This is a guide on how to build a reasonably accurate jig for drilling a hole in a sphere with a hand drill. Following this step by step is very important to get successful results. There are basic measurement skills involved. The more accurate the measurement combined with the ability to match that measurement to the proper tool, the more successful your results will be. There is probably room for improvement to this technique.
Step 1: Parts & tool list
•bolts(2), washers(2 or 4) & nuts(2)
•hole saw or spade bit that corresponds to the size of the ball