Hi all,

I'm trying to draw an equation driven curve that would use global or local variable. SW 12 documentation clearly state :

*"You cannot use global variables directly for equation driven curves. However, you can create a global variable and associate it with a dimension, then use the dimension in the equation for the curve."*

This is a serious limitation. Variables can be either positive or negative but dimensions in general can't (?). Variable can be really small like 1e-9. Dimensions can't.

So my question is : Is there a work around ?

If not, how do I complain to Solidworks so they fix that problem ?

Finally, I found that, in the equation driven curve editor, number likes **1.2E-6** is not understood correctly by solidworks. One must write **1.2*10^(-6)**.

Anyone ever noted that ?

How do I report that ?

Thanks

Philippe

P.S. Below, an example of the kind of equation I want to drive with variables. This is for the sag of an asphere lens. I want to replace numbers like -8.5995732*10^(-9) by a variable. So when the design of the lens changes, I don't have to dig the number. I will just need to edit the table of global variables.D3@ESQUISSE1 is the radius of curvature of the lens which is a big number and is a readily available dimension so I can use it.

-1*(((1/"D3@ESQUISSE1")*(x^2))/(1+sqrt(1-x^2/("D3@ESQUISSE1"^2)))-8.5995732*10^(-9)*x^4+7.8575671*10^(-14)*x^6-8.3052033*10^(-19)*x^8)

to report enhacements that you want to the software, you go to the customer portal and enter an enhancement request (sometimes called an ER)

a work around for the negative values is to use an offset.

say that the value in the equation is -1 to 1, make the global variable -1 to 1, make a dim equal to the variable+2, and in the equation, use the dim-2.