# Creating a logarithmic shape/curve

**URL:** <https://discourse.shapr3d.com/t/creating-a-logarithmic-shape-curve/12581>\
**Category:** Modeling Questions\
**Created:** [May 1, 2021, 6:50pm UTC](https://discourse.shapr3d.com/t/creating-a-logarithmic-shape-curve/12581 "2021-05-01T18:50:01Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![greyfox](https://avatars.discourse-cdn.com/v4/letter/g/eada6e/32.png) [@greyfox](https://discourse.shapr3d.com/u/greyfox)\
**Post date:** [May 1, 2021, 6:50pm UTC](https://discourse.shapr3d.com/t/creating-a-logarithmic-shape-curve/12581/1 "2021-05-01T18:50:01Z")

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I’m designing a logarithmic wing-like shape for a project I’m working on. I’m new to CAD, and would like the logarithmic shape to be mathematically precise.

How would I go about drawing this shape?

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**Author:** ![Enginerd](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/enginerd/32/10442_2.png) [@Enginerd](https://discourse.shapr3d.com/u/Enginerd)\
**Post date:** [May 2, 2021, 5:46am UTC](https://discourse.shapr3d.com/t/creating-a-logarithmic-shape-curve/12581/2 "2021-05-02T05:46:31Z")

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You do it exhaustively like I did. Even if there was a method to input equations and get a line to build from it would still be a pain in the ass most programs shit themselves. At least this was my experience when I was modeling the Brachistochrone Curve. I started in Inventor and could not get the damn line to work from the equation. Tbf, I’m not that experienced with that type of thing but I couldn’t not for the life of me figure it out and gave up on that method. I went back to connecting the dots and used Excel to give me the X,Y coordinates for a ton of points along the line and still wasn’t getting it to work since Inventor couldn’t make the line smooth when I was connecting points. It once again just shit itself. I literally got fed up and just found a perfect representation of the curve online that someone wayyyy smarter than me drew and modeled and just traced that with a spline tool until it was perfect.

If you want a perfectly drawn Brachistochrone Curve in this app let me know and I’ll send you the file. I got lucky, it might not be 100% perfect but when I had one side mirror the other it matched at a perfect 180 degree. Plus, most manufacturing methods and material imperfections give you a bunch of leeway.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/2X/5/58d36dd474dea4feb2998034f3dd3462391dec17.jpeg)