1. A method of creating assemblies of computer aided design (CAD) objects with a CAD application executing on an electronic device, comprising: providing a first model object in a modeling space of the CAD application, the first model object having a first connector, the first connector defined by a position and orientation in a local coordinate system of the first model object; providing a second model object in the modeling space of the CAD application, the second model object having a second connector defined by a position and orientation in a local coordinate system of the second model object; receiving an instruction in the user interface of the CAD application that the first model object is to be connected via the first connector to the second connector to the second model object; and establishing a connection between the first model object and the second model object by recording invariant information about each connector, the invariant information to indicate the position and orientation of the second connector in the local coordinate system of the first model object within the first connector, and to indicate the position and orientation of the first connector in the local coordinate system of the second model object within the second connector.