You don’t need to have mechanical innards to roll around like BB-8. Do what Imgur user jtoeman did and construct the droid from paper mache. He used an emoji beach ball for the body — he had to use something big enough to fit around his frame so small balloons wouldn’t do the trick. He then used paper mache techniques. It took a long time to cover a 56″ ball completely. He used large strips of paper, but even with that adjustment, the process was still time consuming. He used a yoga ball base for BB-8’s head. He had to use a space heater to help with drying time. A couple in-progress photos:
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.