How much was accomplished with the practical BB-8 prop?

Question

For Star Wars: The Force Awakens, they built a (multiple?) practical BB-8 prop. They brought it to D23 last year, where they showed it rolling around, doing the basic movement you see BB-8 doing in the film. But in the film, we see BB-8 having compartments containing tools they deploy as needed. Were these compartments part of the practical BB-8 prop, did they have specialized BB-8s that were used in these scenes, or were these parts of the film accomplished using some kind of SFX in post-production?

How much of the film was accomplished via the practical BB-8 prop?

Answer 1

Bill Hader and Ben Schwartz were the so-called vocal consultants for the droid, and Dave Chapman and Brian Herring were the puppeteers. There were a total of 7 different droids used in filming, who each had their own separate purposes (they varied in physicality) and even had their own nicknames, such as "bowling ball", for fast shots, or the the "wiggler", for close up shots that showed smaller movements.

Each and every single shot involving BB-8 was performed by the actual droid itself and was either a rod puppet or a remote-controlled robot. The one most prominent model was the puppet, which was controlled by Chapman and Herring. There were also static models present. A fully operational self-contained robot actually wasn't too practical, so most of the scenes where he is shown "walking" actually involved the puppet, where the rods were removed later in post production.

The remote-control version you saw was only created for promotional events after filming had finished.