[PSUBS-MAILIST] machining q ball

[hank pronk via Personal_Submersibles]

help!
I tried to machine a q ball today as an experiment before the proper one arrives.  I put tape around it and put it in a 3 jaw chuck and while drilling the hole through it cracked.  Do I need to make a fixture to hold the q ball steady maybe?  I made a home made o-ring groove cutter and that worked perfect.  The q ball is very brittle, but machines very nice.  Any ideas would be appreciated.
Hank