I have over the years acquired a collection of vintage glass electrical insulators. I've always thought that they would make wonderful Andybot heads but I have never drilled holes in glass before. I feared shattering the insulators. Welp, I bit the bullet and ordered some glass cutting drill bits, watched a whole lotta Youtube videos and viola! The secret I found was to maintain a water source to the bit head while drilling. A neat trick I saw was using a water bottle with a hole poked into it and adjusting the flow with the cap. The more you know.
Whitall Tatum No.3