2 Mistakes

Discussion in 'Mistakes, Blunders and Boo Boos' started by 1Fitch, Jan 24, 2016.

  1. Jan 24, 2016 #1

    1Fitch

    1Fitch

    1Fitch

    Member

    Joined:
    Jun 11, 2015
    Messages:
    11
    Likes Received:
    1
    Mistake #1

    For Christmas my girlfriend wanted to get me a chucking reamer set I had looked at at one one point. Because I have been wanting to cut gears I asked for a dividing head instead. I directed her to the BS1 type that Grizzly sells. I knew there was a problem when I tried to move it and it weighed what felt like seventy pounds. I barely have 6" between centers. A BS0 type dividing head would have been much more suitable for my RF25 mill.

    Mistake #2

    I have cut a couple of gears using my new (over sized) dividing head. Once I understood the formulas involve for gear cutting and watching Tubalcains videos a few times I thought I had it down. The first couple of good gears I cut were all direct indexed. When I needed to cut a 35 tooth gear is when the trouble started. I'm 46 now and haven't worked with fractions for over 26 years. My calculation was 40/35 = 1 5/40 = 1 1/8 instead of the correct 1 5/35 = 1 1/7! I bolted on a plate with a 16 hole circle and away I went with 1 turn and skip two spaces. When I got to my last gear tooth, I was shocked!
    To make this gear blank on my Sherline lathe requires I use riser blocks and care because this is really large for this lathe.

    Back to 6th grade math class I go.:fan:
    Enough of what a dummy I am for now.

    Paul
     
  2. Jan 24, 2016 #2

    Swifty

    Swifty

    Swifty

    Well-Known Member

    Joined:
    Mar 6, 2012
    Messages:
    2,253
    Likes Received:
    811
    The dividing head should have come with a chart showing which plate to use and how many turns and holes for the required number of divisions.

    Paul.
     
  3. Jan 24, 2016 #3

    portlandron

    portlandron

    portlandron

    Well-Known Member

    Joined:
    Jan 4, 2010
    Messages:
    222
    Likes Received:
    12
    Anyone that has ever cut a gear has a few "mistakes"

    Regarding the dividing head that's not a mistake. Look at it as you have a dividing head to fit the new lathe that will some day replace your Sherline.
     
  4. Jan 24, 2016 #4

    xpylonracer

    xpylonracer

    xpylonracer

    Well-Known Member

    Joined:
    Dec 23, 2010
    Messages:
    218
    Likes Received:
    51
    Hi Paul

    To save yourself a lot of headaches with which index wheel and number of divisions to use visit Marv's site and check for a simple dividing program, I can't remember the exact program name but there many there to choose from and most have a description, link to the site is
    http://www.myvirtualnetwork.com/mklotz/

    Emgee
     
  5. Jan 29, 2016 #5

    1Fitch

    1Fitch

    1Fitch

    Member

    Joined:
    Jun 11, 2015
    Messages:
    11
    Likes Received:
    1
    Thanks for the replies guys. Swifty, I found the chart you were referring to. I would have never thought to read the directions!:wall: Emgee, thanks for the link. There is good stuff there. I appreciate every ones input.

    Paul
     
  6. Jan 29, 2016 #6

    bazmak

    bazmak

    bazmak

    BAZMAK

    Joined:
    Dec 12, 2012
    Messages:
    1,967
    Likes Received:
    1,105
    Anyone who has not made a mistake had not made anything
    Some are simple and costly and it hurts at the time
     
    charlesfitton and gphunt like this.
  7. Jan 29, 2016 #7

    mcostello

    mcostello

    mcostello

    Member

    Joined:
    Sep 6, 2011
    Messages:
    271
    Likes Received:
    26
    Some You remember the rest of Your life.;)
     
    gphunt likes this.
  8. Jan 31, 2016 #8

    1Fitch

    1Fitch

    1Fitch

    Member

    Joined:
    Jun 11, 2015
    Messages:
    11
    Likes Received:
    1
    That's how we roll. Learn from our mistakes and keep moving forward. Thank you guys for taking time to read/respond to my post. You guys that have much more machining experience/knowledge than me are always an asset here on the forums.

    Paul
     

Share This Page