I've been experimenting with ABS for printing the prototype drive wheel for my BB-8, but it was never perfect. Cracks would appear the taller the object was or the layers would not be perfectly aligned with the curved shapes. I've decided to break from my use of HIPS and ABS and try PLA instead. So far the prints are coming out perfect. Everything lines up right, the curves are perfect, and there's no shrinking that I can see.
Unfortunately PLA is not going to be strong enough to use in the actual BB-8. The plan is still to take these prints and use them as positive for molds where I can hopefully quickly mass produce the parts I need to form the drive wheel. Progress is slow, but I have a trash can full of failed HIPS and ABS prints!
The green print is PLA (left image), absolutely beautiful.