Of course a major consideration is your Mill, my mill a Clausing 8520 has a moving Spindle (2 3/4") and a Movable Knee (15") so I could not have
a fixed light source or I would have to constantly be fixing the aim.

The ring is a COB LED Angel Eye Headlight Accent Light

I put all of the pictures on my website .

I could easily drive my LED with a 12 volt battery.