Variable Trim Over Window

[bclarch]

I can't get this family to behave the way that I want it to. Perhaps I am asking too much of it. It is a trim sweep made to mimic a palladian window head. I want to be able to control the following using instance parameters.

1. Overall width.
2. Adjust the arch height (radius) without affecting the width.
3. Adjust the arch width (arc length) without affecting the height.

I accomplished #1 by locking the ends of the sweep to ref planes. No sweat.
I accomplished #2 (to a certain degree) by locating the center of the arc in the sweep path at the intersection of two ref planes. Moving the horizontal plane up or down causes the arc's radius to change even though it isn't actually locked to the plane. I made the plane a strong reference which is probably why the arc center is sticking to it.
I have had no luck with #3. There doesn't seem to be any way to constrain the arc in a way that allows the ends to flex symmetrically while keeping the top center point of the arc fixed. I suspect that it has something to do with the "keep concentric" feature that you have to deal with when editing arcs.

If one of the family gurus out there could take a look at this I would appreciate it. It would even be helpful to know if it simply can't be done so that I can stop beating my head against the wall.

Oh yeah, the file is in release 7. I don't like upgrading a project in the middle, especially since the project that this is to be used for is also our first workset enabled project.

[Rhythmick]

No Guru here!!, but was able to accomplish by adding a dimension parameter from the trim base reference plane to the top of the arc sweep path = Arc Height.
I dimensioned the arc section of the sweep path from the two end points equal with the center line and dimensioned end point to end point of the arc for the parameter = Arc Width.

EDIT: I removed the relationship with the sweep profile <by sketch> and the "Top of Arc (path)" reference plane, It was causing conflicts when changing the profile to ones you had loaded.
I also removed uneeded reference planes.

[bclarch]

Thanks Mike. Works great. It looks like the key was to control the sweep path with dimensions instead of trying to drive everything with ref planes. Thanks again.