19 tpi
Close
Login to Your Account
Results 1 to 10 of 10

Thread: 19 tpi

  1. #1
    Join Date
    Jun 2007
    Country
    UNITED STATES
    State/Province
    Nevada
    Posts
    530
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    66

    Default 19 tpi

    I made this transposing gear for Daryl to cut 19 threads per inch. It is 57/60. The material is delrin. Much easier to deal with than steel for this application where it might be used 10 times in Daryl's entire machining career. For those who might think delrin isn't strong enough, a module 1 (25.4 Dp) gear can take upwards of 8 horsepower in a model helicopter, so the 16 Dp teeth here are plenty, plenty strong.

    The gear ratio for a 20 tpi setting is:

    24/60 times 60/(everything to the leadscrew) and that equals a carriage movement of 1/20 inches per thread. The 60 in the numerator
    and denominator is the 60 tooth idler.

    To increase the 1/20 inches to 1/19 inches multiply by 20/19. To keep both sides of the equation equal multiply the left side by 20/19

    24/60 * 60/(everything else) * 20/19 = 24/60 * 60/(everything else) * 60/57

    which reduces to 24/57 * 60/(everything else)

    So using a 57/60 idler will cut 19 TPI on a 20 TPI setting.

    It goes without saying that one needs to be very careful and concentrate with no distractions when playing around in the gearbox. If a nut is dropped into the bottom of the gearbox it will be a very unhappy day.
    Attached Thumbnails Attached Thumbnails img_0888-copy.jpg   img_0889-copy.jpg   img_0891-copy.jpg  

  2. Likes Zap921, Ray Behner, daryl bane, DJ2 liked this post
  3. #2
    Join Date
    Oct 2018
    Country
    UNITED STATES
    State/Province
    Ohio
    Posts
    214
    Post Thanks / Like
    Likes (Given)
    187
    Likes (Received)
    38

    Default

    Nice job, looks great!

  4. #3
    Join Date
    Mar 2002
    Location
    dallas,tx
    Posts
    2,541
    Post Thanks / Like
    Likes (Given)
    587
    Likes (Received)
    475

    Default

    Fantastic!! Many Thanks! Great info.

  5. #4
    Join Date
    Sep 2010
    Location
    Oklahoma City, OK
    Posts
    4,691
    Post Thanks / Like
    Likes (Given)
    806
    Likes (Received)
    1936

    Default

    Could this be done in a 100/127 ratio for a 12CK?

  6. #5
    Join Date
    May 2009
    Location
    Canandaigua, NY, USA
    Posts
    2,932
    Post Thanks / Like
    Likes (Given)
    144
    Likes (Received)
    1325

    Default

    Any time I need a change gear for my Logan, it gets made out of Delrin. They work great, last near to forever and are much nicer to the gear cutter.

    metric_gearing.jpg

  7. Likes Zap921 liked this post
  8. #6
    Join Date
    Mar 2011
    Location
    Geneva Illinois USA
    Posts
    6,337
    Post Thanks / Like
    Likes (Given)
    2747
    Likes (Received)
    2468

    Default

    And they are smooth and quiet running.

    Tom

  9. #7
    Join Date
    Jun 2007
    Country
    UNITED STATES
    State/Province
    Nevada
    Posts
    530
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    66

    Default

    Conrad is being modest. I use a program he wrote to calculate 4 gear ratios for my hobber. His program calculates to 6 significant digits. It is a lifesaver for helical gears.

    John

  10. #8
    Join Date
    Jun 2007
    Country
    UNITED STATES
    State/Province
    Nevada
    Posts
    530
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    66

    Default

    Cole, I am sure I could come up with a solution for just about any lathe for a metric gear. Send me pictures of your gear train and threading chart.

    John

  11. #9
    Join Date
    Jun 2007
    Country
    UNITED STATES
    State/Province
    Nevada
    Posts
    530
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    66

    Default

    Daryl, here is the problem. You have the wrong Monarch lathe....


    screen-shot-2020-01-28-11.55.52-am.jpg

    Monarch Series 60 (61 also, I would assume?) factory Inch/Metric brochure

  12. Likes daryl bane liked this post
  13. #10
    Join Date
    Mar 2002
    Location
    dallas,tx
    Posts
    2,541
    Post Thanks / Like
    Likes (Given)
    587
    Likes (Received)
    475

    Default

    It was a huge surprise to me that my 59 EE could not cut 19tpi. And before your gear had to use my ...gasp. 25yr old Enco.


Tags for this Thread

Bookmarks

Posting Permissions

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