How can I create a curve defined by a function or by coordinates?

Kitepower_main2015

I want to create a curve starting from a given function.
For example I want to create circle using the function x^2+y^2=1

Or, I want to create a sketch in which a curve goes through a set of coordinates. For example I want to create a NACA airfoil profile given the coordinates present in this website:
http://airfoiltools.com/airfoil/details?airfoil=naca4418-il

Thank you very much for your help.

bradley_sauln

Hey @michele_portioli861, I recommend that you start at our custom airfoil profile feature that uses NACA profiles: https://cad.onshape.com/documents/4bf18c75321ea2c8c2ea770d/w/978aece63f59e09169309756/e/b319e7a87bba701e3e02a0fa

You can take a look at the feature (even add it to your toolbar) and even see the code used to create it to work on one for your own specific use case. 

More info on using featurescript can be found here: https://www.onshape.com/featurescript

konstantin_shiriazdanov

don't think you can currently create curves corresponding to implicit equations like f(x,y)=0. though curves defined by equations like y=f(x) or (x,y) = f(t) are possible with the help of Parametric curve FS by @mahir
https://cad.onshape.com/documents/578ff8b3e4b0e65410fcfda3
if you are interested in kinematic curves there is a Curve generator custom feature for creating trajectories of points of planar mechanisms
the spline through a number of points is possible as well with the help of custom features, but if to speak particularly about airfoils there is Foils custom feature with a number of builtin profiles (don't know if it is the link to the original document)
https://cad.onshape.com/documents/972dc31f395640d97dd6edca/w/8125816b48d1d07ebf0af701/e/b0dd208496a64d28d34778f4

bradley_sauln

Hey @michele_portioli861, I recommend that you start at our custom airfoil profile feature that uses NACA profiles: https://cad.onshape.com/documents/4bf18c75321ea2c8c2ea770d/w/978aece63f59e09169309756/e/b319e7a87bba701e3e02a0fa

You can take a look at the feature (even add it to your toolbar) and even see the code used to create it to work on one for your own specific use case. 

More info on using featurescript can be found here: https://www.onshape.com/featurescript

konstantin_shiriazdanov

don't think you can currently create curves corresponding to implicit equations like f(x,y)=0. though curves defined by equations like y=f(x) or (x,y) = f(t) are possible with the help of Parametric curve FS by @mahir
https://cad.onshape.com/documents/578ff8b3e4b0e65410fcfda3
if you are interested in kinematic curves there is a Curve generator custom feature for creating trajectories of points of planar mechanisms
the spline through a number of points is possible as well with the help of custom features, but if to speak particularly about airfoils there is Foils custom feature with a number of builtin profiles (don't know if it is the link to the original document)
https://cad.onshape.com/documents/972dc31f395640d97dd6edca/w/8125816b48d1d07ebf0af701/e/b0dd208496a64d28d34778f4

Kitepower_main2015

Thanks for your fast answer. Now I`m using the airfoil profile feature and I really like it. Probably in the future I will also try the Parametric curve FS.

Thanks for your help!