500mm poly hemisphere jig for BB-8 development

thingiverse

https://youtu.be/yBkpAqBZCfI Built to Hold California Quality Plastics 20" Polycarbonate with No Flange Hemisphere https://www.calplastics.com/ Print the Hub and 3 of the Arms Insert M5x5mm Brass Knurled Inserts into the Hub by Placing Them on the Tip of a Soldering Iron and Pressing into the Plastic https://smile.amazon.com/gp/product/B01IYMMJRW Use M5x25mm Machine Screws from Any Hardware Store or Here https://www.ebay.com/itm/M5-Pan-Head-Screw-Assortment-Kit/152139948277 Using 3 Ball Transfer Units: https://smile.amazon.com/gp/product/B00OK6BPQS The Holes for Bearings are Oversized, but the Weight of the Sphere Keeps Them in Place; You Could Add a Dab of Hot Glue to Secure Them If Desired It's Also Recommended to Use WD40 or Super Lube Synthetic Grease on 3D Printed Gears to Reduce Noise and Prolong Their Life The Holes in the Arms Allow for Clamping to a Bench, and Rubber Feet or a Rubber Mat Can Be Added for Stability When Placing It on the Ground.