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 Technic / 2199
    Gear specs. —Eelco Kooiker
   Hello,, I have a few questions about the Lego Technic Gears. I have tried to draw them in a 3D-CAD program but I can't get the good tooth- shape. (I have made a rack, and used this for "cutting" a gear-tooth in 10 steps and then copied in a circular (...) (24 years ago, 11-Sep-00, to lugnet.technic)
   
        Re: Gear specs. —Geoffrey Hyde
     You should take a look at the ldraw program and the .dat files which accompany it. I have seen gears in there - see how they tackled the problem and take it from there. Also, from looking at my own gears here the teeth are not a straight pyramid (...) (24 years ago, 12-Sep-00, to lugnet.technic)
    
         Re: Gear specs. —Eelco Kooiker
     (...) Yes I have seen it too. (...) I don't know how to look "inside" a .dat-file. (...) I now that. I have used the rack-shape 10 times for making one tooth. Every time some degrees more. It is like the rack "rolls about the gear" (I don't know how (...) (24 years ago, 12-Sep-00, to lugnet.technic)
    
         Re: Gear specs. —Steve Bliss
     (...) .DAT files are just text files, use any text editor to view the code. For information about what all the numbers mean, see the LDraw FAQ, (URL). Question 20 gives you the language definition. Could you post pictures of the results you're (...) (24 years ago, 12-Sep-00, to lugnet.technic)
    
         Re: Gear specs. —Eelco Kooiker
     (...) Thanks (...) I have placed a picture on (URL) is (the begining) of a 16-tooth gear. I have calculate the following specs: * pitch circle = 16mm * module = pi (3.1415.........) As you can see it seams the teeth are to big. On (URL) you can see (...) (24 years ago, 12-Sep-00, to lugnet.technic)
    
         Re: Gear specs. —David Martineau
     (...) Eelco, from what i can see, it seems to me that your gear tooth width is too big. You might want to shorten the distance between the left edge of a tooth and the right edge. You might find they mesh better, but with a characteristic known as (...) (24 years ago, 13-Sep-00, to lugnet.technic)
    
         Re: Gear specs. —Eelco Kooiker
     (...) I want to thank everyone who has given any help. After some trying and measuring I have found the wrong thing: The dedendum circle was to large. (Or, The rack "cuts" not enough) At this moment I have the 16-teeth gear shape. And now I will be (...) (24 years ago, 13-Sep-00, to lugnet.technic)
   
        Re: Gear specs. —Jason S. Mantor
   You might have to take more than 10 cuts with your rack cutter. To getting good involute profiles requires more "machining." "Eelco Kooiker" <eelco@kooiker.demon.nl> wrote in message news:G0qLsq.Hq5@lugnet.com... (...) tooth- (...) gears? (...) (24 years ago, 12-Sep-00, to lugnet.technic)
 

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