Making That Wide Angle Finder

 I need a way to hold the lens in a weird PVC part that slides over the end of the 2" tube.  

But I also need to make sure it is held securely against the front.  So I cut a piece of 2" tube about 3/4" long.  I will slit this so it locks the lens in position and screws hold it in the weird fitting.  The internal lens holder and external tube need holes that are exactly 120 degrees apart so...

The internal lens holder sits in a three jaw chuck, which screws on to a rotating CNC table, which is attached to a tilting table at 90 degrees.  If this had many features, I would write a program.  Instead, I use semiautomatic mode to position the center drill at top of tube, tell it to cut to 0,5" down, back up, then rotate 120 degrees.