How to make cover of the backward curved impeller centrifugal blower in Autodesk inventor

Centrifugal blower with variable width backward curved blade dimension. I didn't know how to make cover of this blower. File is attached

2 Answers

You might have a better opportunity of receiving help if you add a picture of what you are trying to achieve. Often times, general modeling techniques can be explained in a universal way that might be of some use, even if not specific to the native modeling format.

heres your file