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Crankshaft Taper?

Discussion in 'The Garage' started by Jim, Jan 10, 2019.

  1. Jim

    Jim "No...Try not. Do ... or do not. There is no try." Top Contributor XS650.com Supporter

    Anybody ever measure the taper angle of the crankshaft rotor end? I need to make and indexing tool. I could take one of my motors apart I suppose... but ... any of you ever measure one?
     
    gggGary likes this.
  2. gggGary

    gggGary Horsepower; just noise 'til the tire hooks up. Top Contributor XS650.com Supporter

    not quite the question you asked but lemme look in the bins I have some "apart" cranks, If I knew last week...............
     
    Last edited: Jan 10, 2019
    Jim likes this.
  3. gggGary

    gggGary Horsepower; just noise 'til the tire hooks up. Top Contributor XS650.com Supporter

  4. lakeview

    lakeview XS650 Guru Top Contributor XS650.com Supporter

    A related question: are the Woodruff keys to fit available anywhere? All Princess Auto had was an 12" length of key stock.
     
    Jim likes this.
  5. gggGary

    gggGary Horsepower; just noise 'til the tire hooks up. Top Contributor XS650.com Supporter

    someone should measure one up.
     
    Jim likes this.
  6. gggGary

    gggGary Horsepower; just noise 'til the tire hooks up. Top Contributor XS650.com Supporter

  7. gggGary

    gggGary Horsepower; just noise 'til the tire hooks up. Top Contributor XS650.com Supporter

    Here's what I came up with
    Set up on the lathe trued to with in .001 measured at the midpoint of the runout.
    .100" in 1.000" of travel. this is side or .200" diameter reduction over an inch
    DSCN3570.JPG

    semi related;
    I Ohmed the rotor I pulled off to get lakeside's :whistle: woodruff key dimensions. a "looks good" late model rotor,
    Cold about 28F 4.9 ohms
    room temp 65F 5.5 ohms
    Warmed on wood stove 130F 6.1 ohms
    back outside for a while 39F 5.1 ohms

    Man I really want to get a 2 axis DRO set up!
     
    TwoManyXS1Bs, Mailman and Jim like this.
  8. Jim

    Jim "No...Try not. Do ... or do not. There is no try." Top Contributor XS650.com Supporter

    Thanks Gary :D
     
    lakeview likes this.
  9. gggGary

    gggGary Horsepower; just noise 'til the tire hooks up. Top Contributor XS650.com Supporter

    a few more numbers
    total length of taper 1.11"
    major diameter .97
    minor diameter .76
    these show the angle I came up with. I'll let 2M see if the numbers more or less jive.

    DSCN3578.JPG DSCN3577.JPG
     
  10. Jim

    Jim "No...Try not. Do ... or do not. There is no try." Top Contributor XS650.com Supporter

    Thanks buddy!!

    IMG_20190111_165413.jpg



    IMG_20190111_165446.jpg
     
  11. Mailman

    Mailman Hardly a Guru Top Contributor

    You guys are amazing. I have machine envy. :D
     
    FB71 and Jim like this.
  12. gggGary

    gggGary Horsepower; just noise 'til the tire hooks up. Top Contributor XS650.com Supporter

    Mailman, MaxPete and Signal like this.
  13. Jim

    Jim "No...Try not. Do ... or do not. There is no try." Top Contributor XS650.com Supporter

    I set it from the tool slide. My "older than me" Atlas ain't as accurate as yours. Looks like 'bout 5.4°
    Fit is good enough... :rolleyes:

    IMG_20190111_202734.jpg
     
  14. Jim

    Jim "No...Try not. Do ... or do not. There is no try." Top Contributor XS650.com Supporter

    ....... jig for verifying timing mark.

    IMG_20190111_203731.jpg

    IMG_20190111_203750.jpg
     
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  15. Signal

    Signal XS650 Junkie

    Thank you gentlemen for the info on the taper. I want to cut an internal taper but think I will need a smaller boring bar.
    How does you use the jig Jim.
     
    Jim likes this.
  16. Jim

    Jim "No...Try not. Do ... or do not. There is no try." Top Contributor XS650.com Supporter

    I need to add a pointer.... It's mainly just to verify I didn't screw up when I press the rotor back together.

    IMG_20190111_203750.jpg
     
    gggGary, Mailman, Signal and 2 others like this.
  17. Jim

    Jim "No...Try not. Do ... or do not. There is no try." Top Contributor XS650.com Supporter

    Yeah.... like I know what I'm gonna do from one moment to the next... :confused::rolleyes:
     
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  18. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    Been researching this taper conundrum.
    Such an odd taper, different from tooling and propshaft standards.

    Used gggGary's numbers from post #10.
    RotorTaper.jpg

    It shows a 10.8° included angle, 5.4° tooling angle.

    Ggggary, if you do it with arctan of (.97 - .76) / 1.11 , it'll be close to 5.4°.

    I found varieties of motorcycle tapers, 5°, 6°, 7°, 7.5°, 8.5°.
    This one comes close to the 1:5 standard, 11.42° included angle, 5.71° tooling angle.
    Probably should double-check gggGary's measurements.

    Then I came across some old references to accessory and pulley tapers,
    calling out an old standard of 3:16.

    That's 3/16" per inch, or 2.25" per foot.
    The tooling setup would be 3/32" per inch, or 1.125" per foot.

    Which works out to 10.76° included angle, 5.38° tooling angle.

    It's so close that I'd hang my hat on it...
     
    Last edited: Jan 22, 2019
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  19. gggGary

    gggGary Horsepower; just noise 'til the tire hooks up. Top Contributor XS650.com Supporter

    2M to the rescue
    RangerSilver.jpg
    thanks!
    the .100 in 1.00 was much more carefully arrived at, reset and remeasured a couple times, it agreed with the measured angle quite closely. the 1.11" with the 2 diameters were just handheld caliper pulls. :shrug: But i'm just a hacker, better lucky than skilled I guess.
     
    Last edited: Jan 11, 2019
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