I don't think that you want to do a pad operation in this case, or at least not only a pad operation, since that leaves you with a flat face connected to circular surfaces. I would recommend extending the shape beyond the boundaries of the top and bottom 'plates' and then to follow up with a clean-up groove revolved around the z axis.
![ND Academy, FreeCAD 0.20, Bind Two Cylinders? [CAD Model for 3D Printing]](http://i.ytimg.com/vi/F0DKa7HxH3U/mqdefault.jpg)
Another very helpful video. Thanks.
I don't think that you want to do a pad operation in this case, or at least not only a pad operation, since that leaves you with a flat face connected to circular surfaces. I would recommend extending the shape beyond the boundaries of the top and bottom 'plates' and then to follow up with a clean-up groove revolved around the z axis.