch on the end of the gear, it then slides on the shaft till the notches slide up again the pin.
    I think thrust is controlled by the housing.

    I don't like the 2 sets screw idea , i think it could develop slop and start working back and forth..
    Last edited by 754; 12-06-2018 at 11:07 PM.

  10. #20
    Join Date
    Dec 2009
    Location
    Stevens Point, WI
    Posts
    7,411

    Default

    Like mentioned, every plastic gear I have seen (under a couple inches big) was pressed on or had some sort of glue/chemical bond to the shaft.

    Also like mentioned I'd use a roll pin in the metal one.
    Andy

Posting Permissions

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