Dry fit of the CDs over the fluorescent bulb indicated that it is just a little bit too big. Goes over the electronic prong but not the bulb itself. I will have to make the hole bigger. I was hoping to avoid that!

This is the center of a CD before it is enlarged.

To enlarge the hole on the CD I used a tapered grinding bit. Placed CDs on a piece of Styrofoam to prevent scratching. The drill press made this fairly easily. The tapered grinding bit would self center the hole which also helped the process.

Grind a little bit on one side then flip it over and grind a little bit on the other side. Every CD seamed to be made of a different quality or type of plastic. Some would melt more than grind away. It just meant using a little less pressure and some more time. After it looked right I would test each one on the bulb to make sure it would fit.

This is the center of a CD after it is enlarged. Only a small difference.

After enlarging the center I had to make another hole for a wire to connect to the top of the bulb. I made a jig for the drill press to do this.

I wanted the hole the same distance from the center each time. To create the jig I drilled a 1/4" hole all the way through a board. then drilled another one larger to an exact depth so that enough of the grinding bit poked out to align the CDs.