How to make 3D model of cilinder with curve duct
I will not say anything about Autocad but I will give you this tutorial for Inventor...
There more than one solutions to your problem so any different opinion should be considered... (e.g.By using circular pattern)
Some links below they will give you additional ideas
However mine is totally different...
P.S. find attached my file for more details but it is in INVENTOR 2013 sorry for that...!
2.Revolve your cylinder (Easy one... ;P)
3.Split the Cylinder into individual faces... You actually define the boundaries of the path...
4. Use Thicken tool to define the depth of your path
Well That's it...