Announcement

Collapse
No announcement yet.

transposing gear set for rockwell lathe

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • transposing gear set for rockwell lathe

    I have a rockwell 11in lathe model# 25-100 and I am trying to locate a metric transposing gear set or at least a manual for the set so as to make one myself. I have been looking for one on ebay and at machinery dealers for about a year and a half but its' an illusive little mother. Does any know if the gears use a standard presure angle (20, 14-1/2)? that would be nice, although I would like to try my hand at gear cutting at some point. I suppose I could do the calculations and figureout the gearing myself but It would be nice to have a guide. If anyone can help I would greatly appriciate it.

  • #2
    Virtually guaranteed to be a standard pressure angle.

    The fundamental Problem you need to solve is how to add a ratio of 2.54:1 into the gear train. Classically, it's done with a compound gear of 127/100 teeth. (Then you throw in a 2:1 ratio somehow, to get the 2.54:1, but that's pretty easy to arrange.)
    127-tooth and 100-tooth gears are pretty big (and expensive), so sometimes approximations are used that are "close enough" for any sane use. 47/37, for example, is very close.
    ----------
    Try to make a living, not a killing. -- Utah Phillips
    Don't believe everything you know. -- Bumper sticker
    Everybody is ignorant, only on different subjects. -- Will Rogers
    There are lots of people who mistake their imagination for their memory. - Josh Billings
    Law of Logical Argument - Anything is possible if you don't know what you are talking about.
    Don't own anything you have to feed or paint. - Hood River Blackie

    Comment


    • #3
      thanks so much I knew I was over compliating this in my head. 2.54:1 ratio that I can do. and I bet your right about the presure angle I was just worried because I had seen an article about a back gear repair done to a similar machine and the guy was going off about the weird presure angle although those gears were helical and proprietary, alot of the other gears actually have boston gear stamped in them. well I will try that asap Thanks again

      Comment


      • #4
        Here are all the gear combinations between 15 and 100 teeth that will yield a
        ratio of 1.27 with <= 0.5% error.

        Desired ratio = 1.27

        19:15 => 1.266667 (-0.262467%) **
        28:22 => 1.272727 (0.214746%) **
        33:26 => 1.269231 (-0.060569%) **
        37:29 => 1.275862 (0.461580%)
        38:30 => 1.266667 (-0.262467%)
        42:33 => 1.272727 (0.214746%)
        43:34 => 1.264706 (-0.416860%)
        47:37 => 1.270270 (0.021281%) **
        51:40 => 1.275000 (0.393701%)
        52:41 => 1.268293 (-0.134434%)
        56:44 => 1.272727 (0.214746%)
        57:45 => 1.266667 (-0.262467%)
        61:48 => 1.270833 (0.065617%)
        62:49 => 1.265306 (-0.369597%)
        65:51 => 1.274510 (0.355103%)
        66:52 => 1.269231 (-0.060569%)
        67:53 => 1.264151 (-0.460556%)
        70:55 => 1.272727 (0.214746%)
        71:56 => 1.267857 (-0.168729%)
        74:58 => 1.275862 (0.461580%)
        75:59 => 1.271186 (0.093421%)
        76:60 => 1.266667 (-0.262467%)
        79:62 => 1.274194 (0.330201%)
        80:63 => 1.269841 (-0.012498%) **
        81:64 => 1.265625 (-0.344488%)
        84:66 => 1.272727 (0.214746%)
        85:67 => 1.268657 (-0.105770%)
        86:68 => 1.264706 (-0.416860%)
        88:69 => 1.275362 (0.422230%)
        89:70 => 1.271429 (0.112486%)
        90:71 => 1.267606 (-0.188533%)
        91:72 => 1.263889 (-0.481190%)
        93:73 => 1.273973 (0.312803%)
        94:74 => 1.270270 (0.021281%)
        95:75 => 1.266667 (-0.262467%)
        97:76 => 1.276316 (0.497306%)
        98:77 => 1.272727 (0.214746%)
        99:78 => 1.269231 (-0.060569%)
        100:79 => 1.265823 (-0.328915%)

        Regards, Marv

        Home Shop Freeware - Tools for People Who Build Things
        http://www.myvirtualnetwork.com/mklotz
        Regards, Marv

        Home Shop Freeware - Tools for People Who Build Things
        http://www.myvirtualnetwork.com/mklotz

        Location: LA, CA, USA

        Comment


        • #5
          My Rockwell 10" made in 1966 uses gears with a 20 degree Pressure Angle. Hope this helps.
          I cut it twice, and it's still too short!
          Scott

          Comment

          Working...
          X