Well I can always get my sprocket to spine Tru but when I look down at it on the bike it wobble s left to right so I made a ring that not only puts the sprocket in the centre but gives a flat surface to sit on .well just an idea that works great .
Yes, works well on some hubs - other hubs don't protrude as much. One needs to be careful that it doesn't prevent the sprocket from being drawn completely tight onto rubber fitting though.
I tried the ring with out anything else/rubber stock donut and it pulls the Spokes in to the sprocket so no good I put the stock donut in and its pretty thick so I made one to size from conveyor belt. But the sprocket still sits on the ring when done up .. another idea was to cut some pipe down to use like spacers between the sprocket and the 3 plates but you would still need the rubber donut .