Adjust the Bounding Box on new Master shapes

I want to create custom master shapes in a stencil. Specifically, I'm creating valves similar to those found in Process Engineering > Valves and Fittings

I want the bounding box when you drop the shape to be a perfect square around the center of the valve, similar to the Powered Valve shape. Once I get this to work, it should align properly with other valves.

If you want to build your shape from scratch:

• Create a rectangle the size of your intended bounding box.
• Click Home / Arrange / Group / Convert to Group
• Open the ShapeSheet of you new group shape and set the LockCalcWH cell in the Protection section to 1 (this will prevent the bounding box from resizing when geometry sits outside of the intended area.)
• Position your valve shape over the group shape then drag select all of them and a click Group / Add to Group

If you're wanting to modify the 'wrong' shape from your image, (ie where the alignment box completely encloses all of the sub-shapes / geometry) - then you'll need to change the geometry of sub-shape sizes which are probably defined relative to the size of the outer (group) shape. If it is already a group shape, you might find it easier to ungroup and then follow the steps above to regroup.

Bear in mind that if you ungroup you will lose any Shape Data and referencing cells defined in the group shape and these will need to be reapplied to the new group.