Edit Revit MASS in-Place

[brianwclayton1969]

Evening Revit users,

I'm having an issue with a dome (see attached pics), I want to make a dome design, with 180 degree opening but the back end doesn't need to touch the ground.

Does anyone know how to adjust or determine how to far back the dome goes. In one of me pic you will see how far the back end extends, I want to control how far it extends. I have a pic of the Existing and a pic on what it should look like. I used the MASS IN-PLACE tool with the revolve tool.

Every bit of assistance would be greatly appreciated. 

Brian

[ToanDN]

Like this?  Use a void in the mass to cut it.

[barthbradley]

Elliptical: 

[brianwclayton1969]

barth,

I'm trying to get my dome to look and function like yours. 

When I used DOME from the Revit library, (insert DOME, component) I didn't do Mass-in place.

Either way the dome doesn't rotate on the axis from the middle in the positive direction it either pivots like the attached pics. 

What am I doing wrong?

Thanks

[barthbradley]