I saw this problem been asked before but I did not find the solution.

I have a spiral equation like :

X = [ R1 + (R2-R1) * (t + f*sin(2*pi*t)) ] cos (wt)

Y = [ R1 + (R2-R1) * (t + f*sin(2*pi*t)) ] sin (wt)

and t varies between 0 to 1

All parameters R1, R2, f and w are defined as global parameters and linked to a dimension in the model. When I change R1 and R2 and rebuild it, the sketch and the corresponding feature (a cut) updates automatically, but changing w or f (and rebuilding), I need to open the curve equation and update it or double click on one of the other dimensions in the model like R1, R2 and rebuild from dimension box opens to have updated shape of the sketch and feature. Just to make sure, the exact names of dimensions used in the equation and it looks like x = [ "DS1@Sketch1" + ("DS2@Sketch1" - "DS1@Sketch1") * ...] . I was wondering how two variables in the same equation can act differently?

Has anybody solved this issue?

Thanks

Hi Nima

I strongly suggest you to use design table for define equation between parameters .

Excel has a very good relation with equations and it is a very very good alternative for poor equation in SW.