So I am drawing a spur gear tooth using an equation driven spline.  I am using the parametric equations (base diameter/2)*(cos(t)+t*sin(t)) and (base diameter/2)*(sin(t)-t*cos(t))

When I do that I get a couple problems depending on how i I do it

when I use just numbers like (1.94/2)*(cos....)

i get the spline that can be trimmed to the adendum but does not touch the base circle. 

If i do it this way i can not change it using a design table.

If i link it using equations such as ("base@gear"/2)*(cos........)

it wont solve.  Why can't I use equations linked to other dimensions/equations?

I have tried changing the dimesion base from an equation to just a numerical value but still get the same result. 

Is there a way to do this using my base dimension?