I'm currently working on a pvc saber with an interior diameter of only 1" (a 1" blade fits perfectly into it, so I imaging it's the ID of the typical MHS blade holder).
What battery packs would fit? Aren't most designed to work with a 1.5" ID? I'm thinking the 2 AA holder might fit, but is that enough juice to run a blue Luxeon Rebel Star?
I'm not doing sound, as a speaker doesn't fit either.