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Building a curve with an equation


New member
Hey Guys,

I have been trying to build the evolvent of a Gear in CATIA V5 and I want to use the following formulas for the curve:
x = R*(sin(f)-f*cos(f))
y = R*(cos(f)+f*sin(f))
Where x and y are the coordinates,R is a know konstant and f is a number going from 0 to a specific number (which will be defined by another formula, but lets say for this case it will be =0.67).
Can any one please tell me how to do it?

Thank you!


Super Moderator
I've seen several videos and tutorials on the internet explaining how to make a CATIA curve based on an equation.

I found this one (using the same equations as yours) that provides two solutions: 1. use CATIA Laws and 2. use Excel macro to compute involute coordinates for CATIA

Last edited:


New member
Thanks that's helpful. I suppose if u want to use it to create a Gear it will be too complicated to be worth it. My idea was to make one and just change the parameters to become other sizes.