Results 1 to 5 of 5

Thread: Double start worm gear

  1. #1
    Join Date
    May 2004
    Location
    east Tennessee
    Posts
    43

    Default Double start worm gear

    I was talking to a friend yesterday and he was trying to help cut a double start worm gear on a cnc lathe. They could get close but the lathe did not have enough feeds avilable to cut it exactly and this thing had to be exact. I don't recall the diameter but it was 10 feet long. I never saw one or knew the existed. I have seen double start threads but not worms.
    SOL

  2. #2
    Join Date
    Mar 2005
    Location
    Toronto
    Posts
    6,572

    Default

    never seen one either but why wouldn't it work? thought cutting stuff like that on cnc was a matter of coding, ie the lathe spindle has an encoder so you can control accurately x motion per rev? ie being able to cut any pitch, multiple pitch etc was one of the advantages of a cnc lathe, maybe that's just on newer ones?

  3. #3
    Join Date
    Jan 2003
    Location
    On the Oil Coast,USA
    Posts
    16,824

    Default

    Multiple lead worms are fairly common,I have seen 2,3 and 4 start worms used in gear reducers.I did see a picture of a 6 lead,but not the real animal yet.
    I just need one more tool,just one!

  4. #4
    Join Date
    May 2003
    Location
    52N 122W Western Kanuckistan
    Posts
    40,418

    Default

    Multiple start worms are used in worm and sector steering gearboxes. A multiple start worm can back drive from the wheel to the worm because of the high helix angle. This allows for good "road feel" in a steering system as well as a proper ratio.
    Free software for calculating bolt circles and similar: Origin now settable to bottom left! All values positive. Click Here

  5. #5
    Join Date
    Jan 2003
    Location
    On the Oil Coast,USA
    Posts
    16,824

    Default

    Also In addition to the use Evan mentioned,they typically can be found in low ratio speed reducers,like 10:1 where a 40 tooth wheel and a 4 start worm yield a gear with a large enough contact area to transmit useable torque.
    I just need one more tool,just one!

Posting Permissions

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