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Cycloidal Gear Generator

maximilian_schommermaximilian_schommer Member Posts: 32 ✭✭
Hi Onshapers!

I just finished writing a cycloidal "gear" drive generator. It creates a cycloidal drive train using mathematically correct cycloid curves. I tried to make the UI intuitive. I hope all of the parameters that you would want to adjust are adjustable, but feedback on that would be amazing. 

Try it out!


Again, any feedback would be appreciated!

Maximilian Schommer


  • philip_thomasphilip_thomas Member, Moderator, Onshape Employees, Developers Posts: 1,381
    Where's our flattener? :)
    Philip Thomas - Onshape
  • konstantin_shiriazdanovkonstantin_shiriazdanov Member Posts: 1,221 ✭✭✭✭✭
    hi, rather handy FS for quick experiments! i'd like to see a sketch with pitch circles for outer and inner gears, and possibly i would propose to change the name of "tooth number" field to "ratio", and can't seems to find a field to set the diameter of inner pin array.
  • maximilian_schommermaximilian_schommer Member Posts: 32 ✭✭
    Thanks @konstantin_shiriazdanov
    You're right, I forgot to add the pin diameter circle to the feature list! Right now it's just half way between the outer bearing diameter and the outer pin diameter, but I'll make it editable! Also, what do you mean by pitch circle for outer and inner gears? Isn't that only useful for meshing gears? 

    Thanks for the feedback!

    Maximliian Schommer
  • konstantin_shiriazdanovkonstantin_shiriazdanov Member Posts: 1,221 ✭✭✭✭✭
    hi, maximillian!
    cycloidal gears are still the kind of gears that relies on kinematics of rolling pitch circles, so i think they bring rather important visual information. at least that may be an option. thank you
  • maximilian_schommermaximilian_schommer Member Posts: 32 ✭✭

    I added the ability to change the radius of the inner pins, and also added pitch circles. The pitch circles are different than what you'd expect for gears since they're dependent on the eccentricity and the number of pins (I think), but the ratios of diameters should be correct. I might have gotten the pitch circles wrong, so don't take my word for it. 

    Thanks again!

    Maximilian Schommer
  • konstantin_shiriazdanovkonstantin_shiriazdanov Member Posts: 1,221 ✭✭✭✭✭
    Thanks, if i remember correctly radius of outer pitch circle for cyclo gear = (u+1)*e, for inner pitch circle = u*e. u is ratio and is equal to number of tooth, e is eccentricity
  • maximilian_schommermaximilian_schommer Member Posts: 32 ✭✭

    Awesome! I did (u)*e and (u*e-e), but fixed it now.  I'm working on some more improvements to it and will push a new release soon!

    Thanks! This is a great FS! We machined a working prototype in plastic: 
  • Evan_ReeseEvan_Reese Member Posts: 1,981 PRO
    this is a pretty old thread, but I've been making icons for some of my favorite features. If you like the icon and have time feel free to add it to your feature or ask me for tweaks. it's here.
    Evan Reese / Principal and Industrial Designer with Ovyl
    Website: ovyl.io
  • CyberphilCyberphil Member Posts: 4 EDU
    This is an awesome FS, and thank you for making this! Using it to try and make a stackable version for use in FRC. 

    One request: show the plotted cycloid sketch after the feature is created. I've been running into a bunch of issues with values not updating when assigning them with variables and having the cycloid sketch there would really help solve a lot of the issues I am running into. 
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