Results 1 to 4 of 4

Thread: Need help on measuring spur gear

  1. #1
    Join Date
    Jan 2006
    Location
    Indianapolis
    Posts
    166

    Default Need help on measuring spur gear

    I am attempting to measure a change gear from a Grizzly G9972Z 11 x 26 lathe in order to make two mating gears. These gears will be part of a reverse tumbler. What I believe I have determined from an existing spur gear is; 35 tooth, root diameter is 1.281” (32.54mm), outside diameter is 1.452” (36.88mm). Using my 10x magnifier lenses, the pressure angle looks very similar to the chart in machinery’s handbook showing 20 degrees.

    Is this enough information to calculate the dimensions for a 36 tooth mating gear? How do I go about these calculations? I have studied the machinery’s handbook but still do not understand. I would like to make a single point tool for a fly cutter and use a spindexer in the mill to make these gears.
    Thanks
    Gary

  2. #2
    Join Date
    Mar 2001
    Location
    Nottingham, England
    Posts
    15,252

    Default

    Gary,

    From your figures and knowing that the Grizzly is an import take the OD, add 2 to the number of teeth making 37 and divide this into the OD.

    To all intents and purposes it comes to 1 which is 1 MOD the metric equivalent of spur gears.
    1 Mod is equal to 25.4 DP in imperial terms.
    .

    Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.




  3. #3
    Join Date
    Jan 2006
    Location
    Indianapolis
    Posts
    166

    Default

    Thanks John. If I understand correctly, the diametrical pitch then is 25.4. Using this link www.doov.com/cgi-bin/tgc_spurgear.cgi, I input the diametrical pitch as 25.4, number of teeth as 36 and the pressure angle as 20. The program return the other values needed to make the gear.
    Gary

  4. #4
    Join Date
    Mar 2001
    Location
    Nottingham, England
    Posts
    15,252

    Default

    Yes, had a look at the output and that's all you need.
    .

    Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.




Posting Permissions

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